Salomon S Lab Equipe 10 Classic Zero Skis- review

One of the many classic technique ski types now available from numerous manufacturers is the “zero”, a ski specifically designed to give good to excellent kick at and around 0 degrees C (32F) in new wet and morphing snow conditions. Since the introduction of these skis over 5 years ago, the “zero” has become a requisite part of any competitive skier’s fleet of skis.

The Sun Valley area was visited by a true “Cascades” type weather pattern in late November and early December 2012. A super wet, near 0 centigrade snow storm coated the entire upper Wood River Valley (it was all rain in Sun Valley) with dense, wet snow to depths up to about 4 feet. The conifers have the classic totally “plastered” look, just like one sees in the Cascades. This weather pattern lead to snow conditions in the Galena Lodge area that were classic “zero” conditions. I had just received a pair of Salomon Equipe 10 Classic Zeros and this was an ideal time to try them out.




Many classic technique skiers in the inland Rockies, have been reticent to invest in a “zero” ski because they (incorrectly) contend that conditions in such areas seldom call for the “zero”. In typical bucolic “blue hard wax” kick days, thoughts about “zeros” quickly disappear but, come race day and a warm front with wet snow and suddenly you are “up the creek”, so to speak, if you do not have a pair of “zeros” in your quiver. This happened a couple of years ago at the Teton Ridge 28 km classic race in Tetonia, ID. The only reliable kick that day came from “zeros” and the drop-out rate (and associated  “frustration rate”) by competitors was high as the “hard wax over klister” solution was either marginal or not sufficiently durable for the entire race. Those who showed up with “zeros” had a great day. Now, consider that you might have trained specifically for that race and you quickly realize the value of your investment in “zeros”.

Here in Sun Valley (which is known as a “dry” snow area, although it seems to be getting wetter and wetter) over the past few years we have used “zeros” at least 10-15 times per 150 day season, or 7%-10% of the days. On many of these days no ski of racing grade would work and this would have resulted in a lost day of classic skiing. One could use crowns but we all know the drawbacks there. I have heard similar comments about the usefulness of “zeros” from other skiers in numerous other inland, “dry” snow areas.  Simply put the “zero” ski is an essential element to your ski fleet, even in such “dry” snow areas.

Salomon S Lab Equipe 10 Zero ski

I switched from Fischer skis to Salomon skis after a long conversation with our ski adviser and the improving capabilities of Salomon in the ski design and manufacture arena. He convinced me that Salomon had come a long way and as of the 2011 model year was entirely in control of the design and manufacture at the Austrian ski manufacture facility shared with corporate sibling Atomic Ski.

Salomon is starting to put their stamp on Nordic ski design with the softground skating ski (review forthcoming) being an example and this “zero” ski being another. I have always had faith in Salomon’s ability to challenge the leading edge of technology and design and it is good to see they are following through with their Nordic skis.

One consequence of switching from Fischer to Salomon is that I have a ready supply of hand-picked Fischer skis for comparison testing. In this case a pair of 2011/12 Fischer “zeros” are used in 1-to-1 testing with the 2012/13 Salomon Equipe 10 “zero” ski. Comparisons will be referred to throughout this review.


Salomon have designed different flex distributions for their cold and warm classic skis. The warm condition skis have a more “peaked” pressure distribution fore and aft than the cold conditions ski. This presumably allows for more water displacement and perhaps better glide in wet conditions. The zero ski, of course, has the “warm” condition flex pattern. This flex pattern is partly achieved by utilization of a full carbon fiber layer in the build-up stack.

Important note: Flex, as many of you know, is by far the most important aspect of choosing a ski. Choosing the proper flex for your weight and skiing style is not, however, a straight forward process. Although it might be possible to select a pair of symmetric, well-matched flex pattern “off the rack” skis at a ski shop, it is highly improbable and therefore best avoided.

There exists a growing business of  experienced “hand pickers” who go to the ski factories over the summer and pick skis out for their clients. This process begins by selecting through the designated “race stock” to a group of as few as 20% 0f the initial number to find true “race stock” quality and symmetry. From this much reduced group of skis, the proper flex for each client’s weight, aggressiveness, and style are chosen by the pickers. As I understand it , after this hand picking, the rest of the race stock goes to warehouses around the world. Often when a ski shop informs you that your skis will be “hand picked” for your parameters by “their guy” at whatever ski company, it is this stock that they are choosing from. Obviously, it is not necessarily the best stock to be choosing from. Worse still are the “rack” skis in the shop. If you are serious about your skiing do not buy “rack” skis or even “company guy” skis; absolutely stay away from store rack skis (if you are serious you probably already know this but there is no problem with stating the obvious). Invest in skis “hand picked” by experts for you. You will otherwise risk paying list price for “dogs”. Handpicking, which costs about $100/pair in addition to the list price,  is a very good investment as these properly picked skis will be be your best friends for many years. In fact, I know many Nordic Olympians who are still using their race stock classic skis from as far back as the late 80’s and early 90’s- and they are still competitively “fast” skis (they are not as stable as modern skis but if your skills are sufficient such skis can be as fast as anything out there). 

These Salomon Zeros were “hand picked” for me this past summer by our ski adviser. These skis are compared to a pair of Fischer RCS classic zeros also “hand picked” for me last year.

Grip Area

There appears to be nothing new here as all of the major manufacturers have utilized some version of the same technology to obtain grip in these difficult waxing conditions. The grip area consists of a rubberized, “hairy” or “fuzzy”, base region made of rubber mixed in with normal base material. This area needs to be “activated” with simple random circular sanding with 100-150 grit abrasive paper (aluminum oxide grit papers seem to work the best). The professionals use a random orbit electric sanding tool with the same paper but it is not necessary to use such a tool to obtain similar results- the hand sanding works just fine. Once you gain experience with the zeros you might want to start trying them in “non-zero” conditions. This will require utilizing different degrees of “hairiness” and therefore different grits of abrasive paper and aggressiveness with the paper. Some report the zeros as useful down to the -7C (20F) range, depending on snow conditions. Others have used the zeros as a waxable ski and just sanded off the wax when they are to be used in a “hairy” state. I have not experimented with any of these extended range uses so I will not comment on the efficacy, but I might give some of this a try and report back here.

Close-up view of the grip area material of the Salomon Equipe 10 zero ski. Note random scratches from abrasive paper "activation"

Close-up view of the grip area material of the Salomon S Lab Equipe 10 zero ski. Note random scratches from abrasive paper “activation”. This “activation” produces the necessary “hairies” fundamental to the grip physics.

The grip area must be treated with some sort of deicing compound. Swix sells a flourinated spray product specifically for this purpose called, appropriately “zero spray”. They sell two types a 100% flourinated “zero” and “zero 70”, the 70 is the “economy” version and I have had nothing but issues with the “economy” product. The 100% flourinated “zero” product works quite well but is very expensive (about $80 at BNS). The “economy” version is much cheaper (about $30 at BNS) but based on my experience I cannot recommend it, just invest in the 100% product. It is quite frustrating to be out there about 15 km into a ski and have icing on the grip area- it not only reduces the grip but it severely detracts from glide to the point of making the skis unskiable.

I have been told that there are numerous other durable and cheaper treatments for the glide area including use of 100% flouro-block rubbing, etc. Having not tried anything other than the zero sprays I will not comment further on these alternatives. I do know that many of the elite racing techs will use some version of alternative methods to prevent icing.

Glide area

The glide area is no different than on any other warm conditions Salomon Equipe 10 ski. The glide areas are treated just as you would a conventional classic ski. I had a warm weather grind put on these skis but Salomon provides the product with their own grind. Although these factory grinds are getting better, the custom grinds available at ski tuning facilities nationwide are, in my experience, typically superior in most conditions where an objective test is employed.


As I indicated at the outset, we have had ample opportunity to use the zero skis here in Sun Valley this season and I have done just that. I have been on these zeros for six sessions and a total of about 150 km. The longest training session was 42 km. In each instance the grip was solid and the glide remarkable. In 5 of the 6 sessions no waxed-ski alternative was yielding reliable grip. In the one session that a waxed ski could perform, the waxed ski was significantly slower than the zero. In all cases I would probably have opted to not ski classic given the difficulties in waxing. The zeros were a true solution and allowed me to continue with classic skiing independent of the conditions- something that is very important to me.

The Salomon Equipe 10 Zero ski.

The Salomon S Lab Equipe 10 Zero ski.

I tested the Salomon Equipe 10 zeros (2012/13) against the Fischer RCS zero (2011/12) in a head to head comparison in “classic” zero conditions with identical grip prep (including “zero spray”) and glide wax on a timed 1.5 km loop (with two hills and numerous slow speed and high speed turns) repeated 3 times for each set of skis. This type of testing is preferred when comparing two sets of skis because you generate both analytic data (lap time and max downhill speed) and subjective data like which pair felt faster and skied the transitions more smoothly. Although the skis were close I will give the edge to the Salomons as they had consistently faster loop times, max downhill speed, and they “felt” faster on the ups. Suffice it to say that the Salomon Equipe 10 zeros are at least the equivalent of the Fischer RCS offering. Given the success of the Fischer ski, it is safe to conclude that the Salomon ski as good as any “zero” ski currently on the market.


Salomon have produced a top quality, very fast zero ski offering that can compete with any other version currently available.


Numbers for the year, training recap, and goals for 2013

My training “year” follows a December to December pattern due to a transition from trail running to skiing right around late November- early December. It is a good time to tally the numbers, do some critical review, and put together a training plan for the coming year.

The Numbers

I targeted about 700 hours for the year and came surprisingly close to that number without any “manipulation”. This is strictly fortuitous, but because this training year has been nothing but pleasurable, it has given me some confidence that I can now, after a couple of years of serious and consistent training, start to push the numbers without any great concern for breakdown. It is at times like this when ones full potential is within reach. I am grateful that I have the opportunity to pursue it.

As far as vertical ascention, I really had no sense of what a typical year of training would total up to. The 500,000+ feet this past year was a surprise and averages out to about 1,450 feet of ascention per day. I know I can handle more vertical so I am considering a target  for the coming year, maybe 700,000 feet (about an average of 1,900 feet per day).


As I review the past year of training it is a bit of a struggle to derive some meaningful metrics, associated clarity, and, ultimately, direction from the numbers. Evaluation of time, intensity, distance, and vertical ascention are all important inputs to arrive at functional metrics that can provide guidance with training plans going forward. In previous posts I have used a derivative metric called “intensity minutes”, aka training impulse (“TRIMP”). Although this metric nicely incorporates both training time and intensity (i.e. a measure of the “quality” of the training session), the metric differs significantly in magnitude for different sports. Specific to my training in the sports of trail running and Nordic skiing, the magnitude of the “intensity minutes” is quite different for the same training load. It seems apparent that this is the case due to the amount of time one can run versus ski. I find that, on average, a 2 hour ski is about equivalent to a 1.5 hr run which equates to an approximately 30% difference in TRIMP. This is likely due to the significant incorporation of the upper body in skiing. Given this empirical and functional difference in the two sports w/r/t TRIMP, the training seasons must be evaluated separately and with different metric magnitudes. Periodization, of course, will not be substantially different.

The goal here is to glean from this analysis the following:

  • magnitudes – what are the magnitudes of TRIMP, time, distance, and vertical ascention that make sense for me?
  • capabilities – what are the magnitudes of training variables that I can consistently “support”  through a season?
  • combinations – what combinations of sessions are effective and supportable?

and, most importantly,

  • direction – for detailed training plan design


Analysis of the training data suggests that I am capable of consistently supporting a 7 day total of about 2700 intensity minutes of TRIMP in skiing and about 2200 intensity minutes of TRIMP in trail running. These data are important because it sets the combination of time, intensity, and distance that can be reliably included in a week of training. In addition, variations in the amount of TRIMP for periodization can be derived from the available data as well. In this case the dynamic range in training  TRIMP for skiing is about +/-500 intensity minute units and for trail running this range is about +/-1000 intensity minute units. What this means is that a “hard” running week will target a value of about 3000 TRIMP and the same “hard” week for skiing would be targeted at about 3200 TRIMP. Likewise an “easy” week for running would be about 1000 TRIMP and for skiing it would be about 2200 TRIMP. The challenge is to take this information and develop a training plan around key races.

For running it feels like somewhere around 80 miles per week is a supportable quantity. I may try to push this up next season but I have heard from others in my age range (and with a lot of experience and great results in ultra running racing) that they have difficulty dong much more than 80 miles per week without developing “issues”. I have intentions of bringing my minimum run distance up to 20 km (12 miles) as this will ensure a minimum of about 85 miles per week that I could build off to see what happens to my body when I start to reach into the 100 mile+ per week regime. However, distance will always be second fiddle to quality- even I have seen way too many good runners focus on distance and see their performance decline.

As far as skiing, given the significant lack of impact damage, I can easily handle 200 km+ (120 miles) per week without any negative side effects. Once again though, quality is king and this is even more important in Nordic skiing where the races are much shorter than ultras (the longest Nordic skiing race will be about a maximum of 2.5 hours). So some super high intensity intervals and hill repeats are very important to maximize performance for the shorter races (10 km-30 km). I have no focus on distance in skiing, just time, particularly early in the season. The other element that plays in here is that the snow conditions can radically alter the pace and it is distinctly possible to cover twice the distance on a fast snow day than on a slow snow day, so there really is no basis for using distance as a primary metric for Nordic ski training. Distance has much more influence in trail running.

I am still experimenting with training week “combinations” (e.g. a hard running week of vertical with distance (3000 TRIMP) combined with a recovery running week dominated by distance (1000 TRIMP)) that work together to maximize absorption of the training load for optimal cardiovascular, muscular, and skeletal development.

I have entertained thoughts that I can “support” a higher TRIMP (and therefore higher intensity/time/distance/vertical) on average than I have this past year and therefore my forward-going training plan will push the TRIMP values and we will see how that works out. I know from past training “careers” that my ability to absorb volume is greater than what I am presently doing, but then again, I am 30 years older than when I last trained at this volume. Time will tell.

Given these training load parameters and successful combination weeks, much of the necessary input for development of a detailed first order training plan is established. The synthesis of a plan can be completed by your coach (if you have one) or directly by you. I prefer to interact with a coach in a consultive manner where I come up with a draft plan and my coach edits this plan and we come to consensus. The consulting coach can then be tapped periodically for adjustments or revamps as needed. I like this arrangement because, for whatever reason, I seem to be more invested in the plan and therefore  more committed to the details on a day-to-day basis. But that is me.


I will now present the detailed training data that supports the “take-aways” summarized above. There is a lot of data here- two sports, 4 input variables, and a derived metric (TRIMP) for an  entire 700 hour year of training. You may not have the interest to go through it but it might be worthwhile to do a pass through if for no other reason than to see how another athlete is evaluating their training. I am putting this information up for a couple of reasons- first to document the training year for planning and future reference and second to elicit any comments from interested readers. Although I have direct contact with a coach (consulting) and incidental contact with numerous other coaches on a regular basis, I still find that interaction with and input from a wide variety of athletes is very valuable. Your comments are welcome and greatly appreciated.

Detailed data graphics

The following eight graphics present all of the training data in a format that includes graphical representation of 7 day rolling total (blue), 7 day rolling average (green), and daily (red) data over the training period for the ski season (18 Nov 2011-8 Apr 2012) and, separately, the running season (9 Apr 2012-19 Nov 2012). The data presented are TRIMP, distance, time, and vertical ascention.

Ski Season

This past ski season represented a return to racing for me. I had not ski raced in about 20 years. My past racing focused on skating but I have come to a greater appreciation of the classic technique and this is now my focus. Although I skate regularly, classic is the passion and is also the preferable race style for me. I prepared for and competed in two races with reasonable results and I am looking forward to “really” racing this year.

Slide09Slide11Slide15Slide13Focusing on the TRIMP graph, the periodization is quite evident where a slow 3 week buildup to consistent high quality was instituted in the early season. This was followed by a one week recovery period and then a ramp up to high quality for about two weeks prior to the first race. This high quality period included significant interval sessions and numerous hill repeat sessions at race pace as well as long (20 km+) tempo skis. A five day taper prior to the race was used and my performance exceeded expectation. It had been about 25 years since I raced in a Nordic event and I was “relearning” much about pacing and strategy.

The buildup to the second race was similar, starting out with a recovery week, then a week focused on technique drills and easy distance, followed by a very high intensity week (3500 TRIMP) that worked on both LT and VO2 max. A recovery week was then followed by a second high intensity week similar to the first one. I could definitely feel this training load and increased my sleeping time accordingly. An easy week following this and then a slightly lower intensity week to allow for full absorption of the period. A taper and then the race. The race went very well, stayed in control of the lead pack of 10 skiers throughout but let one guy get away in the last 10 km. Chalk that up to experience. The remainder of the lead pack jostled around and I finally conjured up the confidence to make a push in the last 3 km. Only 4 others were able to stay with me but I did a bit too much work and payed for it in the last 250 meters. But finishing 6th overall with a bunch of 20 and 30 somethings sounded like progress to me.

Running Season

This was my first season of training for trail ultramarathons and included my first two ultramarathon races (53 km and 70 km). It was also the first season of running focus in over 25 years. After 20 years of mountain biking at the professional and expert level, I have “ditched” the bike and turned to trail running only, at least for now. In the early part of the season I transitioned to “low drop” shoes and had the requisite bout of Achilles tendonitis in late April/early May after doing a bit too much vertical. This cleared up after a couple of weeks with reduced volume and reduced vertical.

Much of this training was by “feel” as I had  no reliable calibration as to what sort of volume/intensity/vertical would be consistently supportable. What I found was that a volume base of about, on average, 1.5 to 2 hours of trail running per day worked well. At a reasonable pace of about 10 min/mile this works out to 60-80 miles per week. I set a minimum trail run distance at 15 km (9 miles) and iterated off that to include intensity and vertical with some longer runs mixed in. One goal for next season is to include many more long runs (32+ km/20+ miles) and increasing the minimum trail run distance to about 20 km/12 miles. Also, I think that I can handle significantly more vertical as this is a strength but I need to balance this with work on an identified weakness- pacing on the flats. So speed work will be worked in next year.


The training structure is fairly obvious, but here is a narrative:

  • from mid-April to mid-May- developing base aerobic training with a couple of progressions and a bout of Achilles tendonitis
  • a build up to about 17 June for a 53km race with about 7,000 feet of vertical on 23 June
  • a week of taper and then the race
  • a recovery period (about 3 days)
  • another build up to about 7 July for a 70 km race with about 11,000 feet of vertical on 14 July
  • a week of taper and then the race
  • a recovery period (about 2 days) and about 2 weeks of lower volume
  • a third build up to about 11 August for a 84 km race with about 10,000 feet of vertical on 1 September which was truncated because I decided not to do the race due to fires and associated smoke
  • a volume block from about 20 August until about 5 October
  • a recovery period of about 7 days
  • transition to ski-specific training (some running but more roller skiing)

As far as the effectiveness of this training periodization, I placed in the top ten overall (5th and 9th) in each race. A better evaluation is that in each race a nationally ranked runner participated (and won) so I can calibrate my performance on a more national level. I was within 20% of the winning time in both races, which, given that these are my first two ultramarathon races, that I have only been training for ultramarathons since April 2012, and that I am old (56) it would seem that the current training protocol is at least passable. I have a lot of skill development and lateral muscle building to do, but this is a good start. My only significant thought is that I will add more long (20+ miles) runs into the program. Time will tell if it will have any positive effect; I expect that more longer runs will help with having a strong finish. I also need to concentrate on pacing on flats and also climbing as I was in the early part of the season.

Other relevant data

One of the most important parts of designing a reliable training plan is to establish a good balance of training time spent in the 5 heart rate zones. In a prior endurance sport “career”, our coaches emphasized the importance of avoiding too much level 3 training as such training is considered, by and large, “empty” training from a competitive fitness perspective. One will feel really good during such level 3 efforts but it is not doing much (if anything) with either LT pacing or VO2 max development. Focusing on high quality level 4-5 sessions with adequate rest at level 1-2 and including technique work (typically done at level 1-2) is preferable to including too many level 3 efforts. I have always had problems abiding by this protocol and such has proven to be the case once again and represents an important goal for next season.

Presented below are the percent “time in zone” and the “TRIMP per session” distributions for the ski and running seasons.Slide1 Slide2As is clearly evident, I have allowed for level 3 efforts to dominate my training. Whilst this may be acceptable in this first year of training for racing, going forward I need to drop the level 3 and replace it with a suitable combination of level 2 and level 4 efforts. The input I have received indicates that I should target a value of about 25% of the total for level three, with a similar amount of level 2 (with a total of about 35% for level 1&2), about 35% for level 4, and the remainder 5-10% at level 5 depending on how much racing will be done. You can see that I did a better job in approaching these numbers in running than in skiing, so with the just starting skiing season I will be pumping up the level 4 sessions  and adding a few more level two sessions. In running, I think that if I increase the vertical ascention, the level 4 efforts will naturally begin to dominate as I am almost always in level 4 on the climbs on the trails in the Sun valley area.Slide3 Slide4A similar result obtains for the TRIMP distributions as was evident for the “time in zone” distributions. The one caveat is that in running, the ultra races and long tempo runs increase the very high TRIMP per session values almost to the point of consideration of throwing them out f the analysis. I have included them here because the remainder of the distribution is still fairly accurate. This highlights one of the issues with using TRIMP as a metric for ultra distance training. The long times associated with the ultra races and the longer training efforts seems to over value these particular efforts. However, it will still be functional to attempt to put a training program together that more closely approaches a bimodal distribution dominated by TRIMP per session values at about 200 and 350.

Looking  forward and inputs for 2013 training plans

This analysis has lead me to propose the following goals for the 2013 seasons:


  • increase level 4 efforts and replace level 3 efforts with true level 2 efforts
  • focus on LT pacing and tempo skis (linked to increased level 4 efforts)
  • increase long (3-4 hour) skis to keep endurance and fat burning capabilities up for the ultra running season
  • focus on racing the races and controlling the dynamics of the pack


  • increase level 4 efforts and replace level 3 efforts with true level 2 efforts
  • try increasing minimum run length to 20 km/12 miles to determine if higher distance volume has a positive effect on strong race finishes
  • include speed work to help with pacing on flats
  • increase total vertical ascention (linked with increasing level 4 efforts)
  • race more to gain experience- target 4 races including at least one 100 km race

These goals have been central input to training plan development and I have a draft plan put together for both the skiing and running seasons. Hopefully an optimal training plan will result that will require very little modification and/or revamping.

Transition to skiing

The snow arrived here on 18 November (which is typical for our area) and the transition from ultra running training to Nordic ski training has begun. This has been the first season that I have engaged in a rigorous ultra running training and racing program and it will be of interest (to me) to see what affect this has on ski training and racing. The skiing is great and is a welcome respite from running and rollerskiing.

Conditions on 23 November 2012, Galena Lodge area, Idaho

Conditions on 23 November 2012, Galena Lodge area, Idaho. Fresh cords for over 50 kms and beautiful vistas.

One aspect that I have immediately experienced while skiing is a significant increase in power in classic technique skiing. Leg push-off on the power stroke phase is noticeably stronger and balance on the subsequent glide phase is improved. I suspect this is from the substantial amount of climbing that was included in my training regimen. Hill climbing, either via running or power hiking, engages the calf muscles in a primary way as anyone will experience in their hill training. Nordic skiers traditionally develop this muscle group via hill bounding and hill climbing/running. I did not do any hill bounding this fall and replaced it with significant, lengthy (1 km+) vertical ascention running/power hiking on 20%+ grades. I did this to improve endurance on long climbs (both running and skiing). Hill bounding can help with such endurance but is more focused upon explosive power, something that an oldster like me needs to be careful about to prevent injury. Although I have never been injured doing hill bounding, I can definitely feel the stress on the connective tissue and the associated low level pain after any substantial hill bounding session. I felt that I could do much more hill climbing/running than hill bounding for the same level of connective tissue damage and that at my age this was preferred.

An orthopedist once colloquially described the slow transformation of connective tissue in the human body as the following:

jello -> rubber -> leather -> cardboard -> glass

So, starting out as jello (as an infant) then developing into rubber (until about age 25 or so) and then on to leather (up to about age 50, depending upon how abusive you have been to your body), then cardboard (up to about age 60 or so), and then into the final, “glass” stage. I am in the “cardboard” stage and therefore take appropriate precautions- like limiting the amount of hill bounding I do.

So far the transition to skiing has been going well, partly due to a good measure of rollerskiing since May and also due to a concentration on trail running with challenging vert and essentially no mountain biking. I find the mountain biking, although a reasonable cardiovascular stimulus, to be less challenging than an equivalent trail run. In addition, given a certain level of skill, the downs can be quite abusive of the upper body, particularly with a hardtail. We will see how it goes with a continued concentration on trail running, but mountain biking, for the time being, has become a very minor part of my training program.

The current program includes another week of volume (about 150-200 kms and about 14-15 hours) and then two weeks focused on intensity (primarily hill repeats and fartek) with a reasonable base volume of about 120-150 kms very easy, still with a total training time of about 15-18 hours. Fortunately we are in the process of getting “feet” of snow, at least above 7,000 feet, and significantly more terrain should open in the next day or so and it will be more enjoyable to notch the volume up to 200+ kms.

At the moment running is not happening to allow for sufficient volume on skis and to provide a “break” and let the connective tissue repair fully. Limited trail runs and power hikes will return sometime around Christmas.

Salomon Dynamics Jacket Review

Each year I update and tweak a group of clothing pieces for use in Nordic ski training and racing. Typically, two sets are sufficient to handle the spectrum of weather conditions we see here in the central Idaho mountains.

Sun Valley, as you might expect, is a very sunny place year round and particularly so in the winter, at least compared to most places that have a 5 month ski season. As such, clothing for extreme cold (-30+C/-20+F) is of limited use because, although the air mass may be very cold, the heat gain to clothing via absorption of energy from the sun can significantly alter the effect of the cold. Also, extreme cold conditions have become less and less frequent in the past 10 years, perhaps indicating a warming climate in the US Rocky Mountains. For instance we have not had a -32C/-25F temperature for over seven years. If you speak to some of the long time locals here, they will tell you that such low temperatures were common just 15 years ago. In any case, preparing for temperature minimums around about -26C/-15F is appropriate.

The extreme cold may occur for perhaps 3-5 days total so, in a ski season with 150 days the vast majority of skiing here in Sun Valley will be taking place in the -12C/+10F to 0C/+32F range. It will also typically be sunny and dry. So when I look for a group of clothing pieces for Nordic ski training in this temperature range, ventilation and breathability are critical.

The Dynamics Jacket

The past two years I have been using the Salomon XT Softshell jacket from the Salomon running collection as a basic part of my Nordic skiing clothing group.

Salomon XT Softshell running jacket- works well as a Nordic skiing training jacket as well.

I always wondered why Salomon did not include this jacket in their Nordic skiing collection as it is ideally suited to training for Nordic skiing. In previous years most of Salomon’s designated Nordic skiing jackets have been way too warm for training here in Sun Valley and I have only used the jacket and pants from the Momentum II ski collection for the extreme cold weather described above. Well, it appears that Salomon have gotten the message as they have a new Nordic jacket for F/W 2012-2013 that builds on the XT Softshell design with some refinements for Nordic- it is called the Dynamics Jacket and it is a great addition.

Salomon Dynamics Jacket for F/W 2012-2013. A great Nordic ski training jacket (and running jacket as well).

As you can see the fit of the Dynamics Jacket is bit more snug than the XT Softshell Jacket and has two vertical seams and one horizontal seam on the “ClimaWind” softshell windproof front. Also included is a nicely placed and sized pocket high up on the left side of the jacket. The pocket is perfect for a phone/music device, lip balm, or even a small (148 ml/ 5 oz) softflask fluid/fuel bottle. The pocket has a feed through for headphones.

The breast pocket of the Dynamics Jacket has a feedthrough for headphones.

The back is highly articulated with a unique “halter” shaped softshell panel in the center with highly breathable stretch woven fabric surrounding it. A large side entry vertical zip pocket is also included and is sufficiently large to carry enough fluid and fuel for at least 50 km/ 31 miles. The side-entry pocket is a thoughtful addition as horizontal pockets are difficult manage when reaching around.


Back of the Salomon Dynamics Jacket showing unique “halter” shaped softshell panel and highly breathable stretch-woven panels. Shown is one of several Women’s colorways.

The sleeves are half softshell and half highly breathable stretch woven fabric. The sleeves also have an elastic band around half of the sleeve end which is different from the XT Softshell Jacket which has an elastic “ring” around the entire sleeve end. This is half-elastic band is very functional for Nordic skiing because one can pull the sleeves over gloves and attain a relatively tight seal thereby preventing wind from going up your sleeves. One can also put gloves over the sleeve ends which was difficult with the XT Softshell Jacket.

Elastic at the sleeve ends allows for a reasonable seal with gloves in windy and/or cold conditions- a nice detail.

The sleeves are nicely articulated and allow for full body motion without fabric stretching.

Sleeves are articulated allowing for stretch-free movement.

Salomon also added a retaining clasp in the upper portion of the jacket. This was found on the XT Softshell Vest last year. I found it to be very useful as it allows one to unzip the jacket (or vest) to allow for additional ventilation without having the jacket flapping around.

Retaining clasp across the upper chest area allowing for additional ventilation without the jacket flapping around.

A simple cinching mechanism is provided at the bottom hem and is an improvement over past cinching systems in that this one uses very minimalist parts that are essentially invisible to the user. The larger, spring-loaded systems are somewhat intrusive and bulky. This simple mechanism seems better suited to such lighter weight training jackets.

Minimalist cinching system at the bottom hem is an improvement over spring-loaded equivalents. Note also the sewn-in sub-pockets in the large back pocket- perfect for phones, music devices, keys, etc.


I have had this jacket out on numerous runs from 16km (10 miles) to 35 km (20+ miles) (and rollerskiing for up to about 35 km (20+ miles)) in typical fall conditions of temperatures between 2C/35F to -8C/18F, mostly sunny  with some periodic light precipitation, although not actively raining. I have also had the jacket out in a snowstorm with significant precipitation and relatively high winds of about 32 km/h (20 mph). These conditions represent the majority of what will be present during the ski season. In all cases this jacket has performed outstandingly. From great ventilation to good wind protection, I can see that this jacket will be the mainstay in my Nordic ski training (and cold weather running) clothing group. The fit and articulation is well thought out and the various other details outlined above are much appreciated, particularly the restraining clasp.

I still need to test the Dynamics Jacket in truly cold conditions (-18c/0F) to determine the cold weather performance. If this jacket performs in cold conditions similarly to the XT Softshell Jacket, it will be fine right down to -18C provided one beefs up base layers. Anything below -18C and I switch to the Momentum II group, which provides additional thermal insulation.

One final note: I hereby request that Salomon produce a companion Dynamics Vest. I tend to use softshell vests in any sunny weather above -7C/20F and currently use the XT Softshell Vest for these conditions. Given the slightly “snugger” fit and articulation of the Dynamics Jacket, I think that a vest would be a nice addition to the Nordic clothing line. I find the Salomon Momentum II Vest to be way too warm for these conditions.


Salomon XT softshell Vest, a nice piece for Nordic ski training in sunny and relatively warm conditions (above -7C/20F). A Dynamics equivalent would be a nice addition to the Nordic clothing line.


$185. A relatively expensive jacket but you will likely get multiple years of use out of it and it can be used for running as well.

Bottom Line

A great jacket for Nordic ski training with some nice details that increase functionality.

Salomon Snowcross CS Review- Run With Confidence

I received a pair of Salomon Snowcross shoes in late September 2012 but have only just had the opportunity to run in them. The past few days we have gotten our first real snow here in the Central Idaho mountains- about 4-6 inches in Sun Valley and more than 8 inches reported up higher near Galena Summit. This has made the trails I normally run to be snow covered and ideal for trying out the Snowcross in the conditions they are designed for.

The Snowcross is a winter-specific running shoe built around the Speedcross 3 and includes an integral gaiter and associated upper design elements. I have taken them out for a couple of runs totaling about 35 km (20 miles) and this is an initial impressions review.

Design and Build

Having used Salomon nordic skiing boots exclusively since the 1980’s, it clear where much of the technology for this shoe originated. The build is high quality and has certainly used much of what Salomon has learned from the Nordic boot market. An important part of the design is the use of seamless technology throughout the upper construction.

The Salomon Snowcross CS uses much of the technology developed for Salomon Nordic skiing boots, particularly in the design and construction of the uppers.

As noted earlier, the shoe-part of the Snowcross is a Speedcross 3 which has stack heights of  19 mm (heel) and 10 mm (forefoot) yielding a drop of 9 mm. This is a bit problematic for anyone who has transitioned to low drop shoes (e.g. the 4 mm drop of the S Lab Sense or the S Lab Fellcross) as it would be most ideal to continue any winter running with a low drop shoe. More on this later.

The Speedcross 3 has generally received good reviews with the only consistent detractor being the height of the shoe and a propensity by some to turn an ankle. I have run extensively in the Speedcross 2 and a much smaller amount in the Speedcross 3 and have never had any issue with lateral instability. However, everyone’s ankles are different and there certainly is a significant spectrum of ankle strengths out there. I moved away from the Speedcross due to the need for a low drop, forefoot striking design to facilitate my natural forefoot striking tendencies. I also moved away from the Speedcross due to weight as both the low drop Fellcross and Sense are much lighter. What I found is that weight matters- a lot! But in this case I just want to enable regular running in winter conditions as a secondary activity to Nordic skiing, so weight is not as important a consideration.

Winter running here in central Idaho will likely include either running on cleared bike pathways or on snow covered trails used mainly by hikers. The hiking tails are much more pleasant and since there is a strong contingent of local winter hikers, numerous trails are “tramped” in throughout the season. Given the large proportion of sunny winter days in Sun Valley, quite a layer of ice can build up on the trails due to freeze-thaw cycles and I found last year that a shoe like the Salomon Spikecross ( a shoe similar to the Snowcross but without the integral gaiter) is necessary for comfortable, non-slip running, particularly on the ups and the steeper downs. The other factor that plays in here is the performance of a shoe when there is newly fallen snow on an otherwise “tramped” trail. In this instance, having protection from snow getting into the shoe is critical to ensuring a pleasant running experience. Last year, using the Spikecross, I could not comfortably run in anything greater than about 2″ of fresh snow due to snow getting inside the shoe. This really limited my runs. All of this is taken care of by the Snowcross.

The upper and the water-resistant zipper-closed integral gaiter are designed very much like a Salomon Nordic ski boot with a major difference being the materials used. The Nordic boots are made with essentially unbreathable fabrics and some rigid structure, whereas the Snowcross utilizes breathable “Clima Shield” ( a Gore-Tex-like membrane material) fabrics and thin laminated overlays for structure. The padded tongue which lays under the speedlaces and the outer gaiter provides for a very comfortable fit. The fit is snug but no too much so.

The padded tongue makes the shoe very comfortable and draws design elements from the Salomon Nordic skiing boot technology.

Another view of the integral tongue.

Looking down into the shoe showing the position of the tongue, speedlaces, and upper zip closing gaiter. Note also the grip strap at the back of the foot, making it easy to put the shoe on.

The first picture above also shows the ankle protection areas- a very welcome feature given that any “punch-through” on snow covered trails will lead to some level of ankle impact. These scuff guards will help with this issue, but we will have to see how they perform as they are not particularly substantial.


The gaiter and the associated constructions do not add much weight as this US 7.5 size weighs in at 337 gms (11.9 oz). This is to be compared to an equivalent size Speedcross 3 weighing 310 gms (10.9 oz). So 27 gms for a complete gaiter and tongue construction is well worth it given the protection and comfort that is provided. And, of course, winter running, for me anyway, is about maintenance and comfort, not speed. However, the Snowcross is still in the “light” category for trail running shoes.


As mentioned above, the fit is snug but no too much so. When you first put them on they definitely feel like a boot but after a short run they truly feel like a running shoe and perform as such. The “sensifit” design does a good job of wrapping your entire foot and keeping it in place. This is important because the gaiter system is putting a bit more torque on the lower foot and movement could be an issue. I found no excess movement to be apparent and I did not find the gaiter to be the least bit confining.

The upper is surprisingly flexible and soft and there is no “bunching-up” of material that could potentially lead to hot spots. Overall a very comfortable fit.


A big part of the performance of this shoe is the outsole. It is made of a non-marking polymer with deep lugs and nine (9) carbide spikes (similar to the Spikecross). The lug pattern is very open and has, so far, shown good mud release.

Aggressive, deep lugs and nine (9) tungsten carbide spikes makes the outsole of this shoe up to the task of winter running.

I have had these shoes on snow-covered tramped and un-tramped trails (through about 4-6″ of fresh fallen snow) , relatively steep uphills and downs (about 18-20% grades), ice conditions, rolling terrain, and black ice conditions on a bike pathway. They performed outstandingly in all conditions, so much so you can get a bit over confident and begin to test the boundaries of their abilities.

Running Impressions

I have never run in winter conditions with so much confidence in the past. I dealt with either not enough grip or not enough protection from snow getting into the shoe and this shoe solves both of these issues. Once you run in the Snowcross for a few miles it truly feels like a running shoe and you go into the snow covered trails with relative abandon. It is truly liberating and I am looking forward to a consistent winter of regular runs.

With respect to the higher, 9 mm drop of this shoe, I can definitely feel the heel striking (and getting in the way) much more than in the the Sense or the Fellcross. This is unfortunate as I think a low drop winter version of the Sense or the Fellcross would be quite desirable to the growing number of low drop runners out there. Perhaps such will emerge in the future, but in the meantime the Snowcross is a good substitute.


Another $200 shoe from Salomon…. is this a trend? Are we recalibrating to a “new normal” for running shoe pricing? Perhaps, but I must say that all of the integrated technology in this shoe and the very nice fit are reasons to think that the price is not too out of line. It is still expensive though…. but no where near as expensive as Nordic skiing!

Bottom Line

Run with confidence on snow and ice covered trails…. let the winter begin!!

I will update this review as I accumulate more distance, but at this point I can highly recommend this shoe for winter running.

Update 7 November 2013

As supported in the comments  on this post, I will note that the ‘CS’ part of the Snowcross CS shoe refers to the material used on the upper construction. It is supposed to be ‘water resistant’. My experience is that after just a few runs it is no longer water resistant and if conditions are wet your feet will be wet. A much better choice for the upper material is Gore-Tex, as is seen in numerous competitive winter running shoes. It is unfortunate that Salomon have not updated the 2013 model with a Gore-Tex upper and I can no longer recommend this shoe for winter running unless the conditions are dry.

I also think that Salomon have missed the opportunity to offer a low drop winter running shoe for the 13/14 season…. perhaps we might see this in 14/15? In any case if you run in low drop I suggest you seek out a low drop winter shoe alternative to the Snowcross CS.

Update 15 November 2014

I have “modified” my Snowcross after giving up on Salomon to offer a low drop winter running shoe with studs for 2014/2015. You can read the post about the modifications here.

Salomon S Lab Sense Review – Final Update

Prior posts on the performance of this shoe have detailed:

I have now taken a pair of Sense to their end of life (EOL).

After about 1200 km (700 miles) the shoes are just now showing evidence of breakdown- peeling of the outsole, diminished cushioning, and lug wear. Although still suitable for road running (as a racing flat), their use on trails has come to an end. This is mainly because the peeling outsole presents a potential tripping hazard, which, at my age, is something worth avoiding. Secondarily, the diminished cushioning is resulting in skeletal wear otherwise not previously apparent on longer (35+ km (20+ miles)) runs. They are still fine on shorter runs as far as I can tell.

Salomon S Lab Sense after about 1200 km. As you can see we have had our first snow here in central Idaho. The last run for these shoes was in the snow where they performed well even with significant wear of the lugs. The snow also cleaned them up- just in time for pictures.

Right sole- note that the lug depth is still reasonable, about 30-40% worn. Also note excessive wear on outside of the sole at the rear- this is due primarily to breaking on steep downs. Perhaps when my technique improves this will be less evident.

Left sole. Similar wear but still quite stable. Note the hole in the EVA midsole material to the rear of the arch. This was a sharp wood splinter that never made its way into the shoe.

Peeling left outsole… and the primary reason these shoes are being retired. I do not have confidence that gluing will work or be reliable. No tripping for me.

Peeling right outsole. Not as significant as on the left but the peeling is well along.

View from the top after about 1200 km. Uppers are entirely intact and show no signs of failure, other than the initial minor delamination of the exo-skin that occurred within the first 150 km of use.

I must say that I am pleasantly surprised with how durable and comfortable these shoes have been. With initial reports indicating that they should likely last only about 500 km (300 miles), getting in excess of 1200 km (700 miles) out of this pair is reassuring and clearly justifies the price just based on durability, let alone the excellent on-trail performance documented in earlier posts. I should think that I could get perhaps even more use if I was able to securely re-glue the outsole back to the last- at least for shorter runs. The uppers remain entirely intact with no signs of failing any time soon.

Every time I ran in these shoes as part of a rotation with the Fellcross, I ran about 15-30 seconds faster per km. Not sure why, but certainly the light weight plays a role, however I think that the endofit and the low profile (both from the thickness of the midsole and the height of the lugs) just make me a more efficient forefoot striker.

Salomon S Lab Sense Ultra

Salomon have, this past summer, introduced the Salomon S Lab Sense Ultra- a slightly “beefed-up” version of the Sense. According to reports, the shoe incorporates a bit more rock protection with a thicker “Profeel” film element and a bit more cushioning and traction with deeper lugs (and perhaps a bit more wear). The shoe is slightly heavier, although it is still very light at about 200-210 gms (7-7.5 oz) depending on size. I look forward to this shoe as I think that it will perform better for longer runs and races where the Sense may not provide enough cushion for some runners. Here is a short video of the Sense Ultra:

Bottom Line

Well, I have taken the Salomon S Lab Sense from the box to retirement including about 1200 km of running on trails in the Rocky Mountains, racing in two ultramarathons, and used in virtually all expected conditions. The shoes have performed at the highest level in all respects except in the area of cushioning. I confidently recommend the shoes for mountain trail ultramarathon running training and for shorter (<70 km) ultramarathon races. If the S Lab Sense Ultra provides more cushion it may be the right balance between weight and performance. Stay tuned.

Training Effect – analysis and use of the Garmin 610 watch- update

I wrote an initial post on this subject a few months ago and have continued using the analysis protocol described therein. This protocol uses a metric derived from the measured training effect (as calculated by the Firstbeat algorithm included in the Garmin 610 (and 910) watches) by multiplying by the training session duration in minutes. Herein this metric is referred to as intensity-minutes. This metric is very valuable as it quantitatively captures the effort expended during the training session. The nice part of this approach is that the watch can reliably record and calculate the training effect without potential mis-perception of your perceived effort. Of course you must ensure that the basis data (your heart rate zones) that you provide to the Firstbeat algorithm is accurate. I continue to find both the calculated training effect and the intensity minutes to be an accurate description of the training sessions.

In the meantime I have done a bit more reading to justify the multiplicative functionality of the the two inputs (training effect and session time) and found support for this from a physiological basis (in Dr. T Noakes treatise, The Lore of Running). In addition, I recently came upon a fully developed literature on the use of this very same metric for use in training for endurance (and other) athletes.

TRIMP (Training Impuse)

It was surprising to discover that the approach that I naively developed, i.e the use of “intensity minutes” (training effect times duration of session) as a fundamental metric of a training session, was first proposed in 1975 (1) and has been in use in numerous forms ever since. The authors refer to the metric as Training Impulse, or TRIMP. This method appears to be quite robust and is best illustrated by a recent study (2) of three elite marathon runners leading up to the London Olympics where TRIMP is used as a basic training monitoring tool. A review and commentary of the data in this study is here.

The aforementioned recent study used a perceived effort scale called the Borg Scale:

6  No exertion at all
7.5 Extremely light
9  Very light
11  Light
13  Somewhat hard
15  Hard (heavy)
17  Very hard
19  Extremely hard
20  Maximal exertion

Although a reasonably divided scale, with the Borg Scale I would find it difficult to be repeatable and reliable with the various sorts of training sessions I partake in. I have found that a primary issue with the perceived effort approach in capturing training effect is that it is not generally a reliable indicator of actual effort. In contrast, upon analysis of the time series heart rate data as compared to the calculated training effect, I have found the Firstbeat firmware to be quite accurate, even at short (ca. 3 minute) duration. Given that the calculation is a direct output of every training session, it is convenient as well. In addition, since the Firstbeat training effect scale ranges from 1.0 to 5.0, this allows for 40 levels of calculated effort, a much finer scale than the Borg Scale.

Given the issues associated with structured training sessions (e.g. intervals, fartlek, etc.) and the common use of average HR for estimations of perceived effort, other approaches have been developed to overcome shortcomings and they are nicely summarized in the following three articles/posts:

  1. Training Schedules
  2. TRIMP
  3. Adjusted TRIMP

With respect to using the training effect calculation provided by the Garmin 610 via the Firstbeat firmware embedded in the watch, I have found that I can accurately capture the true effort expended in short (3-10 minute) intervals by saving each interval as a separate event. This way each part of the interval workout (w/u, individual intervals, and c/d) can be separately recorded and TRIMP values (or “intensity minute” values) can be calculated individually. These calculations are then just additive for the total “intensity minutes” of the training session. Given that the Firstbeat firmware is also analyzing HR recovery rate (in addition to time series HR and duration), i.e. a direct measurement of the training load on your system, the calculated TE, in my experience, is very sensitive to the transient and cumulative training load. For instance I have found in interval sessions of 5 X 7 minute hill repeats (both in running and in Nordic skiing) that the calculated TE for each of the 5 repeats shows typically as follows: e.g. TE= 4.8, 4.7, 5.0, 5.0, 5.0. As you can see the first two repeats are typically slightly low but as I work into the sessions the desired maximal effect is evident. I have found such accurate measures at interval segment times as short as 3 minutes.

As far as specific strength sessions with weights, I find the calculated TE is a bit low based on my perceived effort, but this actually may be accurate as outlined above, as perceived effort can be an unreliable measure- i.e. a workout may seem hard but is analytically not. I prefer specific strength sessions that replicate the actual whole body motion of the particular sport, for instance e.g. double pole rollerski sessions for nordic skiing or hill repeats for running. I find that such whole body motions are much more focused on correctly developing the correct muscle systems for the activity. The TE value can then be reliably derived from the watch algorithm.

Training Analysis Update

Since I last posted on this subject in mid-May 2012, I have attempted to use the intensity minute metric to plan and monitor a structured training program over the past five months. This period also included two ultramarathon races (53 km/7,000 vert and 70 km/11,200 vert) and preparation for a third ultramarathon (84 km/9,600 vert) which I did not do due to fires and the associated smoke at the race site.

What seems to be working for my monitoring purposes is time series graphs of 7-day total, 7-day average, and daily measures of :

  1. intensity minutes
  2. vertical ascention
  3. miles
  4. time

Plotted below is the intensity minute data:

These data include only the running sessions. During this period I am also doing ski-specific sessions which are primarily double pole roller skiing for an average of about 3-6 hours per week.

The training structure is fairly obvious, but here is a narrative:

  • from mid-April to mid-May- developing base aerobic training with a couple of progressions and a bout of Achilles tendonitis
  • a build up to about 17 June for a 53km race with about 7,000 feet of vertical on 23 June
  • a week of taper and then the race
  • a recovery period (about 3 days)
  • another build up to about 7 July for a 70 km race with about 11,000 feet of vertical on 14 July
  • a week of taper and then the race
  • a recovery period (about 2 days) and about 2 weeks of lower volume
  • a third build up to about 11 August for a 84 km race with about 10,000 feet of vertical on 1 September which was truncated because I decided not to do the race due to fires and associated smoke
  • a volume block from about 20 August until about 5 October
  • a recovery period of about 7 days
  • transition to ski-specific training (some running but more roller skiing and hill bounding)

As far as the effectiveness of this training periodization, I placed in the top ten overall (5th and 9th) in each race. A better evaluation is that in each race a nationally ranked runner participated (and won) so I can calibrate my performance on a more national level. I was within 20% of the winning time in both races, which, given that these are my first two ultramarathon races, that I have been training for ultramarathons since April 2012, and that I am old (56) it would seem that the training protocol is at least passable. I have a lot of skill development and lateral muscle building to do, but this is a good start. My only thought is that I would add more long (20+ miles) runs into the program. You can see that I have started to do this. Time will tell if it will have any positive effect; I expect that more longer runs will help with having a strong finish. I also need to concentrate on the climbing as I was in the early part of this training period.

Plotted below are the vertical ascention, distance, and time data for the same period:

Concluding Remarks

I have found that the Firstbeat training effect calculation that is embedded in the firmware of the Garmin 610 (and 910) watch is reliable and very useful from training monitoring and training periodization perspectives. So long as one takes the time to accurately determine their heart rate zones, the calculation has been very consistent and in agreement with expected perceived effort.

Further review of the literature has validated the use of the “intensity-minute” metric (or TRIMP, as accepted by professionals in the field) as presented here. Some care needs to be taken to properly capture all aspects of structured training sessions, particularly interval sessions. But with intelligent application and diligent recording of the data, a periodized training plan can be based on “intensity minutes” and reliably executed upon. In addition, appropriate modifications can be made within a given training period based on the intensity minute data to allow one to get the most out of their training time commitment.

I highly recommend that consideration of this approach be a part of your training planning.

8 Feb 2013 update: I have posted a complete analysis of my entire training year (both running and skiing seasons) utilizing the protocol described above here.

1. E. Banister et al., “A systems model of training for athletic performance”, Australian Journal of Sports Medicine, 7:57-61, 1975.

2. T. Stellingwerff, “Case study: nutrition and training periodization in three elite marathon runners”, International Jouranl of Sports Nutrition and Exercise Metabolism, 5:392-400 (2012).