Salomon socks have been something of an enigma in the US. Although broadly available in Europe, the sock lines have had very limited distribution in the US. This seems to be the result of the fact that Salomon don’t actually own the rights to distribution of their socks- this was sold to Intersock Group (ITA) in 2002 . For a while Interlock Group had a US affiliate in Portland, OR that offered a very limited selection of Salomon socks through a rudimentary online shop and to some retail outlets. This selection included only a few of the running socks. Having been introduced to the full line of excellent Salomon socks whilst in Europe many years ago, I sought out a source here in the US- sometimes the Intersock Group affiliate would have the socks available online but often there was limited stock or certain models were not brought in to the US. So in past years, when in Europe I would pick up a few pair of socks. It was a non-ideal situation, particularly when the socks started wearing out.
But there seems to be movement on availability of Salomon socks in the US. A new Intersock Group affiliate (Sport Dispatch) has picked up the line and they are bringing in an expanded line of Salomon socks to the US market, including running, alpine, and nordic socks. I was contacted and offered samples for testing and agreed to accept the samples. This post is a review of the S Lab NSO line of Salomon trail running socks- it’s their top-line offering and includes quite a bit of technology. After extensive use of the NSO samples I subsequently purchased six pair of one of the NSO variants, so although I did accept samples, I personally purchased the product because I liked it.
My past use has included three models of Salomon socks, the most recent being a very minimalist sock called the “Sense” sock. It was introduced in 2015 or so and I have been using it since. I bought six pairs and they have only this past season begun wearing out (at the heel counter and in the heel base). That’s four full mountain running seasons of wear and tear and represents excellent durability. The performance was outstanding as the socks provided sufficient protection yet were thin enough to not be intrusive and they dried out very quickly. I had similar experience with prior versions of Salomon socks and have found them to be among the best offerings at any given time.
I am not convinced that a running sock should provide padding and these “Sense” socks provided no padding. I prefer to let my selected shoe provide whatever cushioning I need- the cushioning is where it needs to be and is stable and not potentially moving around or changing fit levels. This is just my preference as I know many runners are convinced that their highly cushioned socks are an important part of their comfort and performance. The following review of the Salomon S Lab NSO socks will be colored by this preference of minimal cushioning.
Salomon S Lab NSO Sock line
Salomon have chosen to divide the S Lab NSO running sock line into three variants- Short Run, Mid Run, and Long Run. The socks have increasing levels of features and technology as the intended use as a function of run length is increased. I’ll review the included technologies and features for each variant but will start with an overview. There is also an NSO compression sock (NSO Leg Up) that I will mention at the end of this post. The “science” (such that it is) is undecided on the efficacy of compression for recovery and/or support in running and I’ll address that later.
nso sock technologies
The “NSO” in the S Lab NSO “Short run”, “Mid run”, “Long run”, and “Leg Up” sock designations refers to the “enso” Zen Buddhist single-stroke calligraphy of a circle. Enso drawings are a part of meditative practice and take many meanings including “harmonious cooperation”, which is the intended meaning put forth by Salomon. More on the “cooperation” aspect below.
Salomon works with their athletes and Intersock Group to design and manufacture the sock lines. This involves interaction of the most demanding users (elite athletes) with the experienced Salomon designers and the sock technology experts at Intersock Group.
The primary new technology offered by the NSO line is based on oxide particle infusion of fabrics. Fabrics with appropriate composition oxide particles are claimed to provide far infrared radiation reflection and emission*. In Salomon’s words- naturally generated heat (including far infrared wavelengths) from the body interacts with the oxide particles in the fabric to “activate and reflect this energy, enhancing muscle tone, recovery, and balance”. Wow, that’s a lot of function from some oxide particles! But let’s back up and look into the proposed basis for this technology.
Photobiomodulation (PBM) is process in which low levels (fluences) of light energy are utilized to interact in a positive way with human tissue. PBM (also known as Low- Level Laser Therapy (LLLT)) has found utility in treating medical conditions including hearing loss, foot tendinopathy, diabetes, cardiac conditions, and cancer. PMB is increasingly being accepted as a promising treatment therapy. That, of course, as in any “medical science” claim, does not mean that the therapy is efficacious. It may just mean that a new experimental therapy which has a large placebo effect can be easily made into a profit center. Such is medicine today.
The applications of PBM for athletic endeavor include the use of such treatments to assist in dilation of vascular tissue. Specifically it has been found that nitric oxide synthase (NOS) (an enzyme) participates in numerous biological processes by enabling the in-situ production of NO (nitric oxide) within tissue. NO is claimed to be critical to regulating something called vascular tone. Vascular tone is the degree of constriction of vascular tissue. NO production is associated with vasodilation and therefore promotion of the formation of NO is viewed as being a positive outcome for athletic activity.
NO production is also claimed to be critical to general athletic performance. As usual, the many claims are not well supported (or even supported at all) but you can do your own background reading and decide independently. Beware anything scientific being written by MDs- they are not scientists.
Further, it has also been claimed that NOS production (and therefore NO) is enhanced by radiation of human tissue with far infrared (FIR) wavelengths (about 5 microns-1000 microns (1 mm)). This is a wavelength region situated between mid infrared/near infrared (MIR/NIR) and visible light on the short wavelength end and microwaves on the long wavelength side. Infrared radiation has colloquially been referred to as “heat waves” since this radiation, which is invisible to the human eye, can heat a substance that is comprised of molecules that can oscillate under the influence of the radiation. The molecule movement produces internal friction that results in heat.
For FIR irradiation, water and human tissue are found to be excited by these wavelengths and it is proposed that this excitation can lead to both internal heat generation and enhanced production of NOS and therefore NO. Inference and some observational data indicate that reduced vascular restriction can result from FIR irradiation. FIR, at appropriate intensity, is experienced by the human body as a gentle heat which is a direct result of the interaction of this radiation with human tissue.
OK, so much for NOS and NO (and not to be confused with NSO!…).
Now, it is well known that certain inorganic materials and certain polymers can efficiently reflect and/or emit FIR wavelengths when irradiated with equal or higher energy rays (i.e. FIR wavelengths and shorter). The inorganic materials most prominently used for FIR reflection/emission are primarily mineral oxide compounds such as tourmaline (a naturally occurring borosilicate compound). Fabric manufacturers have been developing products that contain nano-sized particulates of these FIR reflector/emitter compounds. It is asserted that the FIR radiation that naturally emanates from the human body is reflected back into the body and that this can promote increases in NOS and, therefore, NO and, therefore, decreased vascular restriction. Obviously, athletic clothing has been a primary focus for the fabric manufacturers since keeping blood flowing will have only positive effects for both performance and recovery. This proposed effect is also where Salomon have used the “enso” (NSO) connection- the body’s natural generation of FIR is reflected back by the oxide particles and assists in vasodilation via a synergistic, “enso”-like, “harmonious cooperation” process.
There exists scant data that supports any measurable efficacy of the use such FIR reflecting particle-infused clothing in athletic endeavor. There are, however, more reliable, although not conclusive, data for other applications of the use of FIR for treating certain medical conditions (e.g. lymphedema) that have been interpreted as being the result of FIR-induced vasodilation via the NOS-NO pathway. So there is promise but no clarity at the moment on application in athletics.
Lack of data has never stopped marketeers (or “woo-woo” medical practitioners), particularly when what is being marketed involves increased human comfort or, in the case of athletics, increased performance or recovery. And that is where we are today with the use of inorganic particulates in athletic clothing- an essentially made-up advantage (that may or may not end up being real) with manufacturers claiming efficacy and users claiming positive benefits- all without supporting data. Of course we should not ignore the reality of large placebo effects that may be at play as well.
Back to the S Lab NSO socks. What Salomon have done is to include mineral oxide infused fabric in the sock to promote vasodilation in and around the foot and ankle. Feet and ankles, as all runners know, are (and excuse the pun) the Achilles heel of running since all propulsion is centered around the foot and any issue with ones feet (including the Achilles) will very adversely affect ones running. Having strong, high performing, and quickly recovering feet and ankles is critical to being able to train and perform at our best. Salomon are proposing that these socks with FIR reflecting mineral particle infused fabrics will improve our running performance and allow for quicker recovery. Perhaps this is true, but perhaps not, and only further data, analysis, and mechanistic scientific work will give us answers. In the meantime it probably does not hurt to try the technology, make personal observations, and come to some position on the subject. It is claimed that the nano-particles are inhert to the body and serve only to emit/reflect FIR radiation into the body, so there appear to be no downsides to trying these fabrics out. There is, however, the overriding concern about physical absorption of nano-particles into the body and bloodstream and any possible adverse health effects due to absorption of these particles in either short or long term. Something to think about but I’m in the camp that provided the sock performs well as a sock, having some other potential feature that may assist in performance and recovery is a positive thing and worthy of trying out. You can make your own determination.
SAlomon S Lab NSO sock line details
As noted above Salomon is offering the NSO sock line in three variants, each focused on different run “lengths”- short run, mid run, and long run. The primary differences are in the level of cushioning and compression offered by each variant with the highest amount of cushioning and compression being in the long run sock. All of these socks are designed enanitiomorpically, i.e. the socks pairs have a left and right. But there are other differences as well and I will review them here.
Nso short run
The Short Run variant of the NSO sock is a minimalist sock that provides a thin layer of cushioning at the heel and toe and thin or super thin materials everywhere else. For those that like a minimalist sock (as I do), this version of NSO line will likely be appealing.
This model has the least amount of technologies in the NSO line but does include the oxide particle fiber material (Quantum Energy). The other features of this sock are extreme thin-ness in the mid-foot and ankle area and represents one of the most minimal of socks out there for trail running.
Minimalist socks are my preference and the NSO Short Run is an outstanding minimalist offering. They are very lightweight and have a skin-fit with flat seams. The heel and forefoot cushioning is noticeable but not annoying. The silicone “stripes” intended to keep the foot from moving within the shoe seems a bit unnecessary. It is my position that the fit of the shoe is what will take care of that — buy a properly fitted shoe and there will be very little movement within the shoe. Another reviewer of the Salomon NSO sock line** thought highly of the silicone “stripes” as they could make a badly fitting shoe work better. Well, why run in a badly fitting shoe? Particularly if you are using Salomon shoes with EndoFit, SensiFit and the other “fit” technologies that make Salomon the superior shoe for fit. Let the shoe do what it is supposed to do and do not depend on a sock to fix a badly fitting shoe. The “grip stripes” are present in all three variants of the NSO sock line and the comments above apply to all the variants.
The “short run” sock has performed very well in a wide range of conditions from early spring wet and snow to super dry and “moondust” summer conditions. They dry quickly, are transparently comfortable, breathe exceedingly well, and do a good job of keeping tiny dust particles in dry conditions away from the foot. The sock is very thin in certain areas (e.g. across the middle of the foot where shoes are generally cinched down). This eliminates any concern with thick, bunched up, fabric in this critical area. As a result the socks essentially disappear and just do the job of protecting your feet from abrasion and dust. Is the NSO technology doing anything? I don’t know. I do know that these socks are a great choice for those who like a minimal sock. This is my current go-to sock and , as indicated above I bought six pair of this “short run” variant for daily use.
NSO Mid Run
The Mid Run variant in the NSO line adds a bit more cushioning throughout the sole and mid-foot of the sock whilst maintaining all of the technologies in the “short run” model. This variant also includes something called Nano-Glide, a polyamide coating on the fibers that minimizes friction between skin and the sock. The Nano-Glide technology has been used in Salomon socks for at least 7 years and I can attest to it’s efficacy. I have never had a blister, hot spot, or even a red spot while using socks with the Nano-Glide fiber coating. My only gripe- Nano-Glide socks can be difficult to slide through certain tights. It is apparent that the materials that some Salomon tights are composed of “catch” the Nano-Glide coating and make it difficult to get your foot through when putting on the tights. I’ve noticed that the latest Salomon tights that I have do not exhibit this issue.
There is also a limited amount of compression in the mid-forefoot area and around the lower part of the ankle. Based on available evidence in many studies, compression shows no reliable efficacy but there may be a significant placebo effect. So although there may be no real performance advantage, you might “feel” better with compression and, to be honest, that is what matters particularly in long runs and races. I do not have this placebo effect so compression is not something that I look for, in fact I find it to be annoying in some cases. But — to each their own!
This is still a very lightweight sock and can be viewed as the Short Run with the anti-friction NanoGlide technology and a small bit of compression mixed in. I find the fit to be excellent and the cushioning unobtrusive. They dry very quickly and provide high performance for the basic purpose of a sock- protecting your feet from abrasion and dust. The Short Run variant is my daily-use sock but the Mid Run is often in the mix and it is hard to tell the difference between the two when running. So if you like a bit more cushion the Mid Run might be an option.
NSO Long Run
The Long Run variant is the sock that Salomon designed specifically for Francois D’Haene, the long distance specialist on the Salomon team. I’ve seen pictures of the Salomon designers/engineers working with D’Haene on these sock and concentrating on features in and around the ankle. As anyone who has run a 100 km+ race will know, ankle protection and comfort is critical to an enjoyable day and it apparent that Francois is particularly interested in this.
The Long Run variant is basically a Mid Run with a lot more compression throughout the mid foot and ankle area. The sole, heel, and toe of the sock is virtually indistinguishable from the Mid Run including the NanoGlide polyamide coating technology. The Long Run has a couple of other features: a padded area at the medial malleolus (the knobby ankle bone) and a directional knit structure in the lateral ankle area. I understand the padding since, as when one gets tired, it is common for the medial malleolus to get “scuffed” by the opposing foot as it comes by on the run stride. You’ll see this after a run or race where scuff marks are evident in this area. In long runs and races this can lead to abrasion and pain so putting a bit a padding there makes sense. The directional knitting on the other hand seems superfluous. It falls in the same category as KT tape- useless. There is no reliable evidence that such minuscule directional tension does anything efficacious. But again, there may be a significant placebo effect so some may “feel” a difference.
The Long Run variant is a bit more of a chore to get on due the compression knit but once on it is very comfortable. Even with all of the added features it is still on the minimalist side of trail socks currently available. I find the fit to be excellent and the comfort is great. It is maybe a bit too much sock for me but I did run in this sock for a 30 km mountain race with about 1500 m (5000 ft) of climb and descent. The sock performed well and essentially disappeared- meaning that I had no thoughts about socks during the race which is exactly what one wants. I thought that a bit of extra cushioning might be desirable for a race that started out with a 6 km (4 mi) 750 m (2500 ft) climb followed by a 5 km (3 mi) 500 m (1500 ft) descent. Perhaps there was an advantage but the difference I felt was minor if at all.
As with all Salomon S Lab products, these sock are expensive at $28-$30 a pair, depending on the variant. But they do provide a lot of technology and some unique features all while maintaining a lightweight, minimalist ethos. Also, if the socks are as durable as other Salomon socks have been in the past, you will be using these for years and the price point then looks a bit better.
A high technology line of high performance socks that will appeal to many trail runners, independent of specialization — from technical trail aficionados to long distance grinders. Does NSO do anything? Who knows but as with any new technology time will tell. In the meantime, the Salomon NSO line of socks offer a minimalist solution for whatever “style” of trail running you might partake in- all with excellent fit, protection, and support. And they all dry very quickly. For me it all comes down to whether or not a sock “disappears” when I use it. These do and I expect to be training and racing in these socks for years to come.
As indicated at the outset, thee NSO line includes a “Leg Up” variant that is a full knee height compression sock. Although I have tried this sock out, I personally find the compression to serve no purpose other than to be annoying. So I provide no full review here. There are many others that find compression to be functional and I encourage those that do to check out the “Leg Up” NSO variant. If there is any model in this line where the NSO technology is likely to be apparent it will be in the “Leg Up” where the NSO fiber material is covering toe to knee and any FIR effect that is extant should be maximized.
**Note: a couple of the pictures of the socks in that review are incorrectly correlated with the sock type- specifically they show the NSO Short Run as the Speed Support and the Speed Support as the NSO Short Run.