What do nutritional supplements, training tech, and athletic gear have in common? They all fit into the trend of "optimizing" your athletic performance. These days, everyone wants to get more benefits from less work. So, it can be easy to dismiss products that make bold claims about how they'll improve your workouts. You might assume that such products represent a passing fad. After all, there's no workout pant, treadmill, or vitamin that's going to magically transform you in LeBron James or Maria Sharapova.
As you try to separate fact from fiction, I recommend turning to the scientific literature. Answer the question, "What experiments support these claims?" and you'll be a lot closer to knowing which trendy workout products are worth your money and attention.
We've combed through tons of advertisements for athletic socks. Since many brands make bold promises, I want to help you differentiate between the truth and the hype. What can socks do, and what is beyond the scope of a sock, no matter how great it may be? For each claim below, I've marked whether it's a "myth" or "reality". For the true benefits, I've provided scientific evidence to bolster the claim.
They Promote Healthy Blood Flow: Reality
Compression socks have been shown to promote blood flow, which may have a positive impact on performance. Not only do compression socks improve circulation in the legs, but they also increase healthy blood circulation in the upper body as well. A 2016 study published in The Journal of Spinal Cord Medicine tracked the performance of ten male wheelchair rugby athletes with cervical spinal cord injuries. Researchers asked the athletes to do wheelchair sprints and laps while wearing medical grade compression socks on both legs. Compared to the same exercises performed without compression, the use of compression socks improved both average lap time and upper limb blood flow post-exercise. (Vaile et al.) Although these results may seem counterintuitive—How does a sock improve your speed if your legs are paralyzed?—there is a physiological explanation for this outcome.
Compression sleeves, socks, and stockings all work by compressing the veins in your legs. This improves the velocity of blood flow in the area, improving your overall circulation. Graduated compression assists with venous return by pushing blood from the feet and lower legs towards the heart. Together, the compression and graduated pressure help ensure that blood doesn't stagnate in the lower legs. The faster blood flow doesn't just impact your circulatory system in your legs; the whole body benefits from faster, more efficient blood flow.
They Eliminate Blisters: Myth
Although some socks claim to completely eliminate blisters, the best you can hope for is a reduced incidence of blisters. Socks do this through several different mechanisms. First, graduated compression socks have been proven to reduce edema (swelling) in the feet and legs. (Lim E392) When your foot doesn't swell during or after exercise, you experience less friction between your foot and your shoe. Also, a sock can be manufactured out of moisture-wicking material that keeps your feet dry. Since sweaty feet may contribute to additional blisters, eliminating moisture can help reduce the total number of blisters you experience. Lastly, extra padding may help to prevent blisters. Unfortunately, no socks can completely eliminate your risk of blisters, especially since your shoes also contribute to blister formation. If you hope to avoid blisters entirely, you should pair compression socks with comfortable shoes and some other techniques, such as building calluses over time or bandaging blister-prone areas.
They Promote Faster Recovery: Reality
Several studies have shown that graduated compression can improve functional recovery for athletes. For example, a 2012 study in the Journal of Strength and Conditioning Research looked at the effect of wearing graduated compression garments during recovery. After performing a 40-km cycling trial in normal cycling gear, the test subjects wore graduated compression garments continuously for 24 hours. After the recovery period, they participated in another 40-km trial. After wearing compression garments (as opposed to control garments), the subjects showed significant improvements in both average power output and performance time. (de Glanville Abstract) This study suggests that wearing compression during recovery periods may lead to stronger athletic performance in subsequent activities.
Furthermore, wearing compression garments during recovery could make the best use of your recovery time. Another study, done in Australia in 2015, reinforces this hypothesis. The study evaluated pre-marathon and post-marathon treadmill tests, performed 2 weeks before and 2 weeks after a marathon. Notably, the time score decreased for the placebo group, whereas the compression group significantly improved upon their pre-marathon scores. Compared to the placebo group, the group wearing graduated compression socks during the 48-hour period after a marathon saw a 5.9% improvement in time to exhaustion. (Armstrong Abstract) Even if compression is only worn in the period immediately following strenuous exercise, this study suggests that the impact can improve performance two weeks later.
These studies suggest that graduated compression garments may optimize recovery time for both cyclists and runners. A number of other studies show similar outcomes for different sports (Higgins, Kraemer).
They Improve Your Sprint Time: Myth
It appears that the benefits of compression may be cumulative. The studies mentioned above do not investigate the influence of compression on a one-time athletic performance. Instead, they focus on the impact of compression gear worn during recovery and during repetitive actions. It's unlikely that compression will improve your performance during a single fast, non-repetitive activity, such as a sprint. In fact, experiments designed to evaluate compression garments worn during a single activity show mixed results (Beliard Key Points).
They Eliminate All Injuries: Myth
Some sports compression socks boast innovative materials, like wearable sensors and high-tensile strength fabric, and they promise to eliminate injuries. Common sense tells us that socks can only do so much when it comes to injury prevention. Running with good form may help to prevent shin splints. Wearing strong socks and shoes may stop you from cutting your feet on sharp terrain. Most importantly, compression may give you added stability at the ankle, supporting optimal movement of that joint. Unfortunately, there's no sock on the market that can completely eliminate the risk associated with breaking a leg, stepping on a nail, or even stubbing a toe.
They Prevent Medical Conditions: Reality
Ample scientific evidence exists to prove the effectiveness of graduated compression therapy, especially when it comes to chronic venous disorders. They're the first-line treatment for varicose veins and spider veins. Most doctors recommend that postoperative patients and pregnant women wear them to prevent deep vein thrombosis (DVT). DVT becomes particularly dangerous in cases where a blood clot breaks off and moves to other parts of the body, causing an embolism.
For example, a pulmonary embolism occurs when a blood clot breaks off from a deep vein, travels through the bloodstream, and blocks an artery in the lung. Pulmonary embolisms can be fatal, so avoiding DVT is an important way to prevent life-threatening blockages. Although athletes tend to be in good health, they are not immune to life-threatening pulmonary embolisms or venous disorders. In fact, in an article published in The Journal of Emergency Medicine, doctors discuss the case of a athlete who became more vulnerable to DVT as a result of her participation in an ironman triathlon, explaining, "The diagnosis of DVT should be considered in any athlete presenting with leg pain, especially after a strenuous athletic event." (Tao Abstract) In addition to the benefits of compression socks related to athletic performance, the medical benefits to vascular health should not be underestimated.
They Clear Lactic Acid and Other Waste Fluids: Reality
Most athletes understand lactic acid on a visceral level because they've felt it. At a certain point in your workout, you may begin to feel less muscle efficiency and an uncomfortable burning sensation. In an article for Runner's World, Steve Magness explains,
At some point...you produce more lactate than you can clear from your bloodstream. When this happens, the hydrogen ions associated with producing lactate turn off the enzymes used to produce energy and may interfere with your uptake of calcium. As a result, your muscles' ability to contract is reduced and you're forced to slow. In other words, all the sensations commonly associated with "lactic acid" appear when you can no longer process lactate as quickly as you produce it.
Now, imagine that your leg muscles are releasing more lactate in your bloodstream than you can comfortably clear. Compression socks help you to move lactate around as efficiently as possible, leading to improved performance and increased comfort. Delayed-onset muscle soreness (DOMS) causes leg swelling and discomfort in the lower extremities but is unrelated to lactic acid. Instead, it's associated with a build up of other waste fluids, such as myoglobin and creatine kinase. Compression socks also help to rid the body of the waste fluids associated with muscle damage, by improving the velocity of deoxygenated blood back to the heart.
Scientific studies have shown that compression therapy can result in:
- A decrease in creatine kinase (Jakeman et al.)
- Lower lactate values during recovery (Berry and McMurray)
- A reduction in muscle pain, damage, and inflammation (Engel et al.)
- Improvement in variables related to endurance performance (Engel et al.)
Separating the Hype From the Science
A pair of high-end running shoes can't give you the running performance of Maurice Greene, and you're not going to instantly cut your marathon time in half with the right pair of running socks. That said, knee-high compression socks do offer unique medical and athletic benefits, supported by peer-reviewed scientific studies.
Graduated compression, in particular, has been shown to improve vascular health. With graduated compression therapy, you get a higher compression level at the ankle and lower compression at the calf muscle. This gradient assists the veins as they work against gravity, clearing waste and deoxygenated blood from the bloodstream. As a result, you might experience better circulation, fewer blisters, fewer stress injuries, reduced risk of venous disorders, and a more comfortable workout and recovery.
Armstrong, Stuart A., Till, Eloise S., Maloney, Stephen, & Harris, Gregory A. "Compression Socks and Functional Recovery Following Marathon Running." The Journal of Strength & Conditioning Research, Vol. 29, Iss. 2, 2015, pp. 528-533, https://journals.lww.com/nsca-jscr/Fulltext/2015/02000/Compression_Socks_and_Functional_Recovery.30.aspx.
Beliard, Samuel et al. “Compression Garments and Exercise: No Influence of Pressure Applied.” Journal of Sports Science & medicine, Vol. 14, Iss. 1, pp. 75-83, 1 Mar. 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306786/.
Berry M.J., McMurray R.G. "Effects of graduated compression stockings on blood lactate following an exhaustive bout of exercise." American Journal of Physical Medicine, Vol. 66, Iss. 3, 1987, pp. 121-132, https://europepmc.org/article/med/3605315.
de Glanville, Kieran M., and Michael J. Hamlin. “Positive effect of lower body compression garments on subsequent 40-kM cycling time trial performance.” Journal of Strength and Conditioning Research, vol. 26, iss. 2, 2012, pp. 480-486, https://pubmed.ncbi.nlm.nih.gov/22240553/.
Engel F.A., Holmberg H.C., Sperlich B. "Is There Evidence that Runners can Benefit from Wearing Compression Clothing?" Sports Med, vol. 46, iss. 12, 2016, pp. 939-952, https://www.researchgate.net/publication/301581402_Is_There_Evidence_that_Runners_can_Benefit_from_Wearing_Compression_Clothing.
Higgins, Trevor et al. “Effects of wearing compression garments on physiological and performance measures in a simulated game-specific circuit for netball.” Journal of science and medicine in sport, vol. 12, iss. 1, 2009, pp. 223-226, https://pubmed.ncbi.nlm.nih.gov/18078789/.
Jakeman, J.R., Byrne, C. & Eston, R.G. "Lower limb compression garment improves recovery from exercise-induced muscle damage in young, active females." Eur J Appl Physiol, Vol. 109, 2010, pp. 1137–1144, https://doi.org/10.1007/s00421-010-1464-0.
Kraemer, WJ, Bush, JA, Bauer, JA, Triplett-McBride, NT, Paxton, NJ, Clemson, A, Koziris, LP, Mangino, LC, Fry, AC, and Newton, RU. "Influence of compression garments on vertical jump performance in NCAA Division I volleyball players." Journal of Strength and Conditioning Research, vol.1, iss. 3, 1996, pp. 180-183, https://insights.ovid.com/strength-conditioning-research/jscr/1996/08/000/influence-compression-garments-vertical-jump/9/00124278.
Lim, Chung Sim and Alun H. Davies. “Graduated compression stockings.” CMAJ, Vol. 186, Iss. 10 pp. E391-E398. July 08, 2014, https://www.cmaj.ca/content/cmaj/186/10/E391.full.pdf.
Magness, Steve. "Workouts to Improve Lactate Clearing Rates." Runner's World, Hearst Magazine Media, Inc., 31 Mar. 2011, https://www.runnersworld.com/advanced/a20811165/workouts-to-improve-lactate-clearing-rates/.
Tao, Kevin, and Moira Davenport. “Deep venous thromboembolism in a triathlete.” The Journal of Emergency Medicine, Vol. 38, Iss. 3, 2010, pp. 351-353, https://pubmed.ncbi.nlm.nih.gov/19128915/.
Vaile, Joanna, Stefanovic, Brad & Askew, Christopher D. "Effect of lower limb compression on blood flow and performance in elite wheelchair rugby athletes." The Journal of Spinal Cord Medicine, vol. 39, iss. 2, 2016, pp. 206-211, https://www.tandfonline.com/doi/full/10.1179/2045772314Y.0000000287