By Marc Sorenson, EdD, Sunlight Institute
Almost no one realizes the dramatic improvement that sun exposure can make on athletic performance. I helped Dr. John Cannell obtain translations of many esoteric and decades-old studies that had been forgotten, probably due to the fact that sun lamps were used to create some of the improvements in athletics, and have fallen out of favor due to the sunscare movement. I co-authored a paper with Cannell, called Athletic Performance and Vitamin D.[1] That paper is the source of much of the material covered here, and it demonstrates the remarkable, positive effect of sun or other ultraviolet (UV) exposure on human performance. I would also strongly suggest that the readers avail themselves of Dr. Cannell’s book on the subject, called The Athlete’s Edge, which discusses in far greater detail the materials introduced here.
One of the salient studies on UV exposure took place in 1957 and assessed the influence of sun exposure on strength and performance over a two-year period.[2] During that time six subjects were able to increase athletic performance and muscle trainability through systematic UV exposure. But when vitamin D3 was used, it not only did not work, it inhibited the performance-enhancing effect of the UV. I sometimes fear the public is beginning to believe that if sun exposure is proven to enhance human health, one needs only to take a vitamin D pill. Don’t get pulled into that idea. Sun exposure will always be more important than any of the photoproducts whose production it stimulates.
Here are some of the other salient studies on sun exposure and performance. In 1938, Russian researchers demonstrated that a series of four UV treatments improved speed in the 100-meter dash compared to four non-irradiated students, when both groups were undergoing daily physical training.[3] The times improved from 13.51 seconds to 13.28 seconds in the non-irradiated group and from 13.63 to 12.62 seconds in the irradiated group. In other words, the UV-treated group improved by three-fourths of a second more than the non-UV group. That may seem like a relatively small improvement, but three-fourths of a second better time in a 100-meter dash could be the difference between first and last place!
German research from 1944 showed that the exposure of 32 medical students to UV, twice weekly during for six weeks, associated with a 13% improvement in endurance, whereas performance of a control group was unchanged.[4]
Other German research shows that the ability of a muscle to gain strength (trainability) is much better in summer than winter, and peaks in September.[5] In fact the trainability was 2½ higher that the average monthly trainability for the entire year.
Reaction time has also been shown to improve significantly in the sunnier months.[6] [7]
When we consider reaction time, muscle and bone strength, speed and endurance, we should realize that these measurements are not only important for athletes; they are important for all aspects of living for all people. Everyone wants to be stronger, quicker, and faster, as well as have more endurance in daily activities. So embrace the sun, but do it safely and do not burn.
[1] Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.
[2] E. Seidl and Th. Hettinger. The Effect of Vitamin D3 on the Strength and Performance of a Healthy Adult. International Journal Physiology, including Industrial Physiology, Vol. 16, Pages 365-372 (1957).
[3] Gorkin Z, Gorkin MJ, Teslenko NE. [The effect of ultraviolet irradiation upon training for 100m sprint.] Fiziol Zh USSR. 1938;25:695-701.
[4] Lehmann G, Mueller EA. [Ultraviolet irradiation and altitude fitness.] Luftfahrtmedizin. 1944;9:37-43. [Article in German].
[5] Hettinger T, Muller EA. Seasonal course of trainability of musculature. Int Z Angew Physiol. 1956;16(2):90-4.
[6] Sigmund, R. The effect of ultra-violet rays on the human reaction time. Strahlentherapie.1956;101(4):623-9.
[7] Seidl E. [The effect of ultraviolet irradiation on reaction time.] Int Z Angew Physiol. 1958;17(4):333-40.
By Marc Sorenson, EdD Sunlight Institute…
A most interesting research paper demonstrates that nitrate supplements, combined with exposure to sunlight, increases performance of cyclists.[1] The researchers state that “dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance.” And, as we have discussed in this blog, sun exposure reduces BP by increasing the production of NO. It was theorized that sun exposure might enhance the athletic performance induced by the dietary nitrate supplementation.
The theory proved to be correct; although sun exposure did not improve cycling times by itself, when combined with the nitrate supplementation, cycling times improved significantly.
It may surprise some people to realize that ultraviolet radiation (UVR) from sun beds or sun lamps has been used since before 1950 to enhance athletic performance.[2] As early as 1938, Russian researchers reported that a course of UVR significantly improved speed in the 100-meter dash among four students when compared with controls that did not have the radiation, although both groups were undergoing identical daily training.[3] The non-irradiated group improved by 1.7% but the irradiated group improved by 7.4%. Another study conducted over ten weeks showed that cardiovascular endurance improved remarkably among athletes in training who were irradiated vs. those who were not.[4] The irradiated athletes improved by 19.2% compared to 1.5% among the non-irradiated group.
There are numerous studies from Germany showing the efficacy of UVR on athletic performance, most of them from the early days before the idea of sun-lamp produced UVR fell into disrepute because of the attack on tanning beds. What a shame. This method of athletic assistance could produce an impressive improvement in sports performance for so many people, athletic or not. Strength improves, stamina improves, quickness improves and speed improves with UVR radiation, which of course is also part of sunlight. The mechanism for this improvement is likely a combination of vitamin D and nitric oxide.
Safely enjoy the sun!
[1] Muggeridge DJ, Sculthorpe N, Grace FM, Willis G, Thornhill L, Weller RB, James PE, Easton C. Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists. Nitric Oxide. 2015 Aug 1;48:3-9.
[2] Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.
[3] Gorkin Z. Gorkin MJ, Teslenko NE. The effect of ultraviolet radiation upon training for the 100-meter sprint.
[4] Allen R, Cureton T. Effects of ultraviolet radiation on physical fitness. Arch Phys Med 1945;10:641-4.