Sunlight is a mood lifter. No wonder we enjoy seeing more of it after a long, dark winter! There’s a reason people feel cheerier, motivated, and more optimistic in the spring and summer, and the abundance of sunlight is one explanation.
But there’s more. A dose of sunlight may be beneficial for your physique and body composition too. Let’s let at some ways that sunlight may help your physique and fitness level and improve the ways your muscles function.
Sunlight Boosts Vitamin D Production
Your body makes vitamin D when you expose your skin to sunlight. This is a several-step process that involves the skin, liver, and kidneys, but the final result is 1,25-dihydroxycholecalciferol, the biologically active form of vitamin D. You need vitamin D for bone health, but also for a healthy immune system.
Your muscles, too, benefit from having a healthy vitamin D level. Some studies show that having a low vitamin D level reduces muscle strength and function and lowers exercise capacity, the ability to sustain exercise at a sub-maximal intensity. One study published in the American Journal of Sports Medicine found that football players who had a low vitamin D level were more likely to develop bone fractures.
Another interesting study found that professional football players who had higher vitamin D levels had higher odds of getting a contract position in the National Football League. So, if you’re in sports a low vitamin D level could even affect your livelihood! Make sure you’re getting enough of it.
In addition, some studies show that taking vitamin D supplements increases muscle strength, mainly for people who have a low vitamin D level, as many folks in modern society do. Therefore, if you’re low in vitamin D, you might not perform as well at the gym and may not reach your body’s true potential.
These are only associations, but show the importance of having a healthy vitamin D level if you’re physically active. You don’t want to be deficient in the sunshine vitamin and getting more sunlight is one way to avoid deficiency.
Sunlight Affects Melatonin
When you time your sun exposure properly, your body maximizes the amount of melatonin it produces. Why is this important? Melatonin is a powerful antioxidant, released by the pineal gland in your brain. Antioxidants help protect tissues, including muscles, against oxidative stress that can damage them and contribute to premature muscle aging.
Also, if you have an optimal melatonin level, you’ll release a healthy amount of growth hormone, a hormone that aids in muscle gains and fat loss. Therefore, releasing more melatonin may help optimize muscle function and hypertrophy in response to strength training. Plus, melatonin helps with sleep, a lifestyle factor that’s important for muscle gains. Lack of adequate sleep can raise cortisol, a stress hormone that increases muscle breakdown.
How can you maximize melatonin? Expose your eyes to natural light as early in the day as possible, preferably before noon. Ideally, catch the first-morning sunlight by opening the blinds as soon as you wake up. Step outside in the morning light and absorb some light. In the evening, reduce your exposure to light, especially blue light several hours before bedtime. So, light exposure early in the day and complete darkness at night when you go to sleep to optimize your melatonin level.
Sunlight Has Mood-Elevating Benefits
It feels good when you step outdoors on a sunny day. Ever notice that? Why is sunlight so soothing to the body and mind? Sunlight increases serotonin, a brain chemical that helps fight depression and lack of motivation. Some people even suffer from seasonal affective disorder, a seasonal type of depression brought on by lack of sun exposure. If you have this condition, some healthcare providers recommend using a light therapy box to mimic the effects of natural sunlight. Studies show these boxes benefit some people who feel down and out in the winter.
Why do the mood-elevating benefits of sunshine and natural light matter? If you have plenty of serotonin in your brain, your motivation level will be higher, and you can maximize your training. Plus, you’ll sleep better with an optimal serotonin level and that will help you make greater gains when you work out. In addition, better sleep enhances growth hormone release for fat burning and muscle gains.
The Bottom Line
Step outdoors and soak up some sunlight when you have a chance. The earlier you expose your eyes to sunlight in the day, the more you’ll optimize melatonin release and maximize sleep and growth hormone release. Don’t overdo it, though. Too much sun exposure increases the risk of skin cancer, including malignant melanoma.
References:
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- Stacchiotti A, Favero G, Rodella LF. Impact of Melatonin on Skeletal Muscle and Exercise. Cells. 2020; 9 (2):288. Published 2020 Jan 24. doi:10.3390/cells9020288.
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- DeLuca HF: Overview of general physiologic features and functions of vitamin D. Am J Clin Nutr 2004; 80 (6 suppl):1689S-1696S.
- Tripkovic L, Lambert H, Hart K, et al: Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: A systematic review and meta-analysis. Am J Clin Nutr 2012; 95 (6):1357–1364.
- Am J Sports Med. 2015 May; 43 (5):1241-5. doi: 10.1177/0363546514567297. Epub 2015, Feb 3.
- Westmead Institute for Medical Research. “Muscling in on the role of vitamin D: Research shows vitamin D signaling is needed for normal muscle size and strength.” ScienceDaily. ScienceDaily, 26 June 2019.
- Zaki K. Hassan-Smith, Carl Jenkinson, David J. Smith, Ivan Hernandez, Stuart A. Morgan, Nicola J. Crabtree, Neil J. Gittoes, Brian G. Keevil, Paul M. Stewart, Martin Hewison. 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 exert distinct effects on human skeletal muscle function and gene expression. PLOS ONE, 2017 DOI: 10.1371/journal. pone.0170665.
- com. “Sleep and Sunlight: Why Athletes Need to Prioritize Both”
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