Why More Sunlight Will Improve Your Health, Muscular Performance and Strength

Your eyes are the gateway to your brain. The natural light that filters through your eye to be processed by your brain has a direct impact on your health.

And anything that impacts your health, also impacts your workout performance levels.

We don’t necessarily think of light as being important to our overall health, let alone impacting our strength training and weightlifting. But it can as I will explain. I’ll also give you 10 easy ways to get more natural light in your life at the end.

Benefits of natural light to your health

The eye picks up light in non-visual ways, something which wasn’t known until the early 2000s.

Aside from giving us access to see and understand the world, natural light is crucial for our health, mood, bodily systems, plus chemical levels and hormone regulation.

  • Improves sleep (huge area for better training performance!)
  • Produces vitamin D (vital for many aspects of health, including healthy testosterone levels)
  • Crucial in regulating all bodily functions, including hormone levels and metabolism
  • Improves wellbeing and boosts mood
  • Can improve focus and productivity, including in the gym

Sunlight improves sleep – the best natural performance enhancer there is!

Our eyes send complex visual signals to our brain. We all know this.

But a separate nerve pathway also sends non-visual sensory information to a different part of the brain. It’s this pathway that has an impact on your health.

This nerve pathway spans from a group of ganglion cells on the retina where information gets relayed to brain areas that control our circadian rhythm, hormone regulation, metabolism and feelings.

Your circadian rhythm is a 24 hour internal body clock. It’s sometimes known as the sleep/wake cycle and basically governs and coordinates all bodily functions that occur over a 24 hour period, including whether we feel alert or sleepy. This rhythm must be reset on a daily basis in order to remain synchronous with the external environment. Your body achieves this through exposure to light and darkness.

Our bodies evolved to be alert and active during daylight hours and sleepy when the sun set so our bodies can recover, repair and recalibrate. It’s why we need darkness as much as we do light.

Exposure to sunlight sets your sleep pattern

sunset helps set sleep pattern important for workout performance

Light is the most powerful cue that sets sleep pattern. And sleep is the most important state for full recovery, growth and repair.

One of the best things we can do to get a good night’s sleep is expose ourselves to early morning light, especially at sunrise.

Information from early light gets sent to the brain’s master clock and reinforces our natural circadian rhythm. Morning light tells your body (more specifically the pineal gland) to offset the release of melatonin for now, increase the amount of cortisol to get us going and increase our core body temperature. These are all key features for weight training and gym performance.

It also informs our clock to increase melatonin release in around 12 hours’ time to aid sleep onset.

The natural warmth of sunlight is key in warming up our body, facilitating our natural thermoregulation process and also stimulating cortisol production.

A very recent study from 2020 highlighted the importance of the type of light we see at sunrise and sunset, including sky colour changes. The contrast in colour between that lovely orange/yellow hue with the dark blue is subconsciously processed by the brain and may be a key stimulus in circadian timing.

Exposing your eyes to the sunrise sky and sunset sky for a couple of minutes can work wonders for your circadian rhythm and sleep pattern, and therefore muscle gains.

Andrew Huberman Lab Appreciation

For more information on this I couldn’t recommend Dr Andrew Huberman enough. He runs a research lab at Standard University, has his own fantastic Huberman Lab podcast and is active on Instagram sharing extremely useful, free information.

If you can’t get up at sunrise or it’s a bit too early to start your day, get outside as soon as you wake up and soak up a few minutes of natural light. It’s important that light hits your skin, particularly on your face, hands and eyes (apply a bit of common sense here please). Even on cloudy days when you can’t see the sun, plenty of light is still getting through which your body detects, and because of the wavelength, your brain can determine that it’s the morning. Pretty amazing eh?

For even better and more highly tuned circadian rhythms, continue to get doses of sunlight throughout the day. If it’s tipping down with rain outside or for whatever reason you can’t get yourself outside, then sit next to a window. This all helps to feedback into your body’s master clock.

Artificial light negatively affects the body after dark

Artificial light can seriously disturb our circadian rhythm. Exposing ourselves to bright, especially blue light, after dark when melatonin levels have started to increase can send mixed signals to our brain. Humans have only had this problem since electricity was invented, which allowed us to control light for the first time.

Once the sun has set, replicate this in your home by dimming the lights and limiting that really bright, white light associated with daytime.

It’s particularly important to eliminate bright light completely between the hours of midnight at 4am. If you wake up from your sleep, or if you’re still awake (!), try not to switch on a bright light or look at your phone.

This type of light will immediately tell your body it’s time to wake up and you’ll start producing hormones to keep you awake! If you’re just nipping to the toilet, it might make getting back to sleep quite difficult.

Sunlight produces vitamin D

Perhaps the best-known benefit of sunlight is associated with vitamin D.

For general health, Vitamin D is a very important micronutrient involved in many body processes, including calcium metabolism (important for bone and teeth health), neuromuscular and metabolic functioning, cardiovascular health and normal immune system efficiency.

This essential vitamin may also play a role in reducing the impact or chances of certain diseases, such as heart disease, multiple sclerosis and depression.

For us strength trainers and weight lifters, Vitamin D has been linked to reduced inflammation, increases in muscle protein and even has a correlation with testosterone levels.

You can get vitamin D through certain foods (salmon, sardines, egg yolk) and supplements, but unlike other essential vitamins, sunlight, or more specifically UVB radiation, allows our body to produce its own vitamin D directly through a photosynthetic reaction.

When your body has enough vitamin D, it simply switches the synthesis process off. Again, pretty amazing.

bodybuilder weight training strength gains

Sunlight improves your mood and wellbeing

Serotonin. You might have heard of it. It’s a complex hormone that plays a role throughout your whole body, from impacting mood and emotions to motor skills, cognition and wound healing.

In the brain, serotonin is thought to play a significant role in the regulation of moods and memory. This hormone, and indeed the wider serotonergic system, plays a key role in depression, susceptibility to depression and in its treatment with medication.

The link with weight lifting here is that being in a better mood means you’re more likely to be up for training. You’re not going to want to skip a day and wallow in self pity. Even more, resistance training is great for mental health, which helps complete the positive feeling circle.

Research has told us that higher serotonin levels are linked with more positive moods and a calmer outlook, so how do we increase levels of this hormone? One way to naturally increase serotonin levels – yes, you’ve guessed it – is through exposure to sunlight.

Serotonin is also a precursor for the important sleep hormone melatonin, where it gets converted from one to the other in darkness. More sunlight equals more serotonin.

Don’t go thinking indoor lights are a good substitute for natural either. Sunlight gives off between 50,000 and 100,000 lux (light measurement unit), which completely and quite literally outshines a normal light bulb which produces 250-500 lux.

Natural light from the sun is at least a thousand times brighter than any light we’ll get indoors.

What about the sunlight’s harmful effects on our skin?

Defining what constitutes ‘too much’ sun depends on your skin type, where you are in the world and at what time of the day your skin is exposed to direct sunlight.

The World Health Organisation suggest that sunlight exposure to arms, hands and face 2-3 times a week for up to 15 minutes a time is enough to reap the vitamin D boosting benefits. Wearing sunscreen or covering your skin with clothing will block the sun’s rays, meaning you won’t get the benefit. The WHO advise to wear sunscreen and protect your skin if you’re going to be exposed for more than 15 minutes.

The main message from top-level health organisations over the past century has focussed on the negative associations of too much sun exposure.

Excessive sun (i.e. ultraviolet radiation) exposure accounts for around 1.5 million, or 0.1%, of the total global burden of disease in disability-adjusted life years (DALYs). This is a measure of how much a person’s expectancy of a healthy life is reduced by premature death or disability caused by disease.

On the flip side, there’s a much larger annual disease burden of 3.3 billion DALYs associated with low levels of UVR exposure, mainly coming from vitamin D deficiencies.

10 easy ways to get more sunlight

By now I hope you’re striving to get more sunlight in your life to improve your general health and feel the positive impacts in the gym.

With Westeners spending around 90% of the life indoors, it’s incredibly important that we find ways to enjoy and reap the health benefits of sunlight.

Here are 10 top tips to get more sunlight:

  1. If you can get up and watch the sunrise, do it. If that’s not really that feasible see point 2.
  2. As soon as you wake up, stand outside for a few minutes. If the weather’s an issue (as it often is in the UK), get yourself as close as you can to a large window and soak up the rays. You don’t have to be able to see the sun. If you workout in the morning, doing this before a gym session will help kickstart your bodies systems and hormone production.
  3. If you can take a 20-30 minute walk outside before you start work or your daily errands, then do this. Make sure your hands and face are exposed to the light.
  4. Make sure you get outside on your dinner/lunch break. I’m not going to say walk for an hour because this probably isn’t feasible for most, but if you can get in another 20/30 minute walk, even if it’s overcast and drizzling, you’ll be exposing yourself to a different wavelength of light than you did first thing in the morning. You’ll also be upping your non-exercise activity, which is great – it might also help your legs recover if you’v’e hit leg day!
  5. Ideally, take additional 10-15 minute walks in at mid-morning and mid-afternoon. These really help to tune up your brain and circadian rhythm as to what time of day it is and diminish the effects of all that artificial light.
  6. If you don’t eat much vitamin D containing food (oily fish, red meat, egg yolks) and don’t get much sunlight, consider taking a vitamin D supplement.
  7. Sit next to a window when working.
  8. When the sunsets, don’t over-expose yourself to bright lights including a bright phone screen and overhead room lights. Up your lamp game and consider choices such as salt lamps that give off a natural sunset orange colour. If you’ve got a smartphone, change settings to ‘night shift’ or dark mode and set it to sleep mode an hour before bed.
  9. Make sure your bedroom is very dark. Black out blinds are great, especially if your room is near a street lamp.
  10. If you do wake up at night, don’t exposure yourself to bright (white or blue) light. Waking up and looking at your phone won’t do you any favours in getting back to sleep. Exposing yourself to bright light between midnight and 4am can have negative effects on your circadian rhythm.

Wrap Up – Why more sunlight will benefit your weight training

It’s often the things you do away from the gym that can really impact your training performance (both positively and negatively!)

If you don’t fuel your body correctly the day before with the right amount of calories and macronutrients, your performance will suffer. If you don’t get your pre-workout routine sorted, you will notice the difference. If you don’t recovery maximally, you’ll suffer more.

One thing you might not have thought about is sunlight.

The biggest impact of getting correct sun exposure levels during the day is on sleep. And as I’ve said, sleep is the biggest natural performance enhancer there is. There are very, very good reasons why sleep has evolved and why we need between 7-9 hours.

It’s during sleep where your muscles repair, your body recovers and your brain processes feelings. All of these points are essential for a good weight lifting workout.

Sunlight also has a direct impact on vitamin D. Vitamin D is a crucial micronutrient for general health as well as other aspects including activity levels and muscular strength.

So, get more sunlight in your life and revel in the benefits it will bring to your strength training.


Reference list and further reading

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717723/
  2. https://www.nature.com/scitable/knowledge/library/overview-of-hominin-evolution-89010983/   https://www.researchgate.net/publication/340469238_Neuroscience_A_Chromatic_Retinal_Circuit_Encodes_Sunrise_and_Sunset_for_the_Brain
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290997/
  4. https://www.healthline.com/health/food-nutrition/benefits-vitamin-d#fights-disease
  5. https://www.mdpi.com/2072-6643/8/1/56/htm?source=post_page-
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077351/
  7. https://www.healthline.com/health/depression/benefits-sunlight#mental-health
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942271/
  9. https://www.who.int/uv/health/solaruvrad.pdf?ua=1