Sculpting Life with Light: The Free Supplement That Improves Health and Performance

Written by Michael Crawley, BSc, BPT, CSCS

Following on from Evelyn’s previous blog post on vitamin D, I want to go deeper into the relationship between sunlight and performance, because light is more than just a source of vitamin D. It interacts with every system in the body, and when used intentionally, it can support energy, recovery, and resilience in powerful ways.

Morning and Evening Light: Nature’s Built-In Protection

Most people intuitively know that sunlight feels different early in the morning and late in the evening. That’s because these times have less UV and more infrared light, which makes them gentler on the skin.

• Morning light prepares your skin for UV exposure later in the day

• Evening light helps repair any UV-related damage by supporting skin recovery
  (Barolet et al. 2016)

This light exposure builds what researchers call a “solar callus”; which is your skin’s tolerance to sunlight. If you skip early and late sun throughout spring and summer, you won’t be adapted to the higher UV exposure of midsummer. Think of it like training volume: if you suddenly try to sprint a marathon without a base, your system isn’t ready.

Light and Nutrition: Feeding the Powerhouse

Nutrition matters for health, performance and recovery, but it’s your mitochondria—the energy factories in your cells—that actually convert nutrients into usable energy.

These mitochondria aren’t just passive processors. They evolved from ancient bacteria that merged with human cells, giving us a massive energy advantage in the evolutionary race (Martin & Mentel, 2010).

Here's the kicker of how it ties in with light:

• Infrared light (especially in the morning and evening) supports mitochondrial function, enhancing energy production and reducing cellular stress (Arranz-Paraíso et al., 2023)

• Always eating meals, indoors under artificial light or while watching a screen, may be hampering energy utilization

• Obviously it is not always possible to eat outside or match the rhythm of the seasons and days. But, if you have the chance to eat breakfast outside or catch the sunrise with your morning coffee, take it. It is certainly a choice I would encourage.  
  

Circadian Rhythm, Injury and Rehab

Circadian rhythm might sound technical, but it's really just your body's internal timing system. Every organ in your body, including your muscles, liver, kidneys, and tendons, has its own internal clock. These clocks help control when key processes like energy production, waste removal, and tissue repair happen.

If everything happens at once, the system falls apart. Imagine working at an airport where every flight tries to take off and land at the same time. That’s what happens in the body when your circadian rhythm is off.

Your body’s master clock (called the suprachiasmatic nucleus) is located just behind your eyes. It keeps all the other cellular clocks running in sync, and it’s set primarily by light, both through your eyes and your skin.

Why It Matters for Injuries

If you're dealing with something like tendinopathy (whether Achilles, patellar, or otherwise), improving your circadian rhythm can help improve your rehab outcomes.

Recent research by Møbjerg et al. (2025) highlights how timing impacts tendon healing and adaptation. Scheduling rehab in the morning or aligning your recovery routine with your body’s natural rhythm can make a meaningful difference.

Cartilage health may also benefit. A 2023 review by Rogers and Meng suggests that long-term outcomes in osteoarthritis and cartilage degeneration could be improved by supporting your circadian health and light environment.

Over time, this is where the airport analogy can occur in the body. The master clock losing control over other body cell clocks.

When Modern Life Gets in the Way

This is where excessive technology at night can create problems. High colour temperature lighting and excessive blue light exposure in the evening can trick the master clock into thinking it is earlier in the day than it actually is.

This exposure mainly comes from phones, laptops, tablets, and modern LED lighting. Over time, this constant signal disruption interferes with the body’s natural timing, making it harder to regulate sleep, recovery, and tissue repair.

Over time, this misalignment disrupts your body's internal timing, which can throw off recovery, sleep, and performance. The result is internal chaos (like our crowded airport) where energy production, healing, and cellular turnover all fall out of sync.

If you're serious about performance or injury rehab, it’s not just about what you do in the gym. It’s also about when and how your body is able to recover. And light plays a bigger role than most people realize.

Easy IMplementation

• Get outside early: Morning sunlight on your skin and eyes before technology or meals can anchor your circadian rhythm.

• Bookend your day with light: Morning and evening light help your body adapt to stronger sun exposure and support repair.

• Rehab with timing: Improving circadian rhythm can help rehabilitate and improve the health of tendons and cartilage.

• Control your night environment: Use soft, warm lighting in the evening. Try candles, red-spectrum bulbs, or blue light filters (e.g., Iris for screens).

You can’t out-supplement a poor light environment. Sunlight is free, powerful, and foundational to human health; and learning to use it wisely can support everything from injury recovery to daily energy.

References

• Barolet D, Christiaens F, Hamblin MR. Infrared and skin: Friend or foe (2016). J Photochem Photobiol B;155:78-85. doi: 10.1016/j.jphotobiol.2015.12.014.

• Martin W, Mentel M. The Origin of Mitochondria. Nature Education 3(9):58 (2010).

• Arranz-Paraíso D, et al. Mitochondria and light: An overview of the pathways triggered in skin and retina with incident infrared radiation. J Photochem Photobiol B: Biology (2023), 238, p. 112614. doi: 10.1016/j.jphotobiol.2022.112614.

• Møbjerg A, et al. Role of the tendon circadian clock in tendinopathy and implications for therapeutics. Int J Exp Pathol. 106(3), 2025.

• Rogers N, Meng QJ. Tick tock, the cartilage clock. Osteoarthritis and Cartilage 31(11), 1425-1436 (2023). doi: 10.1016/j.joca.2023.05.010.
  

Vitamin D in Vancouver: What You Need to Know About Deficiency, Sunlight, and Supplementation

Written by Evelyn Calado, MKin, CSCS, RKin

Living in Vancouver means dealing with long, dark winters and very little direct sunlight. Because vitamin D is made in the skin through UVB exposure, people living at northern latitudes are at a much higher risk of vitamin D deficiency. Even active people who train regularly or spend time outdoors often assume they are getting enough, but research shows that vitamin D levels are commonly low in Canada (and globally too). For athletes, lifters, and anyone trying to support their health, recovery, and immune system, understanding how vitamin D works can make a meaningful difference.

What Vitamin D Actually Does

Vitamin D is often associated with bone health; and yes, it helps the body absorb calcium. But that’s just one of its many jobs.

Vitamin D is technically a fat-soluble hormone, and it interacts with receptors throughout the body. It plays a key role in:

• Immune function

• Inflammation regulation

• Muscle strength and recovery

• Mood and cognitive health

• Bone remodeling and density

Vitamin D receptors are found in immune cells, muscle cells, and even in the brain. So when you’re low, it doesn’t just affect your bones; it can impact recovery, training capacity, and even your ability to fight off colds or feel mentally sharp.

Most People Are Deficient and Don’t Know It

Multiple studies have shown that a large percentage of the population is vitamin D deficient, especially in northern latitudes.

If you live in Vancouver or anywhere else north of the 49th parallel, the odds are stacked against you. From October to April, we don’t get enough UVB rays from the sun for the body to produce vitamin D naturally. Even in summer, many people are indoors most of the day. And here’s something most people don’t realize: Wearing sunscreen blocks UVB rays, which are required for vitamin D synthesis.

To be clear, I am not telling anyone to skip sunscreen entirely or to intentionally burn themselves. Be smart. But understand that even if you go outside, if you’re wearing sunscreen, your body may still not be making enough vitamin D.

Vitamin D Recommendations for Athletes and Active Adults

In Canada, the current Recommended Dietary Allowance for vitamin D is:

• 600 IU per day for individuals aged 9 to 70

• 800 IU per day for adults over 70

These recommendations, established by Health Canada and the Institute of Medicine (Ross et al., 2010), are designed to prevent deficiency and maintain bone health. They aim to keep serum 25(OH)D above 50 nmol per L, which is considered the minimum threshold for sufficiency in the general population.

However, this RDA was created exclusively around bone-related outcomes, not broader health, immune, or performance considerations. Because of this, many vitamin D researchers argue that these intake levels are too low for individuals seeking optimal health or performance, including athletes (Heaney and Holick, 2011; Holick et al., 2011; Cannell et al., 2009).

Higher Intake Recommendations for Those With Limited Sun Exposure

The Endocrine Society provides a more practical guideline for people who do not obtain regular sun exposure, recommending:

• 1,500 to 2,000 IU per day of vitamin D3 (Holick et al., 2011)

This aligns closely with what I was taught in my graduate sport nutrition coursework.
Around 2,000 IU per day from autumn through spring can help maintain sufficient levels.

In some cases, individuals may still require additional supplementation in summer depending on lifestyle, skin pigmentation, indoor training, and geographic location.

Vitamin D Toxicity: Extremely Rare

Vitamin D toxicity is very uncommon and typically results from accidental consumption of extremely high supplemental doses due to manufacturing errors (Cannell et al., 2008; Holick, 2007).

Key safety points:

• Ten thousand IU per day for up to five months has not been shown to cause toxicity in research (Holick, 2007)

• Sunlight cannot cause vitamin D toxicity because the body naturally limits how much vitamin D it produces

My Experience with High-Dose Supplementation

For the past four years, I have personally taken ten thousand IU per day of vitamin D3. I recently paid for a private vitamin D blood test through LifeLabs. Despite consistently taking what is considered a high dose, my bloodwork showed I was only in the middle of the normal reference range.

This is not a prescription or suggestion that others should follow my exact protocol. It is simply to illustrate that if someone supplementing aggressively is barely hitting mid-range values, many others may be even lower than they realize.

When and How to Take Vitamin D

• Take vitamin D with a meal that contains fat to enhance absorption

• Always pair it with vitamin K2, to ensure proper calcium utilization and reduce any risk of calcification in the arteries

• Ideally take it earlier in the day as vitamin D may influence circadian rhythms and melatonin production

Who Should Supplement

If you live in Canada, especially Vancouver or anywhere with long winters, the odds are high that your vitamin D levels are not optimal. Athletes, in particular, benefit from maintaining sufficient levels for:

• Bone health and density

• Immune support during periods of high training stress

• Recovery and muscle repair

• Mood and mental focus

Even if you are not experiencing symptoms, a blood test is the only way to know for sure. Ask your doctor or healthcare provider for a requisition. In BC, you can also request private testing through LifeLabs.

If you want support building a training plan the improves recovery, strength, and overall health, you can learn more about our services.

Key Takeaways

• Vitamin D is essential for health, performance, and recovery

• Most Canadians are low due to latitude, climate, and indoor living

• Sunscreen blocks UVB rays needed to produce vitamin D

• Six hundred to eight hundred IU per day may not be enough, especially for athletes

• Vitamin D3 should be taken with fat and paired with K2

• Blood testing is the only way to confirm your status

• Always consult with a healthcare professional before making changes to your supplement routine

Bottom Line: Everyone Should At Least Consider It

In my opinion, almost everyone in Vancouver should be supplementing with vitamin D, especially through the fall and winter. It supports immunity, recovery, mood, and bone health. Unless you’re getting regular blood work, you probably don’t know if you are low.

For athletes and lifters, it is a low-cost, high-reward investment in your long-term health and performance.

Disclaimer

This post is intended for educational purposes only. I am a strength and conditioning coach, not a medical professional. Please consult your doctor or a registered healthcare provider before beginning any supplement protocol.

References

Cannell, J. J., Hollis, B. W., Sorenson, M. B., Taft, T. N., and Anderson, J. J. (2009).
Athletic performance and vitamin D.
Medicine and Science in Sports and Exercise, 41, 1102 to 1110.

Cannell, J. J., Hollis, B. W., Zasloff, M., and Heaney, R. P. (2008).
Diagnosis and treatment of vitamin D deficiency.
Expert Opinion on Pharmacotherapy, 9, 107 to 118.

Heaney, R. P., and Holick, M. F. (2011).
Why the IOM recommendations for vitamin D are deficient.
Journal of Bone and Mineral Research, 26, 455 to 457.

Holick, M. F. (2007).
Vitamin D deficiency.
New England Journal of Medicine, 357, 266 to 281.

Holick, M. F., Binkley, N. C., Bischoff-Ferrari, H. A., Gordon, C. M., Hanley, D. A., Heaney, R. P., Murad, M. H., and Weaver, C. M. (2011).
Evaluation, treatment, and prevention of vitamin D deficiency.
Journal of Clinical Endocrinology and Metabolism.

Ross, A. C., Taylor, C. L., Yaktine, A. L., and Del Valle, H. B. (2010).
Dietary Reference Intakes for Calcium and Vitamin D.
National Academies Press.

Why Women Should Think Twice About Cold Plunges

Written by Evelyn Calado, MKin, CSCS, RKin

Cold plunges are everywhere right now. Scroll through social media, walk into any boutique gym, or listen to the latest biohacking podcast, and you're bound to hear someone praising the "recovery magic" of ice baths. But there's a problem: this recovery trend is not built for female physiology. And no one seems to be talking about it.

As a woman, especially one training hard and aiming to get stronger, faster, or more resilient, you need to know this: cold plunges can actually hinder your progress.

The Hype vs. The Science

The fitness industry often pushes one-size-fits-all solutions that are, in reality, designed around male physiology. Cold water immersion is no exception. The main argument for it is that it reduces inflammation and muscle soreness. But what’s rarely discussed is that blunting inflammation also blunts adaptation—the very thing you're working hard for in your training.

A key study published in The Journal of Physiology (2015) found that post-exercise cold water immersion significantly reduced long-term gains in muscle mass and strength by suppressing key anabolic signaling pathways. In simpler terms, jumping into a cold plunge after lifting can shut down the processes your body needs to get stronger.

The Female Factor: Why It’s Worse for Women

Dr. Stacy T. Sims, PhD, exercise physiologist and author of ROAR, explains that women already have a more robust anti-inflammatory response, largely due to estrogen. This is great for recovery in general—but it also means that adding more inflammation-suppressing strategies (like cold plunges) can tip the balance too far.

Here’s what that means:

• Estrogen helps buffer inflammation, so you don’t need the added suppression from cold water.

• Cold plunges inhibit mTOR signaling, a critical pathway for muscle protein synthesis. Since women already face challenges building and maintaining lean muscle due to fluctuating hormone levels—particularly during the high-progesterone phase of the menstrual cycle—this further suppresses adaptation.

• Women have a shorter post-exercise anabolic window. That means the timing and environment for recovery matter more. Cold exposure immediately post-training can close this window prematurely.

Heat, Not Cold, Supports Female Recovery

Dr. Sims recommends heat-based recovery tools for women, such as sauna use or hot baths. Heat increases blood flow, supports mitochondrial adaptations, and promotes muscle repair without blunting the natural signals for strength and hypertrophy.

Where cold shuts down your body’s growth processes, heat helps amplify them—especially beneficial for women looking to increase muscle mass, endurance, and overall athletic performance.

Let’s Talk About the Real Issue

This isn’t just a science debate. It’s a visibility problem. Right now, women are being told to do what’s trending without being informed of how it might hurt them. The fitness industry is ignoring female physiology. And it’s not okay.

If you're a woman who trains, lifts, runs, or just wants to be strong and healthy, you deserve better than a one-size-fits-all recovery strategy. You deserve recovery tools that actually work with your body, not against it.

So the next time someone tells you to jump into a cold plunge for recovery, remember that your physiology is different. And according to Dr. Stacy Sims and peer-reviewed research, cold plunges may be doing more harm than good for women.

Let’s change the conversation.

The Science of Sleep: How to Optimize Recovery and Performance

Written by Evelyn Calado, MKin, CSCS, RKin

Sleep is one of the most critical, yet often overlooked, components of overall health and athletic performance. High-quality sleep is essential for physical recovery, cognitive function, and long-term well-being. Whether you're an athlete striving for peak performance or someone simply looking to improve daily function, optimizing sleep should be a top priority.

How many hours should you sleep a night?

Research generally suggests that most adults should aim for 7 to 9 hours of sleep per night to maintain overall health, with individual needs varying based on factors like age, lifestyle, and genetics. For athletes, the recommendations can differ slightly due to the physical demands placed on their bodies.

• General population:

  • Adults: 7–9 hours per night

  • Teens: 8–10 hours per night

  • Children: 9–11 hours per night

• Athletes:
  Athletes often require more sleep for recovery, muscle repair, and optimal performance, with some research suggesting that 8–10 hours per night may be ideal, especially for those who train intensely or frequently

The Importance of Sleep for Health and Performance

Physical Recovery and Performance

Sleep is when the body undergoes the majority of its repair and recovery processes. During deep sleep (slow-wave sleep), the body increases the release of human growth hormone (HGH), which is crucial for muscle repair, bone growth, and tissue regeneration (Leeder et al., 2012). Additionally, inadequate sleep can lead to decreased glycogen storage, reduced muscle protein synthesis, and impaired immune function, all of which can negatively impact athletic performance (Halson, 2014).

For athletes, studies have shown that sleep deprivation leads to reduced reaction time, impaired motor function, decreased endurance, and an increased risk of injury (Fullagar et al., 2015). A study on basketball players found that increasing sleep duration improved sprint times, shooting accuracy, and overall performance (Mah et al., 2011).

Cognitive Function and Decision-Making

Cognitive function is just as critical as physical performance, especially in sports that require strategic thinking, quick reactions, and split-second decision-making. Poor sleep has been linked to impaired memory, decreased attention span, and slower reaction times (Walker, 2017). For athletes, this means a diminished ability to anticipate plays, make precise movements, and adapt to in-game situations.

Hormonal Balance and Mental Health

Sleep plays a vital role in regulating hormones, including cortisol (the stress hormone) and testosterone. Sleep deprivation increases cortisol levels, which can lead to elevated stress, impaired recovery, and increased fat storage (Samuels, 2008). At the same time, sleep is necessary for optimal testosterone production, which is important for muscle growth, strength, and recovery.

Additionally, inadequate sleep is linked to mood disturbances, increased risk of depression and anxiety, and overall reduced well-being. A well-rested athlete is not only physically prepared but also mentally sharper and more resilient.

How to Optimize Sleep for Better Recovery and Performance

1. Maintain a Consistent Sleep Schedule

Going to bed and waking up at the same time every day helps regulate your body’s internal clock (circadian rhythm), leading to better sleep quality. Inconsistent sleep patterns can disrupt recovery and performance (Dijk & Archer, 2009).

2. Create an Ideal Sleep Environment

• Keep it Cool: The optimal room temperature for sleep is between 16-19°C (60-67°F). I personally take this to the next level by opening all bedroom windows before bed to maximize cool airflow

• Eliminate Light: Darkness signals the brain to produce melatonin, a hormone that promotes sleep. Use blackout curtains or an eye mask

• Reduce Noise: White noise machines or earplugs can help block disruptive sounds. I sleep with an air purifier on, which not only improves air quality but also provides soothing background noise

• Incorporate Plants: Snake plants are a great addition to the bedroom as they improve air quality by filtering toxins and increasing oxygen levels, which can promote better sleep

3. Minimize Screen Time and Optimize Lighting

Blue light from phones, tablets, and TVs suppresses melatonin production and interferes with sleep quality. Try to avoid screens at least 60 minutes before bedtime or use blue light filters (Chang et al., 2015).

One of my biggest nighttime game-changers has been switching all bedroom lights to red light bulbs. Red light has been shown to have minimal impact on melatonin production, making it an ideal choice for nighttime lighting. I even installed red puck lights in the bathroom to prevent harsh light exposure when brushing my teeth or washing my face at night.

A dimly lit bedroom bathed in a warm red glow from red light bulbs, creating a calming atmosphere ideal for restful sleep.

4. Prioritize a Pre-Sleep Routine

Establishing a wind-down routine can signal to your body that it’s time for rest. Consider:

• Reading a book for 30-60 minutes before bed (this has been a game-changer for me)

• Practicing deep breathing or meditation

• Gentle stretching or mobility work

5. Manage Caffeine and Alcohol Intake

Caffeine has a half-life of 5-6 hours, meaning it can stay in your system for a long time. Avoid consuming caffeine at least 6 hours before bed. While alcohol might make you feel sleepy, it disrupts REM sleep and overall sleep quality (Roehrs & Roth, 2001).

6. Try Magnesium Spray for Relaxation

Another tip worth trying is applying magnesium spray to the bottoms of your feet before bed. Magnesium plays a key role in muscle relaxation, stress reduction, and sleep regulation. Some people find it helps improve sleep onset and quality, making it a great addition to your nighttime routine.

7. Use Sleep Tracking to Optimize Habits

Wearable technology and sleep tracking apps can provide insights into sleep patterns and help identify areas for improvement. Tracking heart rate variability (HRV) and sleep duration can help athletes understand their recovery needs better (Walsh et al., 2021).

Final Thoughts

Sleep is a fundamental pillar of health and performance. It impacts everything from physical recovery and injury risk to cognitive function and hormonal balance. Prioritizing high-quality sleep through consistent habits, proper sleep hygiene, and lifestyle adjustments will enhance athletic performance, mental clarity, and long-term health.

Investing in better sleep isn’t just about feeling well-rested—it’s about optimizing your body’s ability to perform and recover at its highest potential. Train hard, recover smart, and sleep well.

References

• Chang, A. M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232-1237.

• Dijk, D. J., & Archer, S. N. (2009). Circadian and sleep-dependent aspects of memory performance. Progress in Brain Research, 169, 107-135.

• Fullagar, H. H., et al. (2015). Sleep and recovery in team sport. Int. J. Sports Physiol. Perform., 10(8), 950-957.

• Walsh, N. P., et al. (2021). Sleep and the elite athlete. Int. J. Sports Physiol. Perform., 16(5), 572-573.

• Walker, M. P. (2017). Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner.