If you’ve been feeling more sluggish lately— notably more tired despite “enough” sleep, struggling to get out of bed, and over running in the dark—you’re not alone.
Winter slumps aren’t just mental or motivational. Research shows that reduced daylight around the winter solstice disrupts your biology in ways that directly affect energy, recovery, immunity, and athletic performance.
In this quick tip, we’ll cover:
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Why fewer daylight hours make you feel off
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How this impacts your training and performance
- Simple, science-backed ways to feel more like yourself again
Your Internal Clock Is Getting Confused
The root issue is circadian rhythm disruption—your brain’s internal clock that relies on daylight to regulate energy, hormones, and sleep.
Morning light is the signal that flips your body “on”: increasing alertness, triggering proper cortisol release, and setting you up to wind down later. In winter, many of us wake, commute, work, and return home in darkness, never giving the brain enough light input.
Without that signal, your body stays stuck in a groggy twilight state—tired during the day, wired at night—exactly the opposite of what supports quality training and recovery.
How This Impacts Performance
Reduced daylight also affects neurotransmitters associated with endurance. Research shows that low winter light increases serotonin activity, which directly impairs endurance performance—even in highly trained athletes.
Elevated levels of serotonin are linked to a reduction in time to fatigue (you experience fatigue quicker).
What You Can Do About It
1. Prioritize Strategic Light Exposure
Morning light is the most powerful tool for resetting your circadian rhythm.
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Aim for 5–10 minutes of outdoor light on clear mornings, 10–20 minutes if overcast
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If you miss morning light, afternoon sunlight acts as a helpful second “anchor”
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Even cloudy skies provide enough wavelength exposure to help your brain recalibrate
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Try a cozy walk with the dog or family to start your day, or grab some cocoa and take a stroll before sunset!
2. Focus on Sleep Quality (Not Just More Hours)
Simply “sleeping more” isn’t realistic for many runners. The good news: improving sleep quality can deliver similar benefits.
We know that increasing deep, restorative sleep—without necessarily increasing total sleep time—improves performance, lowers cortisol, and sharpens reaction time.
You can experiment with target sleep support like magnesium, ashwagandha, and tryptophan to help deepen sleep and reduce nighttime cortisol.
In conclusion, try this winter time protocol:
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Get outdoor light within the first hour of waking whenever possible
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Train earlier in the day when you can to stack light + exercise benefits
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Improve sleep quality with evidence-based sleep support supplements
Longer days and brighter mornings are ahead—and with the right strategies, you don’t have to wait to start feeling better.
References
1. https://link.springer.com/article/10.2165/00007256-200636100-00006
2. https://www.cell.com/heliyon/fulltext/S2405-8440(23)06844-5
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC10354314/#:~:text=Key%20Points,to%20feel%20rested%20%5B8%5D.
