Why Sleep Matters
Sleep is as essential as nutrition. It’s one of the body’s basic needs and plays a fundamental role in overall health. While we sleep, the body:
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Repairs cells
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Regulates hormones
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Strengthens the immune system
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Optimizes energy for the next day
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Protects the heart and emotional balance
What happens when sleep is lacking? According to the WHO, sleep deprivation is associated with a higher risk of cardiovascular disease, diabetes, obesity, mental health disorders, and cognitive performance issues.
Yet today, good sleep is increasingly rare. A fast-paced lifestyle, stress, and anxiety make it harder than ever to achieve deep, restorative rest.
This is where cold-plunging comes in.
What Is Cold-Plunging?
Cold-plunging is one of the ways we can deliberately expose the body to cold. How? Through a full-body plunge in very cold water. Sessions usually last between 2 and 5 minutes, with temperatures below 13°C.
Cold exposure offers a wide range of benefits:
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Anti-inflammatory effect
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Stronger cardiovascular system
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Dopamine release
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Boost in energy
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Improved circulation
And among all these benefits, one stands out: it improves sleep quality.
How the Circadian Rhythm Works?
The circadian rhythm is your biological clock, it regulates when you sleep and when you feel alert. It’s controlled by external cues such as light and temperature. Based on these signals, the brain releases hormones:
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Melatonin: signals that it’s time to rest
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Cortisol: signals that it’s time to wake up and be active
When the circadian rhythm is disrupted, sleep is disrupted too. Fortunately, there are several natural ways to help reset it:
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Gradually adjusting your sleep schedule
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Getting morning sunlight
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Taking a warm shower or sauna before bed
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Avoiding screens at night
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Limiting alcohol, caffeine, and energy drinks
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Doing a cryotherapy session early in the morning
Let’s take a closer look at the last one.
How Cold Impacts Sleep
Resets the circadian rythm
When your internal clock is out of sync, cold-water exposure can help realign it. Two or three minutes in cold water early in the morning give your body a surge of hormones that increase alertness and energy. This can help signal to the body that it’s time to start the day.
A 2015 study (Schaal et al.) evaluated a group of elite synchronized swimmers. After training, they completed 3-minute cryotherapy sessions *using cryogenically cooled air chambers (same effects as cold-plunging).
The results? Cryotherapy helped them tolerate intensive training by preserving their total sleep time leading up to the Olympic Games.
Reduces anxiety and stress (common causes of insomnia)
For many people, difficulty falling or staying asleep is linked to anxiety, depression, and high stress levels.
Cold immersion helps because it triggers:
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The release of feel-good hormones like endorphins
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A reduction in cortisol (the stress hormone)
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A spike in dopamine
Melatonin (the sleep hormone) also depends on dopamine for proper regulation. Together with norepinephrine, dopamine helps control changes in brain activity and the sleep-wake cycle.
All of this contributes to better sleep quality and duration.
Timing Matters
Because cold therapy wakes the body up—thanks to the rush of adrenaline and energy—it’s best to avoid ice baths right before bed. We recommend doing them early in the morning or, if you prefer the afternoon, at least 4 hours before bedtime.
If you do your session later in the day, follow it with a sauna session or warm-water immersion. Both help relax the body and mind, making it easier to fall asleep and stay asleep.
*Disclaimer: The information in this article is for educational purposes only. It is not medical advice and should not replace guidance from a qualified healthcare provider. Always consult your physician before starting this practice, especially if you have any pre-existing conditions.
If you want to learn more about cold-plunging and its effects on mental health, longevity, fat loss, energy, and performance, explore our Wellness Journal.
