Sport & Sleep: A Love-Hate Relationship

Person sleeping in bed wearing running shoes – symbolic image of the link between exercise and sleep.

Sport and sleep are closely linked—sometimes as perfect partners, sometimes as rivals. While regular exercise is often praised as a natural sleep aid, training at the wrong time or intensity can have the opposite effect.

But why does this happen? What is the best time to work out? What intensity should you choose? And for whom does exercise improve sleep, and for whom does it make it worse?

Let’s explore the scientific insights on how exercise affects sleep and how to find the right balance.

Why Exercise Should Improve Sleep

Exercise offers many benefits for sleep quality. Studies show that regular physical activity can:

Reduce the time it takes to fall asleep: It helps burn excess energy and promotes relaxation.
Increase deep sleep phases: Essential for physical and mental recovery.
Reduce sleep disturbances: Aerobic exercise can alleviate symptoms of insomnia.
Stabilize the circadian rhythm: Exercising in the morning or afternoon helps regulate sleep-wake cycles.

Scientific Evidence: A meta-analysis from ETH Zurich (2020) found that exercise, particularly aerobic workouts, improves sleep quality at least 2–3 hours before bedtime. (Source: ETH Zürich, 2020)

When Exercise Can Disrupt Sleep

Despite its benefits, exercise can interfere with sleep if it is too intense or too late in the day. Here’s why:

Increased Adrenaline and Noradrenaline Levels: High-intensity exercise activates the sympathetic nervous system, keeping the body in fight-or-flight mode.
Elevated Body Temperature: Exercise raises core body temperature, but to fall asleep, the body needs to cool down.
Disrupted Circadian Rhythm: Late-night exercise increases cortisol (stress hormone) and suppresses melatonin (the sleep hormone), making it harder to fall asleep.

Scientific Study: A study from Concordia University (2021) found that people who exercised less than 90 minutes before bedtime took longer to fall asleep and had lower sleep quality. (Source: Concordia University, 2021)

When Is the Best Time to Exercise for Better Sleep?

What’s the ideal workout time for better sleep?

Morning or Late Morning (Best 🟢): Boosts serotonin production and strengthens circadian rhythm.
Afternoon or Early Evening (Good 🟡): Good for performance as the body is fully awake.
Late Evening or Night (Problematic 🔴): Can delay sleep onset if too close to bedtime.

Scientific Recommendation: The National Sleep Foundation (2022) advises finishing workouts at least 2–3 hours before bed to avoid sleep disruptions. (Source: National Sleep Foundation, 2022)

What Type of Exercise Is Best for Whom?

Who Benefits from Exercise for Better Sleep?

People with insomnia – Light jogging, walking, or yoga can help.
Older adults – Exercise helps stabilize sleep-wake cycles.
People under stress – Exercise reduces cortisol levels and promotes relaxation.

Who Should Be Cautious?

Highly stressed individuals – Intense exercise can increase cortisol and worsen sleep problems.
Shift workers – Late-night workouts can further disrupt sleep cycles.
Athletes training late at night – Need a cool-down routine to lower adrenaline and body temperature.

Practical Tips to Balance Exercise & Sleep

Choose the right time: Morning or afternoon workouts are best.
Adjust intensity: If exercising at night, opt for light activities like yoga or stretching.
Include a cool-down phase: Stretching or a warm shower can help the body relax after intense workouts.
Limit screen time after late workouts: Blue light inhibits melatonin production.
Stick to a routine: A consistent schedule helps the body adapt to exercise and sleep patterns.

Conclusion: Balance Is Key!

Exercise can both improve and disrupt sleep, depending on when and how it’s done.

Working out in the morning or afternoon supports sleep quality and recovery. Intense training late at night, on the other hand, can negatively affect sleep.

Those who stick to the right timing, intensity, and recovery routines can make the most of the positive effects of exercise for better sleep.

Tip: If you struggle with sleep, experiment with different workout times and intensities to find what works best for you!

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