Sleep & Marathon: The most important answers for runners

Good sleep is more than just recovery for marathon runners – it is one of the strongest performance factors overall. While training, nutrition, and equipment receive a lot of attention, sleep is often the decisive fourth pillar that significantly influences pace, resilience, and recovery. However, marathon and ultra runners systematically sleep too little, especially in the days leading up to competitions (Nikolaidis et al., 2023). We have collected the most common questions from runners and answered them based on current scientific findings.

1. How many hours of sleep do runners need during marathon training?

The classic recommendation for adults is: 7 to 9 hours of sleep per night. However, for runners in endurance training, the rule is:
The more intense the training, the greater the need for sleep.

Studies show that the need for recovery can increase by 30–90 minutes per day as training volumes grow – especially during long runs or intensive interval blocks. This is because crucial recovery processes occur during sleep (e.g., Cunha et al., 2023):

• Repair of micro-injuries to the muscles
• Replenishing glycogen stores
• Reducing inflammation markers
• Stable hormone regulation (testosterone, growth hormones, cortisol)

Many marathon runners report that they are significantly more efficient and get through training weeks better with 8 to 9.5 hours of sleep. International studies with professional athletes also show that such extended sleep windows are central for optimal performance (e.g., Cook et al., 2023; Sargent et al., 2021). 

Practical tip: Those who have a lot to do professionally or with family can partially compensate for missing sleep time with a nap.

2. How much does poor sleep affect running performance?

In short: very significantly.

Even a single night with less than 6 hours of sleep can have the following effects:

• Higher pulse at the same pace
• Lower maximum oxygen uptake (VO₂max)
• Less lactate tolerance
• Worsened coordination and running economy
• Increased risk of injury due to poorer stimulus processing

Lack of sleep acts biologically like a stressor: Cortisol rises, muscle recovery is slower, and energy systems remain unbalanced (e.g., Cohen et al., 2009; Milewski et al., 2014).

In a well-known study with endurance athletes, athletes lost up to 10% of their performance & endurance capacity after several nights with sleep deficits – even with identical training conditions (e.g., Craven et al., 2022).

Important: Poor sleep often only affects subjectively delayed. You feel fit but run objectively worse. This is where a sleep tracking tool can help recognize patterns and take countermeasures in time.

3. When should you train at the latest in the evening?

Many runners train late due to work – but timing is crucial to not impair sleep.

Basic rule:

There should generally be at least 3 hours between intensive training and bedtime.

Why?

• Body temperature increases by up to 1 °C through training. The body can only fall asleep when it drops again.
• Stress hormones (adrenaline, cortisol) remain elevated longer after hard intervals.
• Heart rate and metabolism need time to return to rest mode.
   

What does this mean specifically?

• Interval training & tempo runs: at least 3 hours before sleep
• Easier runs: also possible later, at least 1.5–2 hours gap
• Stabilization and strength training: also 2–3 hours gap depending on intensity

A good indicator: When the pulse drops back down after training and comes close to the resting pulse, the sleep window usually slowly opens.

4. Can a nap improve recovery in marathon training?

Yes – and significantly.

A power nap of 10 to 20 minutes can:

• improve reaction time
• reduce training-related fatigue
• accelerate lactate processing
• increase mental freshness
• help better process the training stimulus from the previous day

Longer naps of 45–90 minutes can further promote recovery but carry the risk of sleep inertia immediately after waking. It is important to plan enough time between waking up and training (20-30min) or the desired peak performance (30-90min) for the competition (e.g., Lastella et al., 2021).

Optimal timing: between 1:00 PM and 4:00 PM – precisely when the internal body temperature naturally drops (e.g., Walsh et al., 2021). Late daytime sleep is problematic as it can then delay falling asleep in the evening.

Ideal for training weeks:
Those who have had an especially hard run or are planning interval training later can measurably increase performance with a power nap or extended nap.

5. What to do if you sleep poorly before the competition?

Almost all runners know the restless night before the marathon. Nervousness, thoughts, and anticipation are completely normal. The good news:
The night before the competition is less important than many believe.

The crucial nights are the ones before.
If you sleep well 48 and 24 hours before the start, you have full glycogen stores, stable hormones, and good recovery – even if the last night is short.

To help with nervousness:

• a fixed evening routine
• light meal 3 hours before sleep
• no alcohol, little caffeine
• relaxation exercises or breathing techniques
• no obsessive clock-and-sleep tracking on this night

Practical tip:
15 minutes of quiet lying down before the competition start can have similar effects as a good night's sleep. However, make sure to allow enough activation time to fully gear up again.

How sleep² can support runners

Many runners underestimate how much sleep quality affects training and competition.
The sleep² app was developed in collaboration with Univ.-Prof. Schabus, a leading sleep researcher, and helps to measure sleep in unprecedented quality (Topalidis et al., 2023; Topalidis et al., 2025) – similar to a sleep lab, but at home. Runners quickly see how factors like training, nutrition, or stress change sleep and can better plan recovery phases.
Especially during intensive training phases, this can be a valuable tool to recognize overload and fully exploit performance potential.

Conclusion

Sleep is one of the biggest performance levers in marathon training – often greater than equipment, additional training, or supplements. Those who sleep well recover better, remain injury-free, and maintain training volumes more consistently.
Whether it's a power nap, evening training planning, or routines before the competition: Small changes make a big difference.
And those who understand their own sleep patterns can specifically optimize recovery – the foundation for a successful competition.