Running: why insufficient sleep could increase the risk of injury
In 425 recreational runners, the profile combining short sleep, poor quality and night-time disturbances had the most injuries. An association, not proof of cause and effect.
Doctor Florian A. Vallecillo Cabrera
Author
A 2025 study (Applied Sciences) profiled the sleep of 425 recreational runners and identified four profiles. The "poor sleepers" (short sleep + poor quality + disturbances, ~37%) had an injury probability close to 68%, well above regular sleepers. Observational, cross-sectional study: it shows an association, not causation. Sleep affects muscle recovery, alertness, perception of effort and pain. It remains one factor among others (load, energy, strength, technique). Key message: when sleep deteriorates durably, the body tolerates load less well.
Summary
Runners usually pay a lot of attention to their mileage, their shoes, their diet or their recovery sessions. Yet sleep is an essential component of adaptation to training.
A study published in 2025 identified four sleep profiles in recreational runners. Participants combining insufficient sleep duration, poor sleep quality and more night-time disturbances had a clearly higher injury frequency than runners who slept more regularly.
These results do not mean that a bad night will necessarily cause an injury on the next run. Rather, they suggest that insufficient or disturbed sleep, when it becomes chronic, can reduce the body's ability to withstand the training load.
Why is sleep essential for sports recovery?
Sleep is not a mere period of inactivity. It actively participates in the recovery of many systems used by running. It contributes in particular to:
- tissue repair;
- regulation of the nervous system;
- muscle recovery;
- the consolidation of motor learning;
- hormonal balance;
- the perception of effort and pain;
- alertness and coordination.
Insufficient sleep can thus affect both biological recovery and the quality of the athletic movement.
What exactly does the study show?
The researchers gave 425 recreational runners questionnaires covering, among other things:
- their usual sleep duration;
- its subjective quality;
- night-time awakenings or difficulties;
- their training;
- their recovery;
- their sports injuries.
A statistical method called latent profile analysis then made it possible to group the participants according to their sleep characteristics.
Four runner profiles identified
1. Regular sleepers
They represented about 48% of the participants. They had a relatively satisfactory sleep duration, good subjective quality and few night-time disturbances. This group served as the comparison profile.
2. Poor sleepers
They represented about 37% of the sample. They combined a shorter sleep duration, insufficient quality and more night-time problems. It was in this group that the reported probability of injury was highest.
3. Efficient sleepers
About 8% of runners had relatively short sleep, but of good quality and little fragmented. This profile is a reminder that duration alone is not enough to assess sleep health.
4. Fragmented sleepers
About 7% of participants slept long enough, but with more awakenings or disturbances. Here again, staying in bed for a long time does not necessarily guarantee genuinely restorative sleep.
Do poor sleepers really get injured twice as often?
The study indicates that the group combining the characteristics of poor sleep had an injury probability close to 68%, appreciably higher than that of regular sleepers.
The headline that these runners would get injured "twice as much" summarises this difference in a catchy way, but it must be interpreted with caution. The researchers observed a statistical association. They did not experimentally follow runners by forcing them to sleep more or less. It is therefore impossible to state with certainty that poor sleep directly caused the injuries.
Why might poor sleep favour injuries?
Several biological and behavioural mechanisms are plausible.
Less complete muscle recovery
Training causes normal micro-injuries and neuromuscular fatigue. When sleep is insufficient, the time available to restore tissues and neuromuscular functions may be reduced.
Reduced alertness
Fatigue impairs attention, reaction time, coordination and the ability to adapt to the terrain. In a tired runner, an obstacle, a change of surface or a bad landing may be less well anticipated.
Altered perception of effort
After a bad night, a usual pace may feel harder. The runner may also find it more difficult to correctly assess their fatigue and to adjust their training.
Increased sensitivity to pain
Sleep restriction can increase pain sensitivity. Previously mild symptoms may then be felt more intensely or, conversely, be misinterpreted in a context of fatigue.
Is sleep the only injury factor?
No. A running injury is almost always multifactorial. Sleep interacts with:
- the training load;
- the runner's experience;
- a history of injury;
- muscle strength;
- recovery;
- energy intake;
- the terrain;
- technique;
- certain individual characteristics.
A prospective study of more than 5,200 runners showed in particular that the risk of overuse injury increased when a single session exceeded by more than 10% the longest run performed during the previous 30 days. The largest increases in distance in a single session were associated with the greatest increases in risk. Sleep should therefore be considered a component of risk, and not a single explanation.
Are eight hours of sleep essential?
There is no universal threshold below which a runner would automatically get injured. For most adults, a duration of between seven and nine hours is a general reference. But needs vary according to age, training load, sporting level, health status, stress and accumulated sleep debt.
The regularity and quality of sleep are also important. A person sleeping seven hours continuously and restoratively may recover better than another who stays nine hours in bed with numerous awakenings.
Can it be compensated for with a nap?
A nap can be useful when a night has been too short or when an intense training period increases recovery needs. Studies in athletes suggest that naps can improve alertness and some performance parameters, but the results regarding endurance remain variable. They do not durably replace insufficient night-time sleep.
Two formats can be considered: a short nap of about 20 minutes, which generally limits inertia on waking; a longer nap, close to a sleep cycle, when the context allows. However, a late nap may delay falling asleep in the evening in some people.
When should a session be eased or postponed?
An imperfect night does not systematically require cancelling training. On the other hand, an adjustment may be wise when several signs accumulate:
- significant drowsiness;
- lack of concentration;
- unusual muscle fatigue;
- a feeling of heavy legs;
- irritability;
- unusually high heart rate;
- persistent pain;
- a succession of several insufficient nights.
In this situation, an easy, shorter run, or one replaced by a recovery day, may be preferable to an intense session.
The most common mistakes
Keeping an intense session at all costs
Following a programme does not mean ignoring one's recovery state. The ability to adapt a session is part of intelligent training.
Increasing distance abruptly
A sharp progression in a single run can expose the tissues to a load they are not yet prepared to absorb.
Running in an energy deficit
An energy intake too low relative to sports expenditure can impair recovery, hormonal functions and bone health. Low energy availability is recognised as a factor in decreased performance and increased injury risk.
Confusing normal fatigue with pathological pain
Transient stiffness after a session does not have the same meaning as localised pain that increases with each training.
How to improve your sleep when you run regularly?
The most useful measures remain simple:
- keep relatively regular bedtimes and wake-up times;
- reduce intense light and screens before sleep;
- limit caffeine in the second part of the day;
- avoid very intense training just before bed when it disrupts falling asleep;
- limit alcohol, which fragments sleep;
- keep a dark, quiet and cool bedroom;
- allow enough time in bed;
- adapt the sports load after several bad nights.
The aim is not to reach a perfect number every evening, but to avoid the build-up of a chronic sleep debt.
When should a sleep disorder be investigated?
Persistent poor sleep should not always be attributed to stress or training. A medical assessment may be relevant in the presence of:
- significant snoring;
- reported breathing pauses;
- daytime sleepiness;
- frequent awakenings;
- lasting insomnia;
- restless legs;
- morning headaches;
- persistent fatigue despite sufficient sleep time.
Sleep apnoea or another untreated disorder can compromise recovery, cardiovascular health and the ability to train.
What this study does not demonstrate
This study does not prove that:
- sleeping less than eight hours necessarily causes an injury;
- a single bad night doubles the risk the next day;
- all runners need the same sleep duration;
- improving sleep is enough to prevent all injuries;
- the injuries observed were all caused by fatigue.
It is based on questionnaires and on information reported by the participants. Its design does not allow a certain cause-and-effect relationship to be established. It is also possible that the relationship works both ways: pain or an injury can itself degrade sleep.
The Valorian analysis
This study is a reminder that recovery does not begin after training with a supplement, a massage or a technological device. It begins with sufficiently long, regular and restorative sleep.
Its main value is having assessed several dimensions of sleep simultaneously. Duration alone does not tell the whole story. Prolonged but fragmented sleep may remain unrefreshing, whereas a slightly shorter duration may be better tolerated when it is regular and of good quality.
At Valorian, we consider that injury prevention in runners must combine four pillars: an appropriate progression of the load; a diet that covers energy needs; regular strength training; genuine recovery, of which sleep is the central element.
The right message is therefore not: "Sleep eight hours or you will get injured." It is rather: when sleep deteriorates durably, the body may become less able to tolerate a sports load previously well tolerated. Monitoring sleep can thus be a useful indicator to adjust training, especially when it is combined with unusual fatigue, a drop in performance or the appearance of repeated pain.
Key points
- ◆Of 425 runners, four sleep profiles; the "poor sleepers" (~37%) with short duration, poor quality and disturbances had a ~68% injury probability.
- ◆It is a statistical association, not proof of causation: an observational, cross-sectional study based on self-reports.
- ◆Duration alone is not enough: long but fragmented sleep may remain unrefreshing; 7–9 h is a reference, but regularity and quality matter just as much.
- ◆Plausible mechanisms: incomplete muscle recovery, reduced alertness and coordination, harder perceived effort, increased pain sensitivity.
- ◆Prevention = Valorian's 4 pillars: appropriate load progression, sufficient energy intake, strength training, and genuine recovery with sleep at its centre.
Valorian level of evidence
- Scientific quality(3/5)
The study is published in a scientific journal and is based on a structured analysis of 425 runners. However, it remains observational, cross-sectional and based on self-reports. It identifies an association, without demonstrating causation.
- Current clinical application(4/5)
Assessing sleep, fatigue and recovery is relevant in injury prevention. However, there is no individual threshold to precisely predict that a runner will get injured.
- Preventive potential(4/5)
Integrating sleep into training decisions could help athletes better adjust their load and recognise periods of vulnerability. Prospective studies using objective sleep measures will be needed to determine whether improving it actually reduces the number of injuries.
References
- De Jonge J, Taris TW. Sleep Matters: Profiling Sleep Patterns to Predict Sports Injuries in Recreational Runners. Applied Sciences. 2025;15(19):10814. Étude sur 425 coureurs amateurs néerlandais analysant durée, qualité et perturbations du sommeil.
- Étude prospective sur plus de 5 200 coureurs : le risque de blessure de surutilisation augmente lorsqu'une seule séance dépasse de plus de 10 % la plus longue sortie des 30 jours précédents.
Frequently asked questions
Does insufficient sleep necessarily cause an injury?
No. The study shows an association, not a direct cause. A single bad night does not necessarily cause injury; it is rather insufficient or disturbed sleep that has become chronic that can reduce the ability to tolerate the training load.
Do you have to sleep 8 hours to avoid injuries?
There is no universal threshold. For most adults, 7 to 9 hours is a reference, but needs vary (age, load, stress, sleep debt). Regularity and quality are as important as duration.
Can a nap compensate for a bad night?
A nap (≈ 20 min, or close to a sleep cycle) can help alertness and recovery after a short night, but does not durably replace insufficient night-time sleep. A late nap may delay falling asleep in the evening.
When should a session be eased or postponed?
When several signs accumulate: drowsiness, lack of concentration, heavy legs, unusual muscle fatigue, high heart rate, persistent pain or several insufficient nights. An easy run or a recovery day is then preferable.
When should you see a doctor for a sleep disorder?
In case of significant snoring, breathing pauses, daytime sleepiness, frequent awakenings, lasting insomnia, restless legs, morning headaches or persistent fatigue despite enough sleep. Untreated sleep apnoea compromises recovery.
