How Sleep and Stress Affect Running Performance & Injury Risk

The Role of Sleep in Running Performance

• Quality sleep is essential for runners. Sufficient, restorative sleep directly improves aerobic endurance, reaction time, speed, and coordination. Runners who sleep well are less likely to experience fatigue and reach exhaustion too quickly.

• Sleep deprivation impairs performance. Lack of sleep raises perceived effort, reduces endurance, slows recovery, and increases injury risk. Studies show runners experience slower sprint times, reduced glycogen stores, decreased strength, and elevated fatigue when sleep deprived.

• Injury prevention: Optimal sleep supports immune function, aids tissue recovery, and reduces the likelihood of injuries or infections. Chronic sleep loss increases susceptibility to running injuries because tissues do not repair optimally between workouts or races.

• For ultra-distance races, sleep strategies become part of performance: while short-term sleep deprivation may sometimes be tolerated or strategically used in events, for longer distances, sleep loss severely compromises performance and increases health risks.

The Impact of Stress on Runners

• Elevated stress levels disrupt sleep, reduce enjoyment, and negatively affect long-term health. Stress leads to poor sleep, higher injury risk, slower recovery, and less effective performance gains from training.

• Cortisol, the stress hormone, increases with physical and emotional stress. High cortisol impairs recovery, affects mood, hinders muscle repair, and can even suppress the immune system.

• Running under stress: Runners who don't manage stress effectively notice slower times, higher perceived exertion, and often suffer more injuries or setbacks. Stress can manifest as muscle tension, poor focus, and reduced coordination, compounding the effects of sleep deprivation.

Practical Advice for Runners

• Prioritise sleep: Aim for 7–9 hours per night and adopt good sleep hygiene—regular sleep/wake times, cool dark room, and wind-down routines.

• Manage stress: Use relaxation techniques (meditation, deep breathing, gentle exercise), and address sources of emotional or work-related stress.

• Monitor recovery: Be alert to signs of low mood, poor sleep, persistent fatigue, or lingering injuries—they’re signals to rest, recover, or seek support.

Runners who consistently get good sleep and manage stress enjoy stronger performance, lower injury risk, and better overall well-being, while those who neglect these factors will struggle with fatigue, slower race times, and more frequent injuries.