Napping and Athletic Performance: What Meta-Analyses Show

Why Do Athletes Nap?

Biphasic sleep — nocturnal and post-lunch — is biologically normal: the post-lunch dip in alertness is observed in most people regardless of food intake and reflects circadian fluctuations in body temperature. In professional sport, two-a-day training sessions create 1–3 hours between sessions, and napping has become a recovery strategy alongside nutrition and massage.

Systematic research into this phenomenon began relatively recently. By 2023, enough data had accumulated for meta-analyses.

What Did the Meta-Analysis of Physical Performance Show?

Boukhris et al. (Sports Medicine, 2023, DOI: 10.1007/s40279-023-01920-2) analyzed 18 studies involving 269 athletes. The sample included athletes with normal nighttime sleep; nap duration ranged from 20–90 minutes. The authors assessed objective measures of physical performance.

Key results:

• Best distance in the 5-meter shuttle test improved significantly: ES = 1.026, p < 0.001 (+8.2 m).
• Total distance in the shuttle test: ES = 0.737, p < 0.001 (+38.5 m).
• Fatigue index decreased: ES = 0.839, p = 0.008 (2.5% improvement).
• Muscle strength did not change significantly: ES = 0.175, p = 0.267.
• 15 of 18 studies were rated as methodologically strong.

How Does Napping Affect Perceived Exertion and Mood?

In 2025, the same group expanded the analysis to 35 studies with 489 participants (Biology of Sport, DOI: 10.5114/biolsport.2026.153310). The focus was on psychophysiological outcomes. The authors included both normally sleeping athletes and those with partial sleep deprivation.

• Perceived exertion (RPE) during exercise: SMD = 1.62, p = 0.008 — significant reduction.
• Subjective recovery: SMD = 1.66, p = 0.009 — significant improvement.
• Fatigue: SMD = 0.91, p = 0.01 — significant reduction.
• Total mood disturbance (TMD): SMD = 0.61, p = 0.008 — significant improvement.
• Certainty of evidence: moderate for RPE, low and very low for other outcomes.

What Did the RCT in Professional Athletes Show?

Teece et al. (SLEEP, 2023, DOI: 10.1093/sleep/zsad133) conducted a randomized crossover trial in 15 professional rugby players. Protocol: opportunity to nap for approximately 35 minutes between two training sessions on the same day. The nap group was compared with a wakefulness group.

Results:

• Peak power in a 6-second sprint: +157.6 W (p < 0.01, Cohen's d = 1.53 — large effect).
• Perceived exertion decreased by 1.2 units (p < 0.01, d = 1.72).
• Muscle soreness decreased (p = 0.04, d = 0.75 — moderate effect).
• Reaction time and alertness did not change significantly.

Does Napping Improve Aerobic Endurance?

Willmer et al. (Life Basel, 2023, DOI: 10.3390/life13061414) studied 12 athletes after a night of sleep deprivation. After a 30-minute nap (mean actual sleep — 23.2 min), alertness improved noticeably: the Pupil Unrest Index decreased from 7.9 to 4.2 (p = 0.003), and Karolinska Sleepiness Scale scores fell from 5.3 to 3.1 (p = 0.004).

However, time to exhaustion in the aerobic test did not change significantly (p = 0.367), nor did VO2max (p = 0.308). Conclusion: napping restores alertness but does not compensate for the aerobic performance deficit accumulated from poor nighttime sleep.

How Long and When to Nap?

The accumulated data suggest several practical guidelines. The 25–35-minute range is the most studied in RCTs: long enough to pass through N1–N2 light sleep stages, but not long enough to enter slow-wave sleep and wake with sleep inertia. The optimal time is during the post-lunch period, between two training sessions. The most pronounced effect is seen in athletes with two-a-day training schedules and in those experiencing subjective fatigue.