A 90-min nap before small-sided games training increased total distance covered, reduced perceived fatigue, and enhanced mood, wellness, and cognitive alertness in professional soccer players.
Key Findings
Results
A 90-min nap resulted in significantly greater total distance covered during small-sided games compared to no-nap conditions.
15 professional male soccer players participated in a within-subjects counterbalanced design
Total distance covered was significantly greater under N90 vs. N0 (p = 0.002, Cohen's |d| = 0.96), representing a large effect size
Players had a mean age of 22.4 ± 1.2 years and estimated VO2max of 55.9 ± 2.8 mL·min-1·kg-1
Time-motion metrics were obtained via the FieldWiz GPS system throughout SSGs
Results
The 90-min nap condition was associated with lower pre-session resting heart rate compared to the no-nap condition.
Pre-session resting HR was significantly lower following N90 compared to N0 (p < 0.001, Cohen's |d| = 1.33), representing a large effect size
Relative exercise HR during SSGs was also reduced under N90 (p = 0.03, |d| = 0.33)
Exercise heart rate was continuously monitored throughout the SSGs sessions
Results
Post-SSGs blood lactate concentration and ratings of perceived exertion were lower following the 90-min nap condition.
Post-SSGs blood lactate concentration [La] was significantly lower following N90 vs. N0 (p = 0.015, Cohen's |d| = 0.71)
Ratings of perceived exertion (RPE) were significantly lower following N90 vs. N0 (p = 0.001, Cohen's |d| = 1.03), representing a large effect size
Both [La] and RPE were assessed post-SSGs in both conditions
Results
The 90-min nap led to higher vigor scores and lower Hooper index values (better wellness) compared to the no-nap condition.
Vigor scores were significantly higher following N90 vs. N0 (p = 0.003, Cohen's |d| = 1.01), representing a large effect size
Hooper index values (wellness status) were significantly lower following N90 vs. N0 (p = 0.02, Cohen's |d| = 0.59), indicating better wellness
Mood states and wellness were evaluated before each SSGs session using the Hooper index
Results
Cognitive reaction time was faster following the 90-min nap compared to the no-nap condition.
Reaction time on the Go/NoGo task was significantly faster following N90 vs. N0 (p = 0.02, |r| = 0.60), representing a large effect size
Cognitive performance was assessed using the Go/NoGo task before each SSGs session
The effect size metric reported for this outcome was a correlation coefficient (|r|) rather than Cohen's d
Methods
The study used a within-subjects counterbalanced design with nap monitoring via wearable technology and daytime sleepiness assessments.
Nap duration was 90 minutes and was monitored using a Fitbit Charge 6 wristband
Daytime sleepiness was assessed pre- and post-nap
The study involved 15 professional male soccer players completing two SSG sessions under N90 and N0 conditions
Counterbalanced design was used to control for order effects
What This Means
This research suggests that taking a 90-minute nap before soccer training can meaningfully improve how professional players perform and feel during small-sided game sessions. Players who napped covered more total distance during the games, had lower heart rates both at rest before the session and during exercise, and showed lower levels of blood lactate (a marker of physical fatigue) after the session. They also reported feeling less effort during the same activity, suggesting their bodies were working more efficiently.
Beyond physical performance, the nap also appeared to benefit mental and emotional states. Players who napped reported higher vigor, better overall wellness, and showed faster reaction times on a cognitive test before their training session. These improvements in mood, well-being, and mental sharpness suggest that a 90-minute nap does more than just reduce physical fatigue — it may prime athletes cognitively and emotionally for demanding training.
This research suggests that a structured 90-minute nap could serve as a practical, low-cost strategy — sometimes called an ergogenic aid — to help professional soccer players recover better and perform at a higher level during training. This is particularly relevant for players who may experience fatigue from demanding training schedules, travel, or disrupted nighttime sleep, as napping could serve as a supplementary recovery tool within a broader performance and wellness program.
Kerkeni M, Boukhris O, Kerkeni M, Ammar A, Husain W, Zmijewski P, et al.. (2026). Effects of a 90-Min Nap on Time-Motion Metrics and Psychophysiological Responses During Small-Sided Games in Professional Soccer Players.. Scandinavian journal of medicine & science in sports. https://doi.org/10.1111/sms.70193