The aim of the present study was to determine the effect of different nap opportunity durations on short-term maximal performance, attention, feelings, muscle soreness, fatigue, stress and sleep. Twenty physically active men (age: 21.1 ± 3.6 years, height: 176.4 ± 5.7 cm, body-mass: 72 ± 10.8 kg) performed the 5-jump and the digit-cancellation (i.e., attention) tests after four randomized nap opportunity conditions: no-nap opportunity (N0), 25 min of nap opportunity (N25), 35 min of nap opportunity (N35) and 45 min of nap opportunity (N45).
Subjective measurement of feelings, muscle soreness, fatigue, stress and sleep were performed during each test session. Compared to N0, there was a significant improvement of the 5-jump performance during N35 (Δ = +3.5%, p < .01) and N45 (Δ = +3.7%, p < .01). Attention was also better after N45 compared to N0 (Δ = +7.5%, p < .05). Fatigue, sleep and stress scores were significantly lower after N25, N35 and N45 compared to N0 (p < .05). However, no-significant effect of naps durations on feelings and fatigue scores was observed.
A nap opportunity has a beneficial effect on physical performance and attention with better results observed for naps ≥35 min.