REF-1732 · Souabni et al., 2026 · Biology of Sport, · Paper · PubMed

In 12 high-level adolescent male basketball players at a training camp, a 60-min nap opportunity at 14:00 on five days in a row added sleep (24-h total 8.4 vs 7.7 h) without hurting the nights, and by day 5, not on day 1, they jumped higher (38.4 vs 35.3 cm) and moved faster in agility tests than after five days of seated rest; the RPE difference between conditions was not significant, in a small crossover. Read in full

Main caveat: 12 players, male, adolescent; performance tested on two days only per block; agility values shown only in a figure.
limited evidenceMeasured on highly trained to elite athletesRead in full

Souabni and colleagues tested whether napping on consecutive days does more than a single nap.

Twelve high-level male basketball players, aged about 16, did two five-day blocks during a training camp, in counterbalanced order with two days between: on each day of one block they had a 60-min nap opportunity at 14:00 in a dark quiet room, and on each day of the other they sat and rested for the same hour.

Days were standardised (breakfast 09:00, shooting session 10:00-11:30, lunch 12:30). Players slept a mean 40.35 min per nap opportunity, with nap sleep longer on days 3 and 4 than on day 1, and the naps raised 24-h total sleep (5-day mean 8.4 vs 7.7 h) without changing night sleep.

Wellness (Hooper) after the nap was better than after rest on every day, with the sleep quality, fatigue and soreness items improved. On day 1 the nap made no difference to any performance test, 90 min after waking.

By day 5 the nap block gave better offensive and defensive agility, higher repeated jumps and more jump power than the rest block, and jump height and power rose from day 1 to day 5 only with naps. RPE after the jump test fell from day 1 to day 5 within the nap block, but the nap and rest conditions did not differ significantly.

Total HRV power was higher after the nap than after rest; time-domain HRV did not differ. The authors conclude that the benefits appeared with repeated naps rather than a single one, and that the findings are preliminary.

Participants

n = 12 male basketball players, age 15.75 ± 0.62 y, height 1.82 ± 0.07 m, body mass 71.36 ± 12.75 kg, fat 16.49 ± 8.54%; 6 international-level; high-school students training 5 times a week (2 h) plus one match.
Habitual sleep over one week: 6.56 ± 0.81 h, efficiency 81.30 ± 5.31%; PSQI 4.67 ± 1.30; Morningness-Eveningness score 48.25 ± 9.14 (extreme chronotypes excluded); daytime sleepiness (CASQ) 37.08 ± 9.41.
Excluded: sleep disorders, habitual napping (≥ 1 nap a week), medication affecting sleep or HRV, nicotine, alcohol; caffeine-naive (< 80 mg/day), no caffeine during the study.

Protocol

Two 5-day conditions in randomised, counterbalanced order, separated by a 2-day washout without napping, "following normal sleep nights".
NAP: 60-min nap opportunity at 14:00 in a dark quiet room. CON: 60 min seated passive activity (reading, neutral television, cards).
Actigraphy (GT3X, non-dominant wrist) day and night, cross-checked with sleep diaries.
Hooper questionnaire and 5-min supine HRV before and immediately after each nap or rest, every day.
Days 1 and 5, 16:30 (90 min after waking): warm-up (5 min jog, 10 min dynamic stretching, five progressive sprints), then dribble control test (offensive agility), modified agility T-test (defensive agility), seated medicine-ball chest pass (upper-body power), six repeated countermovement jumps with 30 s rest (height and power, Optojump), RPE (Borg 6-20) after the jumps; same order each time, mean of three trials.
One familiarisation session (laboratory, instruments, nap room; no practice nap).

Key Results

OutcomeResult
Nap sleep, 5-day mean40.35 ± 16.59 min, efficiency 67.25 ± 27.65%, onset latency 8.43 ± 11.19 min; longer on days 3 and 4 than day 1 (p = 0.045, 0.025); about 33 min on day 1 (Discussion)
24-h total sleep, 5-day meanNAP 8.4 h vs CON 7.7 h, p = 0.003 (abstract: d = 0.40)
Night sleep during the blocksno significant difference on any day for time in bed, total sleep, efficiency or wake after sleep onset; onset latency shorter with naps on day 2 (p = 0.02)
Repeated jump height, day 5NAP 38.41 ± 6.86 vs CON 35.25 ± 6.96 cm, p = 0.005; NAP day 1 34.94 ± 7.02 cm (day 1 to 5 within NAP p = 0.007)
Repeated jump power, day 5NAP 41.66 ± 9.29 vs CON 36.90 ± 8.89 W/kg, p = 0.0001; interaction F(1,11) = 27.57
Offensive agility (dribble test)condition effect p = 0.011; day 1 no difference (p = 0.328); day 5 NAP better (p = 0.005); post hoc power 0.48
Defensive agility (T-test)condition effect p = 0.042; interaction p = 0.051; day 5 NAP better (p = 0.015)
Upper-body power (chest pass)no significant effect (condition p = 0.112)
RPE after jumpscondition p = 0.653 and interaction p = 0.197, not significant; within NAP day 1 14.17 ± 1.27 to day 5 11.83 ± 1.59 (p = 0.002); CON day 5 12.58 ± 1.78
Hooper global scorelower (better) after nap than after rest on all five days (p 0.0001-0.040)
HRVno condition difference for heart rate, SDNN, RMSSD, pNN50; total power higher after nap than rest (5-day mean, p = 0.033); stress index lower after than before the nap (p = 0.030)
Agility times are shown only in a figure; their values are not in the text.
The abstract's ranges (fatigue, soreness and RPE "decreased", 0.002 ≤ p ≤ 0.035, 0.28 ≤ d ≤ 2.10) pool several comparisons; for RPE the decrease is within the nap block over days, not against rest.

Practical Application

Over five days of a training camp, a daily 60-min nap opportunity added about 40 min of sleep a day and, by day 5, went with higher repeated jumps and faster agility than seated rest in adolescent basketball players; one nap on day 1 changed nothing. 12 players; no change in night sleep.
Against SYNTH-07: the 60-min opportunity (about 40 min slept) at 14:00 sits inside the guide's 20-90 min before 16:00, and night sleep was not harmed, as the guide states. Testing came 90 min after waking, so the study does not test the guide's 30 min awake.The players were habitual short sleepers (6.56 h) but slept normal nights during the study, so this is napping on top of a normal night in chronically short-sleeping teenagers, not the guide's single short night; it gives no direct test of the short-night trigger.
The benefit took days: performance did not differ on day 1, and the authors link the later gain to longer, less fragmented naps as the non-habitual nappers adapted. Inference, not tested here: an athlete who rarely naps may need several days of practice naps before judging whether naps help.
RPE did not differ significantly between napping and resting; the fall over the block was within the nap condition only.
Inference, not tested here: transfer to adults and to endurance sessions is by analogy; adult nap evidence is REF-1672 and REF-1673.

Limitations

12 players, male, adolescent; performance tested on two days only per block; agility values shown only in a figure.
A 2-day washout between blocks; the authors call for a longer one to control carryover.
Actigraphy cannot stage sleep; HRV was measured before and after the nap, not during it, and frequency-domain HRV indices are hard to interpret (the authors).
Offensive agility rests on low post hoc power (0.48, the authors); the defensive-agility interaction was not significant (p = 0.051).
Our reading: the control was seated rest with reading, television or cards, and napping cannot be blinded.
No funding; no conflicts of interest declared.
How this entry was checked and changed
Why this level

a crossover of 12 (under the 15 a crossover needs for B+); the performance outcomes carry the claim, so the HRV results (markers) do not lower it