REF-384 · Skein et al., 2011 / Fullagar et al., 2015 · Medicine & Science in Sports & Exercise, · Paper · PubMed
Intermittent-Sprint Performance and Muscle Glycogen after 30 h of Sleep Deprivation
In 10 team-sport athletes a sleepless night slowed sprints (2.78 vs 2.74 s), cut self-paced distance, lowered muscle glycogen (209 vs 274 mmol/kg dw) and voluntary force/activation, and worsened mood; RPE was unchanged
Participants (Skein 2011)
n=10 male team-sport athletes.
Protocol
A single-day baseline session, then two two-day experimental trials: day 1 and day 2 separated by either a normal night's sleep (CONT1, CONT2) or no sleep (SDEP1, SDEP2) — about 30 h awake before SDEP2.
Each session: 30-min graded exercise run + 50-min intermittent-sprint protocol with a 15-m maximal sprint every minute and self-paced bouts of varying intensity.
Muscle biopsies before and after exercise at baseline and before exercise on day 2 of each trial.
Measured: voluntary force and activation of the right quadriceps, nude mass, HR, core temperature, capillary lactate and glucose, RPE, and a modified POMS mood questionnaire.
Key Findings
Mean sprint time was slower on SDEP2 (2.78 ± 0.17 s) than on SDEP1 (2.70 ± 0.16 s) and CONT2 (2.74 ± 0.15 s), P < 0.05.
Self-paced distance was lower on SDEP2 in the first 10 min (vs SDEP1) and the final 10 min (vs CONT2), P < 0.05.
Pre-exercise muscle glycogen was lower on SDEP2 (209 ± 60 mmol/kg dw) than CONT2 (274 ± 54), P = 0.05.
Voluntary force and activation fell on day 2 in both conditions, but were lower on SDEP2 than CONT2 (P < 0.05).
Sleep loss did NOT change RPE, but worsened POMS mood ratings (P < 0.05).
Authors' conclusion: sleep loss, with the associated lower muscle glycogen and greater perceptual stress, reduced sprint performance and slowed pacing during intermittent-sprint exercise.
The abstract does not report perceived muscle soreness, tightness, creatine kinase, cognitive tests or hormones.
Mechanism
Measured: lower pre-exercise glycogen, lower voluntary force and activation (a neuromuscular component), worse mood — with RPE unchanged.
Inference, not tested here: lower glycogen after a sleepless night is consistent with poorer overnight resynthesis and/or greater energy use while awake; the abstract does not identify the cause.
Practical Application
In 10 male team-sport athletes, 30 h without sleep before a second day of intermittent-sprint running slowed the mean 15-m sprint (2.78 vs 2.74 s with normal sleep), cut self-paced distance, lowered pre-exercise muscle glycogen (209 vs 274 mmol/kg dw) and reduced voluntary force and activation more than a normal night did, and worsened mood — while RPE was unchanged. So after a sleepless night expect less output and slower pacing at the same perceived effort; RPE will not warn you, and the deficit is partly fuel (glycogen) and partly neuromuscular.
Inference, not tested: on the day after a very short night, a key session is better swapped for lower-intensity work, and carbohydrate intake should not be cut — the glycogen finding argues for eating normally or more, not less.
Limitations
Skein: n=10, male team-sport athletes, a single 30-h total deprivation — not partial restriction over several nights.
Running-based intermittent-sprint protocol; transfer to cycling or long steady endurance is inference.
Fullagar 2015 is a narrative review named in the byline; no identifier is on file and none of its content is retained here as evidence.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: crossover, n=10
Content correction 2026-09-27
"Perceived soreness +20-30% at 24 h", "CK elevated longer", "perceived tightness higher", "cognitive performance impaired", "GH/IGF-1 reduced, cortisol elevated", "Fullagar: <6 h/night raises tightness and slows CK/DOMS recovery" -> none of this is in the Skein abstract, which reports sprint time, self-paced distance, muscle glycogen, voluntary force/activation, RPE and POMS; removed. Title changed to the paper's own.
"n=11" -> n=10 male team-sport athletes.
House advice ("sleep is the #1 muscle tone reducer", "8-9 h", "20-90 min naps restore GH pulsatility") -> not from the paper; removed. Added the abstract's numbers (sprint 2.78 vs 2.74 s; glycogen 209 vs 274 mmol/kg dw; RPE unaffected).
Level B+ -> B (crossover, n=10); Tier 2-3 -> Tier 2 (team-sport athletes).
Resync 2026-09-28: Cross-ref labelled REF-183 'sleep basics' though it is repeated-sprint training in hypoxia -> line removed.