title: Sleep Extension before Sleep Loss: Effects on Performance and Neuromuscular Function.
abstract: This study aimed to investigate the effects of six nights of sleep extension on motor performance and associated neuromuscular function before and after one night of total sleep deprivation (TSD).
  
  
  
  Twelve healthy men participated in two experimental conditions (randomized crossover design): extended sleep (EXT, 9.8 ± 0.1 h time in bed) and habitual sleep (HAB, 8.2 ± 0.1 h time in bed). In each condition, subjects performed six nights of either EXT or HAB at home followed by an assessment of motor performance and neuromuscular function at baseline (D0) and after one night of TSD, i.e., 34-37 h of continuous wakefulness (D1). Maximal voluntary contractions with superimposed femoral nerve electrical and transcranial magnetic stimulations and stimulations on relaxed muscles were investigated before and after submaximal isometric knee extensor exercises performed until task failure.
  
  
  
  Time to exhaustion was longer in EXT compared with HAB (+3.9% ± 7.7% and +8.1% ± 12.3% at D0 and D1, respectively). Performance at D1 decreased from D0 similarly between conditions (-7.2% ± 5.6% and -3.7% ± 7.3% in HAB and EXT, respectively). At D1, the RPE during exercise was lower in EXT compared with HAB (-7.2% ± 7.5%) with no difference at D0. No difference was observed in voluntary activation between the two conditions.
  
  
  
  Six nights of sleep extension improved sustained contraction time to exhaustion, and this result cannot be explained by smaller reductions in voluntary activation, measured by both nerve and transcranial magnetic stimulation. The beneficial effect on motor performance in the EXT condition was likely due to reduced RPE after TSD.
authors.affiliation: 1Laboratoire Interuniversitaire de Biologie de la Motricité, Université de Lyon, Saint Etienne, FRANCE; 2Fatigue and Vigilance Unit, Armed Forces Biomedical Research Institute (IRBA), Brétigny sur Orge, FRANCE; 3University of Paris Descartes, VIFASOM (Vigilance Fatigue and Sleep), Sorbonne Paris Cité, Hôtel-Dieu, Paris EA7330, FRANCE; 4Extreme Environments Unit, Armed Forces Biomedical Research Institute (IRBA), Brétigny sur Orge, FRANCE; 5Sleep and Vigilance Center, University of Paris Descartes, Sorbonne Paris Cité, APHP, Hôtel-Dieu, Paris, FRANCE; and 6Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, CANADA.
authors.forename: Pierrick J
authors.initials: PJ
authors.lastname: Arnal
authors.forename: Thomas
authors.initials: T
authors.lastname: Lapole
authors.forename: Mégane
authors.initials: M
authors.lastname: Erblang
authors.forename: Mathias
authors.initials: M
authors.lastname: Guillard
authors.forename: Cyprien
authors.initials: C
authors.lastname: Bourrilhon
authors.forename: Damien
authors.initials: D
authors.lastname: Léger
authors.forename: Mounir
authors.initials: M
authors.lastname: Chennaoui
authors.forename: Guillaume Y
authors.initials: GY
authors.lastname: Millet
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004576:Electromyography; D005221:Fatigue / Q000503:physiopathology*; D006801:Humans; D008297:Male; D017286:Polysomnography; D011597:Psychomotor Performance / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D014851:Wakefulness