Effects of two nights of sleep deprivation on executive function and central and peripheral fatigue during maximal voluntary contraction lasting 60s

•Two nights of sleep deprivation impaired mood and increased heart rate variability in young men.•Sleep deprivation worsened attention and inhibitory control during the go/no-go task.•Sleep deprivation reduced maximal voluntary contraction force (MVC) (but not maximal rate of torque development) of knee extensor muscles.•Sleep deprivation decreased motor performance during the MVC-60 s, however did not reduce central activation ratio immediately after the MVC-60 s. The current study aimed at assessing the effect of a trial of two nights of sleep deprivation (SDT) on mood, sleepiness, motivation and cognitive and motor performance. Thirty-six healthy young and physically active adult men (17 in the control group and 19 in the SDT group) completed a 48-h control or 48-h SDT. For the SDT, participants did not sleep for 48 h. Executive function (attention and inhibitory control) in the Go/No-Go and Stroop tests, mood, sleepiness, motivation, heart rate variability (HRV), motor performance in a hand grip strength test, and 60-s maximal isometric contraction (MVC-60 s) of knee extension were evaluated at 9–11 am on consecutive days 1, 2, and 3. One night of sleep deprivation increased sleepiness, decreased mood, motivation and motor endurance but did not affect executive function (as measured in the Stroop and Go/No-Go tests), the MVC for hand and leg knee extensor muscles, and peripheral motor fatigue in the leg MVC-60 s task. However, the central activation ratio (CAR) decreased significantly during the MVC-60 s. The SDT significantly contributed to the decrease in these functions. That is, the SDT reduced executive function (increased reaction time during Go/No-Go test), MVC of knee extension, and the CAR before and after the MVC-60 s. By contrast, the SDT did not increase CAR immediately after the MVC-60 s and did not decrease the rate of torque development (RTD). The SDT significantly impaired mood, motivation and increased sleepiness and HRV, reduced MVC of knee extensor muscles (but not RTD) and motor performance during the MVC-60 s and worsened executive function (attention and inhibitory control) only during the Go/No-Go task. However, the SDT did not reduce hand grip strength and CAR immediately after the MVC-60 s of knee extensor muscles.