Effects of partial sleep deprivation after prolonged exercise on metabolic responses and exercise performance on the following day

[PURPOSE]: We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [METHODS]: Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% [Formula: see text]) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00–7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% [Formula: see text]), and time to exhaustion (TTE) at 85% [Formula: see text] were evaluated. [RESULTS]: On day 2, neither the MVC nor [Formula: see text] during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [CONCLUSION]: A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.