Effects of one-night of partial sleep loss on the circadian rhythm of temperature, subjective tiredness, alertness, and standing broad jump performance; is there a sex difference?

Maximal gross-muscular performance shows a daily variation in adult males, however, effects of sleep loss on circadian rhythms of gross-muscular tasks with a high skill element such as the standing broad jump is less well established, and differences between biological sex may exist. Thirty-one males and 24 females volunteered. Participants were familiarised with tests before completing two conditions i) Normal (N) retires at 23:30, rising at 07:30 h the night before testing, and ii) Sleep deprivation (SD) retiring at 03:00, rising at 07:30 h, administered in a randomised counterbalanced-fashion. Participants having had 8- or 4.5-h opportunity to sleep, entered the laboratory at 08:00 h and sublingual temperatures, tiredness, and alertness were measured. Thereafter, volunteers completed a warm-up (3 jumps at 40, 60, and 80% max-effort) and then performed jumps. This schedule was replicated at 12:00, 16:00, 20:00, 24:00, and 04:00 h on the same day. Participants were more tired and less alert in the partial sleep deprivation condition, and time-of-day effects were evident in all variables with peaks in jump length coinciding with temperature and alertness (Ф15:44-18:24 h). Females, however, showed a preference for an ~1 h earlier peak in tiredness (mediated in the SD rather than N), with a lower mesor and/or amplitudes in alertness and jump performance than males. The results of the current investigation have important implications for athletes, particularly females suffering sleep loss, regarding strategies to cope with early peaks in tiredness and physical training demands.