Abstract

Observations were made every 4 h on 2 teams during 91 h 45 min of 5-a-side soccer to investigate stresses on players. Variables monitored were subjective fatigue, state anxiety, grip strength, heart rate, activity, urine protein concentration and liquid intake. Circadian functions were identified in all variables except protein urine as well as significant intercorrelations. Periodicities were consistent with arousal theory with troughs at about 0500-0600 h and crests at 1800 h to 2100 h. Group mean anxiety values increased between days as play was prolonged whilst significant decrements were found in activity, exercise heart rate and urine protein. Mean heart rate for the duration of play was 98 (± S.D. = 10) beats min^-1 and the work severity was considered light. Behavioural abnormalities as found by other investigators in chronically sleep deprived subjects were common during the final two nights.