Moderate levels of hypohydration impairs bowling accuracy but not bowling velocity in skilled cricket players

The effects of exercise-induced hypohydration on the motor skill performance of cricket bowling was examined in seven medium-fast bowlers who performed a random order of two experimental trials. Trials consisted of a bowling test (36 deliveries; PREBOWL) in a thermoneutral (16+/-2 degrees C) environment followed by approximately 1 hr of intermittent exercise in a heated environment (28+/-2 degrees C) and a further thermoneutral bowling test (36 deliveries; POSTBOWL). During one trial fluid intake was restricted (HYPO) whereas in the other, subjects were forced to drink in an effort to maintain euhydration (EUH). During all bowling tests subjects were provided with a fixed target on a cricket pitch and the line, length, and velocity of each delivery was determined. Pre-trial hydration status was confirmed by similar body mass (BM; 89.5+/-13.7 vs. 88.9+/-13.4 kg) and haemoglobin concentration (15.0+/-0.8 vs. 14.8+/-0.8 g.100 ml(-1) for EUH and HYPO, respectively). BM loss was greater in HYPO than EUH (2.48+/-0.58 vs. 0.46+/-0.45 kg). Accordingly, the resultant hypohydration was higher after HYPO than EUH (2.78+/-0.49 vs. 0.47+/-0.41% of BM). Whereas HYPO had no effect on bowling velocity (102+/-4 vs. 105+/-8 km x h(-1)), univariate analyses revealed independent differences for both bowling line (2.9+/-0.5 vs 3.4+/-0.6, P<0.01) and length (2.9+/-0.5 vs 3.4+/-0.6, P<0.01) of delivery after HYPO. We conclude that moderate (-2.8% of BM) exercise-induced hypohydration has minimal effect on maximal bowling velocity, but there is a detrimental effect on skilled motor performance in well-trained subjects.