Longitudinal assessment of the effects of field-hockey training on repeated sprint ability.

Repeated-sprint ability is thought to be an important fitness component of team sports. However, little is known about the effect sport-specific training has on this fitness component. Therefore, the purpose of this study was to investigate the effects of field-hockey specific training on repeated-sprint ability, plasma hypoxanthine (Hx) concentration and other blood parameters in 18 elite female field-hockey players. All subjects performed a repeated-sprint ability test on a cycle ergometer (5 x 6-sec maximal sprints every 30 secs) before and after seven weeks of training, designed to improve repeated-sprint ability. Following training, there was a significant (P< 0.05) increase in absolute total work (20.73+/-2.00 to 21.15+/-2.07 kJ, mean+/-SD). However, there was no significant change in total work when expressed per kg of body mass (341.3+/-16.4 to 345.5+/-18.8 J x kg(-1)). In addition, training resulted in a significant (P< 0.05) decrease in change values (peak-rest values) for Hx (8.2+/-3.8 to 5.5+/-2.7 micromol x L(-1)) and hydrogen ion concentration (22.8+/-5.2 to 19.1+/-5.1 nmol x L(-1)). The significant increase in absolute total work following seven weeks of field-hockey specific training was most likely due to an increase in lean muscle mass. The significant decrease in plasma Hx concentration (post-test minus rest values) following seven weeks of field hockey-specific training provides evidence that Hx production and/or efflux from the muscle are reduced. Therefore, one adaptation of sport-specific repeated-sprint training may be to conserve the purine nucleotide pool.