Workload of water polo players following a phosphorus supplemented high carbohydrate meal -

Abstract

Phosphorus supplementation has been recommended as an ergogenic aid by previous studies some of which reported a significant improved cardiac capacity in athletes. The literature on the topic is however ambivalent, with as many studies finding no improvement in performance. Most of the studies researched the chronic effect following a loading period. The current study aimed to research the acute effect of phosphorus supplementation, taken concomitantly with a carbohydrate load. When a sample of 14 male water polo players was supplemented with 400 mg of phosphorus (P) concomitant with a glucose solution, they displayed a significant increase in heartrate difference between phosphorus and placebo during exercise (p0.001), yet supplementation left unaffected the exercise efficiency. The breathing rate per minute was unchanged, which may be interpreted as an improvement in VO2 max since the heart rate increase would have normally necessitated a higher breath count. This interpretation resonates with previous research on ergogenic effects of phosphorus which found no improvement in time trials but an increase in VO2 max. In our trial, we calculated the change in work efficiency while controlling for muscle glycogen by asking the participants to observe an overnight fast, and by depleting the remaining reserves through a 25 mins bike run before meal intake. We then measured the change in work output 3 hours after a 400Kcal glucose solution following a 20 mins run at a constant cadence of 85 rpm and an incremental power output protocol. It was a crossover design with a phosphorus intervention at a dose of 1 mg-kcal.