The influence of carbohydrate-electrolyte ingestion on soccer skill performance.Med Sci Sports Exerc. 2007 Nov; 39(11):1969-76.MS
To investigate the effect of ingesting a carbohydrate-electrolyte solution (CHO-E), in subjects with reduced carbohydrate stores, during an intermittent shuttle running test (LIST) on soccer passing (LSPT) and shooting (LSST) performance.
Sixteen healthy male university soccer players ingested either a 6.4% CHO-E or placebo (PLA) solution during 90 min of the LIST (5 mL x kg(-1) BM before and 2 mL x kg(-1) BM every 15 min of exercise), in a double-blind, randomized, crossover design, with each trial separated by at least 7 d. On the evening before the main trial (17:00 h), subjects performed the glycogen-reducing cycling exercise (approximately 80 min at 70% VO2max). They were then fed a low-carbohydrate evening meal and reported to the laboratory the following morning after a 10-h fast. Blood was collected at rest and after every 30 min of exercise; skill tests were performed before and after the LIST.
The change in mean LSST performance from pre- to post-LIST was better in the CHO-E trial (11 +/- 45 vs -16 +/- 42%; P < 0.01) but not significantly different for the LSPT performance (-1 +/- 10% (CHO-E) vs -6 +/- 13% (PLA), P = 0.13). Sprint performance during the LIST was quicker in the CHO-E trial (2.50 +/- 0.13 vs 2.53 +/- 0.13 s, P < 0.01). Plasma glucose was higher in the CHO-E trial after 90 min of exercise (5.2 +/- 0.3 vs 3.9 +/- 0.4 mM, P < 0.01).
Ingestion of a carbohydrate-electrolyte solution during exercise enabled subjects with compromised glycogen stores to better maintain skill and sprint performance than when ingesting fluid alone.