Physiological and performance effects of carbohydrate gels consumed prior to the extra-time period of prolonged simulated soccer match-play

Objectives: The physiological and performance effects of carbohydrate-electrolyte gels consumed before the 30 min extra-time period of prolonged soccer-specific exercise were investigated.

Design: Randomised, double-blind, crossover.

Methods: Eight English Premier League academy soccer players performed 120 min of soccer-specific exercise on two occasions while consuming fluid-electrolyte beverages before exercise, at half-time and 90 min. Carbohydrate-electrolyte (0.7 ± 0.1 g·kg-1 BM) or energy-free placebo gels were consumed ~5 min before extra-time. Blood samples were taken before exercise, at half-time and every 15 min during exercise. Physical (15-m and 30-m sprint speed, 30-m sprint maintenance and countermovement jump height) and technical (soccer dribbling) performance was assessed throughout each trial.

Results: Carbohydrate-electrolyte gels improved dribbling precision (+29 ± 20%) and raised blood glucose concentrations by 0.7 ± 0.8 mmol·l-1 during extra-time (both p < 0.01). Supplementation did not affect sprint velocities (15-m and 30-m), 30-m sprint maintenance or dribbling speed as reductions compared to 0-15 min values occurred at 105-120 min irrespective of trial (all p < 0.05). Plasma osmolality and blood sodium concentrations increased post-exercise versus the opening 15 min (p < 0.05) but no effect of supplementation existed. Selected markers of physical performance (jump height, 30-m sprint velocity and 30-m repeated sprint maintenance) also reduced by >3% during half-time (all p < 0.05).

Conclusions: Carbohydrate-electrolyte gel ingestion raised blood glucose concentrations and improved dribbling performance during the extra-time period of simulated soccer match-play. Supplementation did not attenuate reductions in physical performance and hydration status that occurred during extra-time.