Abstract

Objectives: To assess the influence of moderate, acute weight loss on on-water rowing performance when aggressive nutritional recovery strategies were used in the two hours between weigh in and racing.

Methods: Competitive rowers (n  =  17) undertook three on-water 1800 m time trials under cool conditions (mean (SD) temperature 8.4 (2.0)°C), each separated by 48 hours. No weight limit was imposed for the first time trial—that is, unrestricted body mass (UNR₁). However, one of the remaining two trials followed a 4% loss in body mass in the previous 24 hours (WT_−4%). No weight limit was imposed for the other trial (UNR₂). Aggressive nutritional recovery strategies (WT_−4%, 2.3 g/kg carbohydrate, 34 mg/kg Na⁺, and 28.4 ml/kg fluid; UNR, ad libitum) were used in the first 90 minutes of the two hours between weigh in and performance trials.

Results: WT_−4% had only a small and statistically non-significant effect on the on-water time trial performance (mean 1.0 second, 95% confidence interval (CI) −0.9 to 2.8; p  =  0.29) compared with UNR. This was despite a significant decrease in plasma volume at the time of weigh in for WT_−4% compared with UNR (−9.2%, 95% CI −12.8% to −5.6%; p<0.001).

Conclusions: Acute weight loss of up to 4% over 24 hours, when combined with aggressive nutritional recovery strategies, can be undertaken with minimal impact on on-water rowing performance, at least in cool conditions.