ABSTRACT
The purpose of this study was to examine energy expenditure of swimmers during high volume training (17.5 ±1.0 km-day–1) using the doubly labeled water method. Five world-ranked female swimmers were administered a dose of 2H218O and monitored for nine days. Day five was a rest day from swimming training, while the other days consisted of two training sessions per day, lasting a total of five to six hours. Resting energy expenditure (REE) was measured on a non-training day. Isotopic enrichment and decay rates were determined from saliva samples taken when the subjects first awoke. Isotopic decay constants and total energy expenditure were calculated using the two- point method. Food quotients, calculated from three days of dietary recall, averaged 0. 919 (range of 0.88 to 0.94) and were used to convert CO2 production to total energy expenditure (TEE). There were no changes in total body weight or body composition (from skinfold measurements) over the measurement period and therefore, no changes in the pool size in which the isotopes were distributed. REE and TEE were 7.70 ± 0.49 and 20.81 ± 1.19 MJ·day–1, respectively. The results of this investigation describe the total energy demand of high volume swimming training, which may be used to address the dietary concerns of the competitive swimming athlete.
