Energy contribution characteristics across different segments during a simulated rowing ergometer race in young trained rowers

To investigate the energy system contributions of rowers during a 2000-m ergometer simulation divided into four segments. Twelve Tier 2 rowers ( n = 12; 6 male and 6 female; age 17.0 ± 2.5 years; body mass 79.6 ± 7.7 kg; height 188.6 ± 8.7 cm; training experience 3.4 ± 1.6 years ) voluntarily participated in four 2000-m ergometer simulation trials. Participants were instructed to maintain a uniform, race-pace strategy (reverse J-shaped pacing). Unbeknownst to the athletes, trials were randomly terminated at 500-m, 1000-m, 1500-m, and 2000-m, with a minimum interval of 24 h between tests. Energy contributions were estimated from the fast component of oxygen debt (VO 2 pcr), accumulated blood lactate (△BLC), and VO 2 during test. Energy contributions were then calculated for the four 500-m segments. Four testing strategies showed good consistency ( p = 0.05, mean typical error: 0.8% to 4.4%). Relative W AER increased from500-m 2nd to 500-m 4th compared with the 500-m 1st (all p < 0.01), whereas W PCR and relative W PCR were highest during the 500-m 1st and remained lower thereafter (all p < 0.01). W BLC was also higher during the 500-m 1st than during subsequent segments. Females had higher relative W AER than males in 500-m 3rd ( p = 0.04, g = 1.16). Males showing higher relative W PCR than females in 500-m 3rd ( p = 0.01, g = 1.16). Aerobic metabolism predominated throughout the 2000 m race, but the relative energy system contributions varied substantially across segments, with greater anaerobic contribution during the start phase and greater aerobic contribution during the subsequent segments. Only limited sex differences were observed in this redistribution pattern.