To ensure the reliability and consistency of testing in rowing, biomechanical and physiological analyses are usually performed in a laboratory. The British Olympic Association has standardised the stroke frequency (SF) during each stage of the lactate threshold test in order to ensure consistency, although rowers are still allowed to ‘free pace’ in trials. This study investigated the gross and work efficiency of ergometer rowing at varying intensities and stroke frequencies. Ten experienced male rowers of mean (SD) age 23.5 (2.36) years, height 183.5 (7.63) cm, body mass 81.5 (4.0) kg, VO2MAX 5.1 (0.21) l.min-1, and lactate threshold 86.9% (2.8) of VO2MAX participated. Rowers completed an incremental step test to volitional failure. On subsequent days rowers performed 10 minutes of ergometer rowing at SFs of 24, 28, and 32 strokes per minute at intensities of; ‘no resistance’ (NR), 200W, 230W, 260W and 290W. Heart rate, VO2 and VCO2 were measured every 10 seconds, and post-exercise lactate concentrations were assayed from finger prick blood samples. Gross (work accomplished/energy expended) and work (work accomplished/energy expended above that in rowing without a load) efficiencies were calculated as described by Gaesser & Brooks (1975). Statistical analysis was performed using a 2-way ANOVA (P<0.05). There were significant differences (P<0.001) in VO2 between the three SFs during the NR trial and in plasma lactate (P<0.05) between the SFs of 24 and 32, but not between the heart rates. Oxygen consumption at the three SFs at power outputs of 200W, 230W, 260W and 290W were significantly different (P<0.001). A significant difference in gross efficiency (P<0.01) between SFs of 24 and 32 (P<0.01), and SFs of 28 and 32 (P<0.05) were identified. Significant differences in work efficiency between SFs of 24 and 32 (P<0.01), and between 24 and 28 (P<0.001) were also identified (Table 1). Significant differences (P0.05) in plasma lactate levels for power output or SF. Oxygen consumption, gross and work efficiency are affected by SF. To ensure that rowing ergometer tests are reliable, SF must remain consistent for all physiological experiments.
King's College London (2005) J Physiol 565P, PC25
Communications: Gross and work efficiency of club level rowers on a Concept II rowing ergometer
Donovan, Timothy Francis; Reilly, Thomas ; Cable, Nigel Timothy; MacLaren, Donald PM;
1. Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
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Table 1. Mean (± SEM) VO2 gross and mechanical efficiency during 10 min simulated rowing at SFs of 24 28 and 32 with and without resistance (*significant difference between 24spm and 32spm ** 28spm and 32spm † 24spm and 28spm)
Table 1. Mean (± SEM) VO2 gross and mechanical efficiency during 10 min simulated rowing at SFs of 24 28 and 32 with and without resistance (*significant difference between 24spm and 32spm ** 28spm and 32spm † 24spm and 28spm)
Where applicable, experiments conform with Society ethical requirements.