Method-Induced Differences of Energy Contributions in Women's Kayaking.

CONTEXT: Different relative aerobic energy contribution (WAER%) has been reported for the 2 women's Olympic kayaking disciplines (ie, 200 and 500 m). PURPOSE: To investigate whether the adopted method of energy calculation influences the value of WAER% during kayaking time trials. METHODS: Eleven adolescent female kayakers (age 14 ± 1 y, height 172 ± 4 cm, body mass 65.4 ± 4.2 kg, VO2peak 42.6 ± 4.9 mL·min-1·kg-1, training experience 1.5 ± 0.3 y) volunteered to participate in 1 incremental exercise test and 2 time trials (40 and 120 s) on the kayak ergometer. A portable spirometric system was used to measure gas metabolism. Capillary blood was taken from the ear lobe during and after the tests and analyzed for lactate afterward. The method of modified maximal accumulated oxygen deficit (m-MAOD) and the method based on the fast component of oxygen-uptake off-kinetics (PCr-La-O2) were used to calculate the energy contributions. RESULTS: The anaerobic energy portions from m-MAOD were lower than those from PCr-La-O2 in the 40-s (41.9 ± 8.8 vs 52.8 ± 4.0 kJ, P > .05) and 120-s (64.1 ± 27.9 vs 68.2 ± 10.0 kJ, P > .05) time trials, which induced differences of WAER% between m-MAOD and PCr-La-O2 (36.0% vs 30.0% in 40 s, P > .05; 60.9% vs 57.5% in 120 s, P > .05). CONCLUSIONS: The reported different WAER% in women's Olympic kayaking could be partly attributed to the adopted method of energy calculation (ie, m-MAOD vs PCr-La-O2). A fixed method of energy calculation is recommended during the longitudinal assessment on the relative energy contribution in women's Olympic kayaking.

Musical agency reduces perceived exertion during strenuous physical performance.

Music is known to be capable of reducing perceived exertion during strenuous physical activity. The current interpretation of this modulating effect of music is that music may be perceived as a diversion from unpleasant proprioceptive sensations that go along with exhaustion. Here we investigated the effects of music on perceived exertion during a physically strenuous task, varying musical agency, a task that relies on the experience of body proprioception, rather than simply diverting from it. For this we measured psychologically indicated exertion during physical workout with and without musical agency while simultaneously acquiring metabolic values with spirometry. Results showed that musical agency significantly decreased perceived exertion during workout, indicating that musical agency may actually facilitate physically strenuous activities. This indicates that the positive effect of music on perceived exertion cannot always be explained by an effect of diversion from proprioceptive feedback. Furthermore, this finding suggests that the down-modulating effect of musical agency on perceived exertion may be a previously unacknowledged driving force for the development of music in humans: making music makes strenuous physical activities less exhausting.