This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n = 21, VO2max 4.1 ± 0.7 L/min, training experience 2.7 ± 1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscle-oxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (−.5 to −.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (−.4 to −.7) with 200- and 1000-m performance. In addition, trivial to large correlations (−.11 to −.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (P < .001), whereas 85% of the unadjusted variance in 1000-m TT performance was explained by VO2max and deoxyhemoglobin (P < .001). The current findings show that well-trained junior sprint kayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation.
Thiago Oliveira Borges, Ben Dascombe, Nicola Bullock, and Aaron J. Coutts
Thiago Oliveira Borges, Nicola Bullock, David Aitken, and Aaron J. Coutts
This study compared 3 commercially available ergometers for within- and between-brands difference to a first-principle calibration rig.
All ergometers underestimated true mean power, with errors of 27.6% ± 3.7%, 4.5% ± 3.5%, and 22.5% ± 1.9% for the KayakPro, WEBA, and Dansprint, respectively. Within-brand ergometer power differences ranged from 17 ± 9 to 22 ± 11 W for the KayakPro, 3 ± 4 to 4 ± 4 W for the WEBA, and 5 ± 3 to 5 ± 4 W for the Dansprint. The linear-regression analysis showed that most kayak ergometers have a stable coefficient of variation (0.9–1.7%) with a moderate effect size.
Taken collectively, these findings show that different ergometers present inconsistent outcomes. Therefore, we suggest that athlete testing be conducted on the same ergometer brand, preferably the same ergometer. Optimally, that ergometer should be calibrated using a first-principle device before any athlete testing block.
Thiago Oliveira Borges, Nicola Bullock, David Aitken, Gregory R. Cox, and Aaron J. Coutts
Purpose: To compare the metabolic cost of paddling on different commercially available kayak ergometers using a standardized kayak incremental exercise protocol. Methods: Six male sprint kayak athletes undertook an incremental exercise protocol on 3 different kayak ergometers utilizing a randomized counterbalanced pair-matched design. Results: Mean maximal aerobic power on the WEBA ergometer (265  W) was significantly higher than on the Dansprint (238  W) and KayakPro® (247  W, P < .01, effect size [ES] = 0.80). At the fifth stage, absolute oxygen consumption on the WEBA (3.82 [0.25] L·min−1) was significantly lower (P < 0.05, ES = 0.20) than KayakPro and Dansprint (4.10 [0.28] and 4.08 [0.27] L·min−1, respectively). Blood lactate concentration response at the sixth stage was significantly lower for the WEBA (3.5 [0.8] mmol·L−1), compared with KayakPro and Dansprint (5.4 [1.2] and 5.6 [1.5] mmol·L−1, P = .012, ES = 0.20). Stroke rate was significantly higher, without any effect of pacing during the submaximal stages for the Dansprint, compared with the WEBA (P < .001, ES = 0.28) and KayakPro (P < .001, ES = 0.38). A pacing effect was present at the maximal stage for all ergometers. Conclusions: This study demonstrated that paddling on different kayak ergometers when controlling power output elicits different metabolic and work outputs. It is recommended that scientists and coaches avoid testing on different ergometers and regularly calibrate these devices. Moreover, when an ergometer has been calibrated against a first principle device, it is necessary to consider calibration of various drag settings, due to their impact on stroke rate. Further research should explore the relationship between drag settings and stroke rate.
Braulio C. Mendonça, Antônio C. Oliveira, José Jean O. Toscano, Alan G. Knuth, Thiago T. Borges, Deborah C. Malta, Danielle K. Cruz, and Pedro C. Hallal
Evaluation studies of large scale physical activity promotion programs are rare in Latin America. The aim of the current study was to evaluate the association between various forms of exposure to Academia da Cidade (PAC), a professionally supervised intervention in Aracaju (Brazil), and leisure-time physical activity (LTPA).
A population-based study including 2267 adults was carried out. LTPA was assessed using the long version of the International Physical Activity Questionnaire, and a cut-off of 150 minutes per week was used in the analyses.
In fully adjusted models, having ever heard about PAC was related to an odds of 1.8 (95% CI 1.4−2.2) for reaching the 150-minutes per week LTPA threshold. Equivalent odds ratios were 1.6 (95% CI 1.1−2.3) for having ever seen a PAC class, 14.3 (95% CI 12.3−16.4) for current and 4.0 (95% CI 1.4−11.3) for past PAC participation.
Different sources of exposure to PAC were significantly associated with LTPA, which may suggest that professionally-supervised community classes offered for free may be a successful alternative for promoting physical activity in Brazil. If PAC happens to be expanded to other Brazilian areas, intervention studies may be carried out to evaluate its effectiveness.