Seasonal Changes in the Peak-to-Sustained Power Profile of Elite Sprint Kayakers

This study examined whether training periodization is associated with a systematic shift in the anaerobic performance profile of elite Czech sprint kayakers, assessed through seasonal (winter-summer) changes in Wingate-derived anaerobic performance, blood lactate response, and body composition analysis. Twenty-five sprint kayakers (10 women, 15 men) completed a 30-s upper-body Wingate test and anthropometric assessment during the winter preparatory period and again during the summer competition period. From winter to summer, peak power decreased by 37.3 ± 34.9 W (p < 0.001, dz = -1.07) and by 0.31 ± 0.43 W·kg^-1 (p = 0.001, dz = -0.73), whereas mean power increased by 14.8 ± 24.1 W (p = 0.005, dz = 0.61) and by 0.30 ± 0.28 W·kg^-1 (p < 0.001, dz = 1.07). Stroke cadence increased by 2.8 ± 3.7 rpm (p = 0.001), while body mass decreased by 1.3 ± 1.5 kg (p < 0.001) and skinfold-derived body fat decreased by 0.9 ± 1.5% (p = 0.006); peak blood lactate did not differ significantly between seasons (p = 0.228). The pattern was broadly similar in men and women, although the increase in absolute mean power did not reach significance in women (p = 0.087) despite a significant increase in relative mean power (p = 0.002). Peak power was lower and mean power was higher in the competitive phase than in the preparatory phase, indicating a shift in the anaerobic power profile toward sustained output. Because this study compared a single preparatory-competitive pair without a repeated macrocycle or a non-training control condition, this pattern is best interpreted as a phase-associated difference consistent with seasonal training emphasis, rather than as a demonstrated causal effect of training. This shift, coinciding with the transition from the winter preparatory to the summer competition phase, is the central finding of the study; monitoring an athlete's position along this continuum may help coaches individualise periodization and interpret single-time-point Wingate results.