Dados do Trabalho

Título

Is the cycling sprint performance at isolinear and isovelocity interchangeable?

Introdução e Objetivo

The maximal power and capacity of anaerobic energy output can be assessed by work and mechanical force/power during a sprint on the cycle ergometer. In cycling, the peak power output is a very important parameter, because it has been shown to predict sprint performance, which could be obtained by all-out efforts lasting around 5 to 10-s. This study aimed to compare the sprint performance-derived parameters (i.e., maximal torque, cadence, and power-output; and the optimal cadence) measured by means of isolinear (ISOLIN) and isovelocity (ISOVEL) cycling modes.

Casuística e Método

Twenty health male performed several 7-s all-out sprints on an electromagnetically braked cycle ergometer (Lode Excalibur Sport, Groningen, Netherlands). Lode cycling ergometer is able to operate in different modes, such as pedaling rate dependent mode (linear mode - ISOLIN) and isokinetic mode (ISOVEL). Thus, the participants performed the sprints as follow: two at the ISOLIN mode and six at the ISOVEL mode (at 90, 110, 120, 130, 150, and 180 rpm) with 3 min of recovery among them. All sprint were performed with flying start by pedaling at 50 W for 30s at the preferred cadence. The torque (T), velocity/cadence (C), and power-output (PO) data were measured at the cranks with 180 data points for every pedal revolution (PFM Lode Excalibur Ergometer). These data were filtered to obtain the peak values for each pedal revolution for analysis. The sprints within each mode were modeled by a linear function to extrapolate maximal C (CMAX) and T (TMAX), and by a quadratic function to extrapolate the apex defined as maximal power output (PMAX) and its respective cadence (COPT). For data analysis, paired t-tests and Pearson correlation coefficient, with statistical significance set as p <0.05 were used.

Resultados

The measures from the P-C relationship were not different between ISOLIN and ISOVEL modes (PMAX: 969 ± 145 vs. 991 ± 133 W, respectively). Although significant differences were detected in the T-C relationship, TMAX was greater (p = 0.006) at ISOLIN than ISOVEL (159 ± 21 vs. 146 ± 19 N.m, respectively). On the other hand, CMAX was higher at ISOVEL than ISOLIN (255 ± 38 vs. 237 ± 24 rpm, respectively; p <0.001). Significant correlations were found for all variables, such as PMAX (r = 0.89), TMAX (r = 0.60), CMAX (r = 0.77) and COPT (r = 0.50).

Discussão

The main findings were that the estimated CMAX were lower for ISOLIN mode compared to ISOVEL, and on the other hand, COPT was not significantly different between the modes (difference <1 rpm). Additionally, ISOLIN mode did not use torque factor, and the standardized flying start between the modes meant that ISOLIN did not make it possible to achieve CMAX extrapolation similar to ISOVEL. However, no significant differences occurred between COPT, which would be a determining factor for training and performance. Thus, the standardization of the beginning of sprints in the different modes allowed for supposed interchangeability regarding COPT and PMAX, with the advantage for ISOLIN mode, which could be performed through only a single 7-s sprint.

Conclusão

Using the P-C relationship, PMAX and COPT could be detected similarly between the two sprint modes (ISOLIN and ISOVEL). Therefore, the interchangeability of the modes must be extrapolated to different populations, situations, and conditions to better understand the implications of these similarities and differences between the modes.