Physiological responses that account for the increased power output in speed skating using klapskates

Abstract

The present study investigates which physiological sources support the increase in mechanical power output (W out) that can be obtained using klapskates in speed skating. It was hypothesized that the increase in W out could be achieved through an increase in gross efficiency or an increase in aerobic power (W aer). Six speed skaters performed a submaximal and maximal 1,600-m skating test with both klapskates and conventional skates, to measure gross efficiency and maximal W aer during speed skating. The rate of oxygen uptake (VO2) and post-exercise blood lactate concentrations ([La]) were measured and video recordings were made. W aer was calculated from VO2. W out was derived from the power needed to overcome air and ice friction. Gross efficiency was calculated as the ratio of W out and W aer. In the maximal tests, the subjects skated faster with klapskates compared to conventional skates (10.0 vs 9.6 m x s(-1)). They sustained the resulting higher W out with klapskates with an equal VO2. [La] was, however, 1.7 mmol x l(-1) higher when klapskates were used, which might reflect an increase in anaerobic power. During the submaximal tests the skaters generated equal W out with both types of skate. Although not statistically significant, VO2 and W aer were, on average, lower when klapskates were used compared to conventional skates [mean (SD) 0.3 (0.43) l x min(-1), 105 (143) W]. Despite the lack of a statistically significant difference in W aer, gross efficiency was shown to be significantly higher with klapskates compared to conventional skates (16.3% vs 14.8%, P = 0.02). We conclude that the increase in W out when the subjects were using klapskates could be explained by an increase in gross efficiency rather than an increase in W aer.

Capturing the Complex Relationship Between Internal and External Training Load: A Data-Driven Approach

“…28 Moreover, the heart rate intensities we observed corresponded to the intensity that is regularly used by speed skaters during their endurance training (∼90%-95% HR max ). 29 By using 2D KDE plots, internal and external load can also be directly compared between 2 types of training sessions, by subtracting their density estimates (Figure 4). Such visualizations provide additional and detailed insights into the (subtle) differences in training load between training session types.…”

How Hinge Positioning in Cross-Country Ski Bindings Affect Exercise Efficiency, Cycle Characteristics and Muscle Coordination during Submaximal Roller Skiing

“…This system was found to limit the plantar flexion, resulting in premature termination of the push-off. With the klapskate this lever arm was reduced, allowing for plantar flexion with the skate blade remaining flat whilst gliding on the ice and thereby increasing the effectiveness of the push-off [ 2 , 3 , 4 ]. As a result, skating velocity increased up to 5%, which was made possible due to an increase in mechanical power output generated across the ankle, knee and hip joints [ 2 , 4 ].…”

“…These observed changes in kinematic and kinetic variables, leading to a higher mean power output, can be apprehended by increasing the work delivery by muscle-tendons as well as by a higher efficiency in the transformation of metabolic energy to power output [ 2 ]. This was later exemplified by an increase in gross efficiency [ 3 ].…”