Performance Effects of Video- and Sensor-Based Feedback for Implementing a Terrain-Specific Micropacing Strategy in...

To investigate the performance effects of video- and sensor-based feedback for implementing a terrain-specific micropacing strategy in cross-country (XC) skiing.

Following a simulated 10-km skating time trial (Race1) on snow, 26 national-level male XC skiers were randomly allocated into an intervention (n = 14) or control group (n = 12), before repeating the race (Race2) 2 days later. Between races, intervention received video- and sensor-based feedback through a theoretical lecture and a practical training session aiming to implement a terrain-specific micropacing strategy focusing on active power production over designated hilltops to save time in the subsequent downhill. The control group only received their overall results and performed a training session with matched training load.

From Race1 to Race2, the intervention group increased the total variation of chest acceleration on all hilltops (P < .001) and reduced time compared with the control group in a specifically targeted downhill segment (mean group difference: -0.55 s; 95% confidence interval [CI], -0.9 to -0.19 s; P = .003), as well as in overall time spent in downhill (-14.4 s; 95% CI, -21.4 to -7.4 s; P < .001) and flat terrain (-6.5 s; 95% CI, -11.0 to -1.9 s; P = .006). No between-groups differences were found for either overall uphill terrain (-9.3 s; 95% CI, -31.2 to 13.2 s; P = .426) or total race time (-32.2 s; 95% CI, -100.2 to 35.9 s; P = .339).

Targeted training combined with video- and sensor-based feedback led to a successful implementation of a terrain-specific micropacing strategy in XC skiing, which reduced the time spent in downhill and flat terrain for intervention compared with a control group. However, no change in overall performance was observed between the 2 groups of XC skiers.