# Energy Structure of Repeated On-Ice Efforts and Its Dependence on the Aerobic Capacity of a Hockey Player

## TL;DR

This study examines how ice hockey players use energy during repeated high-intensity efforts on the ice.

## Contribution

It quantifies the relative roles of aerobic and anaerobic energy systems in hockey performance.

## Key findings

- Aerobic energy contributes most (63.1%) to repeated high-intensity on-ice efforts.
- Phosphagen metabolism contributes 29.8%, and glycolytic energy contributes 7.4%.
- Performance is more related to metabolic tolerance than VO2max.

## Abstract

Background: Ice hockey is characterized by repeated short-duration, high-intensity efforts interspersed with brief recovery periods, requiring a complex interaction of aerobic and anaerobic energy systems. The aim of this study was to determine the energetic structure of repeated high-intensity on-ice sprint exercise in ice hockey players by quantifying the relative contributions of the oxidative, glycolytic and ATP–PCr energy systems. Methods: 14 male semi-professional ice hockey players performed the 30–15IIT followed by the Repeated High-Intensity Effort (RHIE) on-ice. Oxygen uptake was measured breath-by-breath, blood lactate concentration and energy system contributions were estimated using a three-component PCr–La–O2 model. Results: The RHIE on-ice was characterized by a dominant aerobic contribution (63.1 ± 2.6%), followed by phosphagen metabolism (29.8 ± 2.9%), with a relatively small glycolytic contribution (7.4 ± 1.5%). Conclusions: No significant relationships were observed between maximal oxygen uptake (VO2max) and the RHIE performance parameters, energy system contributions or lactate responses, except for a moderate relationship between absolute VO2max and absolute aerobic work. In contrast, parameters determined at the anaerobic threshold showed more consistent relationships with absolute metabolic work. These findings indicate that repeated high-intensity on-ice performance in ice hockey is largely independent of VO2max and is more closely related to individual energetic profiles and metabolic tolerance.