Purpose: We investigated whether 4 weeks of intensified training consisting of speed endurance training (SET) enhanced high-intensity exercise performance in youth national-team ice hockey players.

Methods: Utilizing a randomized crossover design, we subjected 17 players to 4 weeks of SET, comprising 6 to 10 × 20 seconds at maximal effort (>95% maximum ice skating speed) with 120-second recovery performed 3 times weekly, or maintenance of regular training (control period). Before and after each period, players completed ice-hockey-specific tests on ice, including a Yo-Yo Intermittent Recovery Level 1 test, a 30-m sprint test, and an agility test. On a separate day, players were assessed for body composition with dual-energy X-ray absorptiometry and performed countermovement jump, maximal voluntary isometric knee extensor contraction, a 15-second maximal sprint test, and a submaximal and incremental test on a bike ergometer in which pulmonary oxygen consumption was determined.

Results: Yo-Yo Intermittent Recovery Level 1 test performance increased (P < .001) by 14% (95% CI, 201-496 m) during the SET period. Maximal pulmonary oxygen consumption (P < .05) and time to exhaustion (P < .05) were 4.8% and 6.5% higher, respectively, after the SET period than before. Fat-free mass increased (P < .01) during the SET period by 1.7 kg (95% CI, 1.0-2.5), whereas fat mass remained unchanged. These effects were superior to the control period.

Conclusions: These findings underpin the effectiveness of SET for improving on-ice high-intensity performance and highlight that elite ice hockey players can benefit from implementing SET.