New study shows that high-intensity interval training is an effective training tool that enhances endurance performance.

Researchers at McMaster University in Ontario, Canada recently compared the physiological and performance effects of both interval and traditional endurance based training by using sixteen men placed into one of two cycling groups. The sprint training group performed four to six all out maximal 30 second sprints separated by four minutes of recovery. The traditional endurance training group performed continuous exercise for 90 – 120 minutes at an intensity of 65% of maximal aerobic capacity.

The duration of training was only two weeks and performance was assessed by pre and post training time trials that were designed to measure the time to complete a designated amount of work. Muscle samples were also taken prior to and after the two weeks of training.

Results showed no differences in performance (the time to complete the trials). Whereas the sprint training group showed an improvement of 10.1%, the traditional endurance training group only improved by 7.5%. Additionally, both groups exhibited the same adaptations in muscle oxidative capacity, buffering capacity, and glycogen utilization.

The key aspect of this research was the difference in the time commitment to the two training protocols. The sprint training required only 2.5 hours a week while the traditional endurance training program required 10.5 hours a week. However, the sprint training program yielded results that were equal to or better than the endurance program.

Based upon these findings, the authors concluded that high-intensity training may be a very time efficient way to induce physiological adaptations similar to those seen with traditional long term endurance training.

Source: Journal of Applied Physiology, 575:901-911, 2006.