Runners rely on interval training as one of the most effective ways to build speed and endurance. The thing about high-intensity interval training is that you can only do it for so long before you hit a wall or have to stop due to the build-up of lactic acid or fatigue in your muscles. When working out at high intensity, the active interval has to go hand and hand with the rest interval to help you get the most out of your performance.
How long should your rest be between intervals?
There are a few ways you can structure your interval workouts: You can keep the interval short with very high intensity and the rest periods long or keep the rest and interval phases roughly equal or do longer intervals with shorter rest to improve your aerobic capacity. What is the best way to structure your training? Or does it not matter?
A study published in the Journal of Strength and Conditioning looked at this issue. The researchers asked six people to run on a treadmill as fast as they could for four minutes with various rest periods between. The study found that the rest depends on your training goals and what you’re looking to improve.
Reducing the rest interval from two minutes to one minute made it difficult for the six runners to maintain the same intensity during the high-intensity intervals. Another interesting observation was that the rest interval of four minutes did not improve performance any more than the previous two-minute recovery period.
Regardless of this study, there is no single right or wrong way to structure interval training, but it does depend on what you are trying to achieve. If your goal is to improve your aerobic capacity, longer active intervals of two to five minutes and roughly equal recovery periods seem to work best. But if you want to improve your top-end speed or anaerobic levels – 30 seconds to two minutes of rest is prescribed for those who want to run at a higher intensity for longer or faster.