One Workout

Aerobic Intervals

Are you hoping to perform well in your next 5k or 10k race? There are many ways to increase aerobic capacity, but I have found that high-volume, controlled, sub-maximal aerobic intervals have greatly increased my endurance in the last few months, leading to new PBs in both the 10,000m and the 5,000m. I believe they can benefit anyone looking to PB at any distance from the 1,500m to the half-marathon.

The goal is to run a high volume of fast running by splitting that distance i nto short-to-medium intervals with very little rest. For a beginner, it might mean 3 km to 6 km of volume; for an intermediate or advanced runner, aim for 8–12 km. You should aim for a rhythm somewhere between your half-marathon and 10k race pace. Intervals should be between 400 m and 3 km, with no more than one minute’s rest between intervals – enough that the heart rate remains high, while resetting the body mechanically with each new interval. The workout represents an honest and constant aerobic effort.

Try to run as smoothly as possible throughout the session by focusing on your mechanics, and try to maintain that form as long as possible. If you start to fatigue and feel yourself tightening up, use that minute’s rest to reset your body. Don’t run each interval full-out. If, after one or two repetitions, you are already struggling and tightening up, slow down until you are more comfortable. At the end of these sessions, you don’t want to be completely spent, and you should be able to say that you could have completed more intervals.

The following are examples from my last buildup, spanning several months. Go slower or use shorter distances in the early sessions. As your fitness increases, you can use interval length, rest, speed and overall volume to make the session more challenging, but you should always feel in control of every workout.

Charles Philibert-Thiboutot is an Asics athlete, 2016 Rio Olympian and three-time Canadian national champion in the 1,500m.