What is high-intensity interval training (HIIT)?

Nick Beer explains what high-intensity interval training is, the benefits, and how to incorporate it into your triathlon training


The concept of high-intensity interval training (HIIT) is to increase your heart rate to its maximum, and follow it with a short recovery that causes your heart rate to drop. The intensity is then increased once more, so you reach your max heart rate again. This is repeated numerous times for 10-30mins, depending on the ability of the individual.

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Interval training: why and how

 HIIT is used in all types of sports and fitness regimes with the goal to improve VO2 max, increase your anaerobic threshold and burn fat, so it’s ideal for triathlon.

The flexibility and simplicity of HIIT offers itself as a perfect addition to training that can be included to add variation, increase power and fitness, and sharpen you up for racing. On the surface it appears that HIIT will be suited to athletes racing super-sprint and sprint distances due to the shortness and the intensity of the efforts. However, even for longer-distance triathlons (Olympic and above) adding a short intense workout to your plan once every 3/4 weeks (depending how your programme is structured) can shock the body from its usual training routine and potentially add fitness benefits.

A sport-specific, high-intensity interval training circuit has many benefits for the athlete. To the right is an example of a HIIT bike-to-run brick training session (please adjust according to your fitness level) that can be used by triathletes at any time of the year to get themselves race ready, but is ideal for the summer months as you lead into your ‘A’ race.

HIIT brick session (bike to run)   

  • Ideally using a turbo and either a treadmill or a field/road to run on/have easy access to.
  • Have your run shoes next to the turbo in readiness to transition into running off the bike.
  • On the bike carry out 8 x [60sec max sprints, 30sec easy spin].
  • No break once finished; straight off, run shoes on and straight into your running.
  • On the run, carry out 8 x [45secs fast, 15secs easy jog].
  • Take an extra 5mins full rest after the run and repeat the whole set 2/3 times.
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