Dear Coach: Why Are HIIT Workouts Important for Older Athletes?

Thanks to experts like Dr. Stacy Sims, the importance of HIIT (High-Intensity Interval Training) workouts for mature athletes has gained a lot of attention recently. So you may be asking yourself: Am I a “mature” athlete? Why are HIIT workouts so important? And how do I incorporate them into my triathlon training? Let’s tackle these questions one by one.

Am I a “mature” athlete?

For the purposes of this discussion, we are going to categorize “mature” athletes as women over the age of 45 and men over the age of 60. This is based on hormone levels and has nothing at all to do with whether you laugh at fart jokes. You can still laugh.

RELATED: Read our series on ‘The Mature Athlete’

Why are HIIT workouts so important?

As we age, our hormone levels change, which produces associated changes in the way our bodies and brains work. Most relevant to this conversation is the change in how our bodies build and maintain muscle as well as how those muscles perform.

So how do muscles change as we age? Firstly, the speed and strength of muscle contractions lessen. Then to compound the problem, muscle tissue breaks down quicker and is also harder to build. All of this translates to: mature athletes tend to have less muscle mass and get less out of the muscle they do have. Why does this matter? Well, to put it simply, muscle = power = speed. Less muscle means less speed. And we all want speed.

This is where HIIT workouts come into play: HIIT workouts are one of the best ways to stimulate muscle production. Plyometrics and strength training with heavy weights are two additional high-value workouts that help build muscle.

RELATED: Ask a Trainer: What’s the Best Strength Workout for Triathletes Over 50?

How do I incorporate them into triathlon training?

If you have a coach, follow a training plan, or read my previous Dear Coach about when to incorporate interval training, you are likely already doing interval sessions on the bike and run each week.

Older athletes, requiring more consistent muscle-building stimulation, will benefit from one or two additional interval sessions each week. However, the typical interval session has a higher training stress impact and therefore produces greater fatigue than a typical endurance session, so if you swap out endurance workouts for typical interval workouts, you’re going to find yourself overly fatigued, or even over-trained, in short order.

The key to trading endurance workouts for supplemental HIIT workouts within your week is to structure the HIIT workouts so they have a similar training stress impact to endurance workouts. What these workouts look like in practice is three to four sets of four to six 20- to 30-second Zone 5b (well-above-threshold) intervals with equivalent rest between intervals and about five minutes rest between sets. By following this model, you can incorporate one or two extra interval sessions in your training week and stimulate muscle production without accumulating excessive fatigue.