Summer Interval Frequency

By Selina Campbell

A question we get asked a lot here at TCR is ‘how often should I be doing intervals through the summer?’ And as always, the answer is… it depends!

It depends on your age, your experience, if you race, and if so, how close to your race you are.

Generally, as we age, we absolutely need to keep interval training in our schedule BUT quality over quantity. That is, our body will get more benefit from fewer quality workouts, than more attempted interval sessions that fall short of our potential because we aren’t adequately rested to perform our best.

The idea of intervals (and when I use the term ‘interval’ I am referring to any intensity around Z4-5+ i.e., threshold and above) is to stimulate muscle fibre recruitment and physiological adaptations to the workload in those muscle fibres. So, the harder we work, the stronger the stimulus and therefore adaptation. The problem comes when we try to cram too much into too short a time frame. Our body isn’t unable to perform at the level we want (because its tired), so the power we hit is short of the target and we get a sub-par session and therefore sub-par training effect.

However, going in strong and refreshed allows maximal effort, maximal stimulus and therefore maximum benefit.

I had a learning of this myself recently. I just came back from 5 days in Palm Springs – I rode my bike every day, but it was all super light Z1 volume, along with a couple of easy recovery swims and light runs. I then hopped on my bike to do 10 min threshold intervals for the first time in a week (rather than my 2x/week attempt) and was VERY pleasantly surprised… the power was up around 10w and the RPE (Rate of Perceived Exertion) level was way down. My body was rested and recovered, even after 5 back-to-back days of 2 workouts/day because they were all super low intensity, meaning my interval session was better quality and therefore will have had a stronger training effect than my usual 2x/week efforts.

Below is a table with a suggestion of interval workout frequency through the summer, as we all get more outdoor volume in. Keep these latter rides Z1-2, then weave in 1 intensity as per below and then on rides when your buddies want to hammer (or you have a race) reap the benefits of training smart 