23 extra hours of training did not change performance.

You finish the interval session and the hard work makes sense.

Five four-minute efforts. Three minutes easy between them. You know what that part of the week is there to do.

It is the extra four hours of easier riding that can be harder to explain. They take more time, they make the training week look complete, and we tend to assume they must add something. But what if the intervals are already doing the work?

A new six-week study tested exactly that in 19 moderately trained cyclists and triathletes. Seventeen were men. Both groups completed three interval sessions each week. Every session included five four-minute efforts at 85% of peak work rate, with three minutes of loadless spinning between efforts.

One group stopped there. The other added 240 minutes of continuous riding each week at 80 to 90% of LT1. Across the six weeks, that added up to roughly 23 extra hours of training.

Both groups improved their cycling time-trial performance by an average of 8.5 ± 1.2%. The researchers found no statistically detected difference between the groups for time-trial performance, peak work rate, LT1 or LT2.

The group doing the extra riding trained for around 23 hours longer and did not record a bigger improvement on the tests the researchers used.

At first glance, that sounds like a reason to remove the easy hours.

It is not.

Worth being straight about what this study can and cannot tell us. It lasted six weeks, included only 19 riders and was overwhelmingly male. The exploratory analysis suggested the researchers would have needed more than 100 riders in each group to detect the between-group difference they observed. They had 19 riders in total.

The study also measured a short block through a time trial, peak work rate and lactate thresholds. It did not measure durability after three or four hours, preparation for a long event, or what happens across a full season.

And it did not test tempo after the interval set. The extra riding was completed separately across the week. That is a different session and a different question.

The useful reading is much narrower.

Across a short interval block, the intervals were the obvious lever for the performance test. Adding another four hours each week did not automatically create a bigger six-week result.

That does not make the easier riding pointless. It means you need to be clear about the job you expect it to do.

Use the hard sessions to create the hard stimulus. Keep the easier riding easy enough to support the week and build work you can repeat. Do not add hours just because a fuller training week looks more serious, and do not remove them because one short study failed to find an extra time-trial gain.

What you do with this depends on which rider you are.

If you're time-capped: the instinct is to take this as permission to replace the easy riding with more intervals. Don't. Protect the hard sessions that matter, then use the time you have left for genuinely easy volume that supports them.

If you're over 50: the instinct is to copy three hard days because they drove the six-week gain. Be careful. Three interval sessions a week is a serious recovery demand. The easier work only helps if it leaves you able to absorb the hard work and repeat it.

If you're chasing a result, or it's a new event for you: the instinct is to train for the test that moved in the study. Start with the demands of your event instead. If it is long, durability still matters, and this study did not measure it.

The lesson is not that easy hours do not work. It is that every hour needs a job.

Source. Moran-MacDonald A, Wilson S, Wu Z, Haines G, Beaupre L, Aube J, Andrews C, Jonsson N, Gurd BJ. The effectiveness of polarized versus high-intensity training in moderately trained cyclists: a randomized parallel-design study. European Journal of Applied Physiology. 2026. https://doi.org/10.1007/s00421-026-06380-w

On my mindMomentum

In cycling, momentum is close to the whole game.

You let go of the brakes so you can take the corner properly. You carry speed through the dip so the climb starts with something already moving.

Training has the same shape.

It takes work to get the flywheel turning. Then the sessions that used to feel out of reach start looking normal.

The temptation is to interrupt that momentum every time one session feels flat or one number does not move.

I think that is where a lot of good training gets lost.

Momentum is not doing more for the sake of it. It is keeping the useful work moving.

— Damian