How much HIIT should I do a week?

It’s time-efficient, effective and highly fashionable, but is HIIT training really the silver bullet some make it out to be?

A new study, published in Cell Metabolism, Best wireless headphones.

In the study, volunteers completed 14 HIIT sessions on a cycle ergometer for four weeks, with the training load increasing during the first three weeks.

Up to week three, which had the highest training volume, the participants’ cycling performance increased. But, at the end of week three, their power output no longer improved and there was a marked decrease in intrinsic mitochondrial respiration (IMR) – that is, the capacity of mitochondria to produce energy – as well as a reduction in glucose tolerance and insulin secretion.

Although participants were completing eight-minute “all-out” intervals for five days straight – which is probably much more than you might do down at your local gym – it’s worth limiting your HIIT sessions to just two or three a week to protect your metabolic health.

The best interval sessions according to science

A new meta-analysis What is the average walking speed Sports Medicine, has discovered the magic formula when it comes to boosting your speed over a set distance. And it consists of two simple sessions – one for speed endurance, one for top-end speed.