The body was made to move and, despite the turmoil that has resulted from the global coronavirus pandemic, one thing it has reinforced is just how big a priority our health is - not just physical, but mental too. While we’ve long been told that we need to be getting in our daily exercise and counting those steps, as far as high-intensity exercise goes, it turns out there is such a thing as too much exercise. Interval training (or HIIT) has garnered quite the cult-like following over the years, with a number of luxe gyms opening up catering specifically to this fitness trend. While these 45-to-an-hour classes certainly get us out of a fitness slump and burning those calories, we could be overdoing it.
Researchers in Sweden recently published a report in Cell Metabolism in which they surveyed 11 healthy men and women who were tasked with completing varying levels of HIIT training over a four-week timeframe. In week one, they performed just two HIIT sessions at four minute intervals and during week two they completed three sessions with some intervals as long as eight minutes.
Then, post-workout muscle tests were conducted and revealed that the participants were improving their physical condition as their cells showed better glucose regulation and more efficient energy-producing mitochondria. But when a third week was added, detailing five days of HIIT a week, the numbers took a sudden decline.
Researchers found that there was a reduction in mitochondrial function and a disturbance in glucose tolerance and insulin secretion causing big ‘ups and downs’ in glucose across the day. In the fourth recovery week, exercise was halved, and participants once again began to improve, but were still sitting at 25 per cent less energy than they had in week two.
What we can take away from such studies is that HIIT workouts are best completed in a balanced way, like two to three times a week, so as to avoid what researchers call “excessive training load,” whereby overall health declines. A similar result was found in a New York Times story, which covered a study comparing HIIT to more regular medium-intensity workouts. Published in Medicine and Science in Sports and Exercise, they found that normal half-hour mid-intensity workouts on a regular basis had better results on blood pressure, body fat and overall metabolism than interval training.
So, if the thought of skipping a workout over the Easter break has you stressing, don’t panic. Perhaps it’s just the break you need to see your body once again reach optimum health.