Some people seem to work out and work out but don’t get any fitter. And that’s true for both aerobic exercise and weight training. I suggested earlier that such people might make a rational choice not to exercise.
After all, they’re doing the work but not seeing the usual benefits. In that post, Rational couch potatoes unite I looked at a number of studies of non-responders, all of which noted a wide variation in response to exercise. There isn’t a one size fits all approach to “couch to 5 km.” It might take some people weeks and others months. Ditto for speed.
And I talked about the variability and the need for personalized exercise programs in Personalized exercise, recovery, and the unfit.
A new study though casts doubt on the existence of non-responders and suggests that they are only non-responders at low doses of exercise. The cure for non-responders might not be a more gentle approach to exercise. The best cure might be working harder, more intensely, and for longer periods of time. They’re not non-responders. Instead, they just need a higher dose.
That’s either good news or bad news depending!
See Non-responders just need to try harder in the Globe and Mail. It describes a study conducted by Dr. Robert Ross and his colleagues in the School of Kinesiology and Health Studies at Queen’s University. They compared the results of three different 24-week exercise programs on 121 sedentary, obese adults.
The researchers measured aerobic fitness every four weeks, and saw the number of non-responders in all three groups decline as the study progressed. In the low-amount, low-intensity group, however, the non-response level plateaued after eight weeks, with more than one-third of the subjects still failing to see any improvements after 24 weeks.
That suggests the minimum exercise level prescribed by health guidelines isn’t sufficient for everyone: “It’s just not enough to move the needle on a number of people,” Ross says. “I mean, [a non-response rate of] 30 per cent is not a trivial number.”
Doubling the amount of low-intensity exercise reduced the non-response rate to 17.6 per cent, but the most impressive results were recorded in the high-intensity group, in which the number of non-responders was reduced to zero by the end of 24 weeks.
So maybe non-responders are people for whom the right amount of exercise is a lot and the right intensity level is high.