PrintAre You Working Out Hard Enough?

Haven’t been noticing any results from your exercise routine? New research suggests that you might just not be working out hard or often enough.

While it’s true that some people don’t respond as well to exercise as compared to others, a recent study confirms that there’s really no such thing as an exercise “nonresponder.” In fact, similar to prescribing a drug, it’s more likely that, due to individual genetic variability, some people just need a higher dose of exercise to notice improvements.

Exercise researchers David Montero and Carsten Lundby thought that it sounded a little suspect that “one in five adults” didn’t respond to exercise. Out of their curiosity came the hypothesis and a study that evaluated if the problem of “nonresponders” depended on the length of time exercising or the type of exercise studied.

To remove confounding variables, Montero and Lundby set up a two-phase design with multiple groups. Specifically, they divided 78 healthy adults into five groups that performed either one, two, three, four, or five one-hour long exercise sessions per week at 65 percent power output as part of a six-week training program.

After this period, they identified those who did not improve their cardiorespiratory fitness as “nonresponders.” Later they had those same subjects go back onto the second six-week program that included two additional exercise sessions per week.

Prior to and after each phase, they measured maximal oxygen consumption (Vo2 Max) as well as potential oxygen capacity and muscle determinants of work output. With these, they determined which parameters could explain variations in trainability.

The study found that the second six-week exercise period with two additional exercise sessions per week, succeeded in eliminating “nonresponse” in all subjects.

The subjects did increase their oxygen capacity and power output, but more importantly they showed significant improvement with regards to changes in hemoglobin – a protein found in red blood cells that binds oxygen. Using these measures, the researchers determined that the subjects improved their use of oxygen and could exercise at a greater intensity.

From the research, Montero and Lundby concluded that the prevalence of cardiorespiratory fitness nonresponse gradually declined and was “universally abolished” in healthy individuals as their exercise frequency increased.

These findings highlight the need to re-evaluate current concepts about human untrainability and even exercise prescription.

Because of the potential benefits of daily exercise – including decreased risk of cardiovascular disease and other chronic diseases – it may also mean that those who aren’t getting results might need to increase their exercise frequency for results.


Montero D and Lundby C. Refuting the myth of non-response to exercise training: ‘non-responders’ do respond to higher dose of training. J Physiol. 2017 Jan 30.