New study suggest aerobic exercise is useless for those with “unfitness” genes

A controversial new study published in the Journal of Applied Physiology is raising eyebrows amongst the scientific community and triggering a typical sensationalized reaction from the media. The study, lead by James Timmons, evaluated the fitness improvements in around 600 volunteers who were cycling at a moderate intensity for 30 minutes a day.

The researchers found that some participants improved their fitness levels by 10% whereas the fitness levels of about 20% of them barely changed. The researcher then examined this 20% and found a group of genes that affect oxygen uptake that they believe could be responsible for the lack of results from exercise. They suggest that these “unfitness genes” could be stopping 20% of the population from burning fat off during aerobic exercise.

As you could imagine, the media have gone to town on this with saying: “Exercise is a waste of time”, “Jogging is useless,” “If you can’t get results from exercise , it’s not your fault, blame your parents,” “Exercise is waste in time for the 1 in 5 who have inherited “unfitness” genes.” To many people who have tried all sorts of fitness programs to no avail is genetics the answer or is it just a convenient excuse?

But first I want to address the media inaccuracies…

…The media went about claiming that all exercise is useless for those with these “unfitness” genes. Various reports go on to say that this study proves that activities like swimming, running and going to the gym won’t be of benefit for this 20%. In actuality, the subjects cycled at a moderate intensity for 30 minutes a day. They never tested the effects of other exercises like running, swimming, going to the gym or tested the effectiveness of exercising at different intensities in the study. So, in essence this study shows you that moderate aerobic exercise does not improve the fitness of everyone.

One thing giant flaw in the study is because the researchers were focussing on possible genetic causes they choose to ignore quite simple explanations for the results in addition to less expensive and more common sense solutions. The simplest explanation for the results is to understand that exercising at the same moderate intensity will not benefit everyone because people have different levels of fitness at different intensities.

This is because different people go about life at different paces/intensities you develop fitness at operating at that certain intensity. The key is to change the intensity of your exercise. I call it exercising right for your engine type (see Day 10 in  the book From Burnout to Balance in Four Weeks).

Just like it is important for your cars engine that all five gears operate well to develop your overall fitness you also need to be fit at different intensities. Improving your fitness through exercise requires balance. To boost your fitness you need to exercise at intensities that you don’t normally operate at (or in the gears that you don’t normally use).

For example, if you live life flat out (or in overdrive), you will get little benefit from high intensity exercise. You will need to exercise your lower gears. If you live life at a moderate to slow pace you are already fit in these lower gears. To boost your fitness you will need to exercise the higher gears at a higher intensity. In fact, the lead researcher of this study, James Timmons has already published research showing the fitness benefits of small bursts of high intensity exercise.

I don’t believe that our genes are such a big cause of so many of our ills and here are two reasons why…

1) If you look at the the sudden surge in obesity levels over the last decade yet our genes have barely changed.

2) The Pima Indians are known to be genetically predisposed to obesity. Why then are the Pima Indians in the Southern USA obese yet the genetically same group of Pima Indians living in Northern Mexico are slim? The only difference is their lifestyle.

You could say that having one of these so-called “obesity” or “unfitness” genes is a bit like being handed a gun. They can only do damage if you pull the trigger…and poor lifestyle habits like not exercising will pull the trigger.