DNA testing for health and fitness

I don’t know about you, but the thing I like when I hear people talking about DNA testing is that it is objective. You can look at a set of results and they will tell you in the most unbiased way possible what is going on. For example, if somebody says that they can’t handle their drink and become drunk easily, that appears to be a completely subjective point of view. But if you say that having had a DNA test, I now know that my body metabolises alcohol at a much slower rate then you instantly appear more credible.

Most of us think about DNA testing in the context of preempting disease. So you submit a cheek swab, wait for a few weeks and then you are told about all your genetic attributes that make you more likely to suffer from, or pass on, certain genetic diseases. None of that is really that new. But we are interested in how this translates to our health and fitness. Well personal trainers who want to really tailor a workout for their client will go to some length to find out about how you live your day-to-day life. Personal trainers who want to go that bit further will want to know about your family history and DNA testing will tell them that without even having to ask.

This throws open the whole nature vs nurture debate and that isn’t something that can be covered in one blog post. I’ll just assure you that neither side is being forgotten. Of course there are obvious environmental factors that can undo any genetic advantage that you might have. A DNA test will tell you about your VO2 max for example, which I’m sure you will have come across before. So if you score highly on that then you know that you have a good lung capacity and that you can regain fitness levels relatively quickly. Does that mean that you don’t have to put in as much work to get the same results? Well of course it doesn’t.

What it does mean however is that compared to someone with a lower score, you should be able to recover fitness more quickly and therefore be able to achieve more aerobically in the same period of time. The idea that because you have a genetic advantage means that you can take it easier is ridiculous. What it means is that you should be achieving more just by putting in the same amount of work so you have no excuse to fall behind.

This directly relates to our diet as well. Firstly, a DNA test will tell you how likely you are to suffer from conditions like coeliac disease and could explain why you might feel sick when you eat bread for example. It also tells us about how your body works with different nutrients. So for example, a test could indicate that your body relays carbohydrates into fats relatively quickly. The job then is to work out what to do with the information. Hopefully it should seem quite obvious that in this scenario a low-carb diet is probably the best course of action.

I think the reason why people are reluctant to talk about genetic factors that relate to fitness is because it leaves the option for making excuses. So somebody might find out after a DNA test that they are more prone to muscular injury and as a result don’t work as hard in the gym for example. Clearly that isn’t the best way to use this information. But to go on pretending that every individual is the same and that a workout regime that works for one will work for all isn’t the best idea either. Knowing more about our genes just allows us to make more informed decisions about how we train. People who want to put the work in will do so whatever the results and the people who want to make excuses will always find a way.