Fit vs Fat – Some Thoughts

In a recent editorial in the British Journal of Sports Medicine1, Steven Blair, a professor in Exercise science and Epidemiology states there is now ‘over whelming evidence that regular physical activity important and wide ranging health benefits’. He goes on to state that physical inactivity is one of the most important health issues of this century. Not diabetes, not obesity, but lack of fitness. This is brought out by recent British newspaper articles2 quoting research that children these days on average take 90 seconds longer to run a mile than their parents 40 years ago.

How bad is this as a problem compared to what we hear daily in the press about obesity? In a large study in the USA1 (40000 men and13000 women) low cardio respiratory fitness was responsible for 16-18% of all deaths, whereas obesity was only 2-3% and high cholesterol 2-4%. That is not to down play these other factors, but more to emphasise a factor that has ‘been missing’ from our health message – or has it?

As far back as 1999 a study3 of men was undertaken to assess the influence of BMI on cardiovascular disease and total mortality (deaths from all causes). What they found may surprise you. If the risk of dying for a fit male with a normal BMI was ‘1’, the risk of dying for an overweight but fit male was only 1.1. However the risk for a normal BMI, but unfit male was 2.2 – that is they were twice as likely to die of any cause as the fit over weight male.

Where does this leave us with regard to health aims? Many people have had bad experiences with attempts to lose weight and goals are hard to achieve and enthusiasm hard to maintain when those scales are not dropping fast enough. If these people focus more on their fitness, which is easy to track, they can relate any gains directly to improved health outcomes, and over time there will probably be a positive side effect of losing weight as well.


  1. Br J Sports Med January 2009 Vol 43 No 1
  3. JAMA 1999, 28 1547-1553

Hamish Ashton – Sports Physiotherapist