Body Mass Index

Right, yesterday I touched on the topic of Body Mass Index and today you might have to excuse my rant, but this a topic that continues to frustrate me.

For those of you that don't know what this means, it's a simple calculation that the health services use to compare height to weight. All they do is take your weight, your height and then do a short sum, or use a table, to decide which range you fall into. The ranges are "Underweight" (below 18.5), "Normal" (18.5 to 24.9), "Overweight" (25- 29.9) and "Obese" (30+) and are used to suggest your potential health risks.

Now, these calculations don't take into account how much muscle the person has, and therefore how much of their weight is body fat. As far as I know, I haven't ever heard of increased cardiovascular health risks due to increased muscle mass. It's the fat that's the killer, right?

Most of us know now that the most effective way to burn fat and to keep it off is to increase your lean muscle mass, thus increasing your resting metabolic rate (simply put, you burn more calories, even at rest, if you have more muscle), combined with the right nutrition programme. It's inevitable that you are going to increase weight by increasing muscle mass, and the problem is that different people burn the fat at different rates. So, initially when someone starts doing weight training they might put on muscle before they lose much fat and even put on a little weight. If they persist, though, the increased muscle mass will have the desired effect of burning more fat, and often their weight will drop again (unless they're going for serious muscle building).

Now, to be fair to the health services they do state on their literature that the ranges don't take into account muscle mass. But what gets me is how many people are still using their weight as a guide to their progress.

I'll give you another example of the obsurdity of this weight/height comparison. Both Alex and I are keen Rugby fans (Alex, in fact, was a professional Rugby player earler in his career). Now, it's a sad time to be an English rugby fan at the moment, but watching those guys play 80 minutes at the intensity they manage is incredible. Their fitness is unreal. However, if you took their weight to height ratios, and used the BMI scale, I reckon 80% at least would be classed as "Overweight", whilst many of the forwards would be classed as "Obese". Admittedly, although the shape of Rugby players has become more athletic over the last few decades, some of them still carry a fair bit of fat round the middle. But even the fattest of those guys has fitness levels that would embarass most of us.

So, stop using your weight as a guide to your progress. Find someone who can analyse your body fat percentage (either a Bio-electrical impedence measurement, or Caliper measurements). Take pictures of yourself (the camera doesn't lie), or simply see how your clothes feel or dress sizes change. Test all areas of your fitness regularly and look at what you're eating. But please, don't use your weight as the only guide to how well you're doing in your fitness training.

Are you fit enough for "The Hardcore Workout"?

Andrew & Alex