I believe it was Descartes who many years ago claimed that mathematics was the true foundation of all sciences.
From the information-processing algorithms that make your smart phone tick, to the mathematical constants gloriously revealed by the growth of petals, plants and even the bones of the human body, mathematics is everywhere.
It enhances our lives in a host of often under-appreciated ways, from predictions of weather patterns to how much cash you might have left over at the end of the month to invest in a loan or savings plan. It’s no wonder one of the internet’s biggest celebrity scientists Professor Kaku famously proclaimed, “God must be a mathematician!”
When it comes to measuring and predicting stuff, the exercise and fitness world gives us a few little nifty formulae of our own. So even for those hands more accustomed to the rough knurling of barbells than delicate calculator controls, consider that the two might actually be better off hand in hand. From the very moment we decide to pursue a healthier and more active lifestyle, the measurement quickly begins.
Goals work best when they are specific, and you can’t get more specific than cold, hard numbers. From girth measurements to body fat testing, getting to grips with the formulae of fitness can ensure your journey gets off to the right start. Body Mass Index (BMI) is a simple numerical test we often start with.
To find your BMI, multiply your height by itself, and then divide your weight by whatever answer you got. If your final answer is anywhere between 18 and 25, then you are considered to be within a healthy weight range. Under or over these values is unhealthy, while scoring over 30 is considered obese.
The formulae become a little more complex when it comes to body fat percentage testing, but that is simply because body fat testing is a more advanced and generally more useful test all round. If we take the “Eurofit” four-site test then the combined reading in millimeters of the skinfold thickness at four set sights around the body are fed into the Durnin/Womersley formula.
This formula factors in your age and provides a result to be fed into a second formula, known as the Siri body fat formula, to give you your final reading as a body fat percentage of overall body weight.
This information allows you to take into account your muscle to fat ratio without being misled by the overall weight readings displayed by your bathroom scales, which naturally cannot distinguish between muscle and fat weight.
It’s actually hard to think of fitness and anthropometric tests that don’t involve numbers, so what happens to the mathematics of muscle once all the calipers, inch tapes and weighing scales have been cleared away?
You’ll often find that, even with your training programme in hand, the numerical figures remain ever-present to guide you through your sessions towards the physical figure you seek. Intensity in resistance training is often expressed as a percentage of one-rep-max.
The one-rep-max is the most amount of weight you can lift in a given exercise only once. There is of course a problem with finding out what it is, because actually attempting to lift the most amount of weight you can possible overcome in exercises that are new to you can be dangerous to say the least. Well, luckily we have a few clever exercise scientists to wave their magic mathematical wands.
The Brzycki formula allows us to, based on the amount of weight you can lift say nine times, calculate how much weight you are most likely to be able to lift once, thus predicting your one-rep-max a lot more safely than performing vein-popping maximal attempts on the squat machine.
For cardiovascular training like running, cycling, striding and stepping we have another mathematical guideline. Just like our muscles can only lift a finite amount of weight, there is a maximum amount of intensity our heart can deal with too: the maximum heart rate, expressed in beats per minute.
Once again, instead of jumping on the treadmill and attempting to run at your absolute maximum capacity for the purpose of establishing what your maximum heart rate is, you can use a simple formula. First you’ll need to calculate 70 per cent of your age, and subtract your answer from the number 208. For a forty year old individual for instance, this would work out at 180 beats per minute.
Knowing your maximum heart rate, you can now calculate how hard you need to work during your run or cycle. You can perform regular instensity checks with more fun mathematics by finding your pulse and counting off the beats over the course of 15 seconds. Multiply that number by four, and you have your heart rate in beats per minute.
To trigger beneficial physiological responses from your sessions, an intensity of 70 per cent of maximum heart rate is considered the benchmark for a moderately intense workout. Over 80 per cent can be considered very tough fitness training. These standards correspond to 126 and 144 beats per minute respectively in the example of our forty year old individual. So if you’re looking for an effective workout, you are going to need to work hard enough to remain within those values for the entire duration of your planned session.
So if you’re looking to streamline your training efforts and get more scientific about achieving your goals, then it’s to start working those figures in every sense of the phrase, and bank on the fitness universe’s own theory of everything; physical activity and healthy living plus a positive mindset and will to achieve is equal to better health and the body of your dreams.
matthew.muscat.inglott@mcast.edu.mt