HOW TO GET FIT - A Scientific Approach

For many decades, scientists have been conducting research into fitness and how best to achieve it. Largely, the findings make their way to peer reviewed journals and not as far as the general public other than in dribs and drabs. What's interesting is that scientists have actually broadly reached a consensus. This article looks at the do's and don'ts of fitness and busts a few myths along the way.

One of the first studies of fitness was published in 1953. They looked at bus conductors and bus drivers. The results published in the Lancet (vol 265, p1053) showed that the conductors suffered half as many heart attacks as drivers. The link between the sedentary life of the drivers vs the constant climbing of stairs and health was made. These days, the advice is 150 minutes of moderate exercise a week. Studies suggest that only one third of adults achieve this in spite of fitness and exercise being implicated in the prevention of strokes, cancer, diabetes, liver and kidney disease, osteoporosis, brain disease, dementia and depression.


When planning exercise for the week, studies show that segments of exercise as small as 10 minutes are just as effective as any, it all adds up towards your 150 minutes per week. This is good news for those of us with busy schedules who find it hard to set aside a number of chunks of time a week. In fact Steven Blair, Professor in the Departments of Exercise Science, University of South Carolina suggests that 'ten minutes is as far as the data takes us but I think five-minute bouts would be fine too, but we just don't have the data yet'.


The measure of the rate of energy expended while doing work or exercise is known as metabolic equivalents or METS. This gives you an indication of how hard you are working during exercise or your metabolic rate during any given activity. A comprehensive list of activities and their MET value can be viewed at . As a guide, 100 steps per min is equivalent to 3 METS whereas playing football would be around 7.


When you look at an ultrasound scan of an athletes heart compared to an unfit person, the left chamber which is responsible for pumping the blood, is much larger and more muscular. This is because when you get fit a number of changes take place. The body becomes better at delivering oxygen to the muscle cells, muscle fibres grow and the mitochondria increase in size and numbers releasing more energy from glucose.


Well a study published in 2008 which followed the health of over 8000 men for two decades found that found that the mortality rates for those whose muscle strength was in the bottom third for their age was 30% higher than rest taking aerobic fitness into account. The conclusion was that both aeobic fitness and muscle strength contributed independently to overall health. As a result the American College of Sports Medecine added strength training to its recommendations on exercise. They suggested specifically ten reps of ten strengthening exercises twice a week.


If you build up your fitness, you can reduce your risk of having a heart attack by as much as 50 to 80%. That said, exercising vigorously raises your risk of having a heart attack two times if you are fit and 100 fold if you are unfit. So if you plan to run for that bus then you are much more likely to survive if you have kept yourself in shape.