In last week’s article, we spoke about a trainer being honest with his/her/their client about health benefits and health risks of being active or inactive. We used a simple measure of health — the Body Mass Index (BMI) — to bring across the point, but is it really the best way to define health? Today, we’ll look at a few common ones such as the BMI, the body fat % and the VO2Max (a basic measure of the body’s ability to distribute and utilise oxygen).
BMI — BMI stands for Body Mass Index. It is literally a ratio of a person’s weight to height. It is literally calculated by dividing weight (in kg) by the square of the height (in m). It is used to roughly estimate a person’s health status. However, it is highly inaccurate in some regards. A BMI of 18.5-24.9 is considered healthy, while below is underweight, above is overweight and, in the extreme, above 30 is obese. However, this does not take into consideration a person’s body fat % or general fitness levels. It cannot possibly be used to diagnose any chronic health issues, but if your BMI is out of the ‘safe’ range, it generally warrants further investigation. The major drawback to this is that one may have a ‘good’ BMI but still be unhealthy. Someone may have a high body fat %, but still be in the ‘good’ range for BMI. This simply means that he/she/they have very little muscle mass and may actually be at risk for hypertension and other chronic illnesses.
Body Fat % — This is a measure of adipose tissue (fat) in the body. It can be measured using calipers (skinfold measurement), electricity (bioelectric impedance), or even a big tank of water (hydrostatic weighing). All of the different methods give different levels of accuracy, but they are all better as estimating a person’s health status than BMI. There is a direct correlation between body fat % and chronic diseases such as hypertension and diabetes. This does not always hold true for BMI as athletes tend to be quite fit and healthy (not all, but most) and their BMI doesn’t always fall within the range of ‘good’. It is also the simplest way for a doctor, personal trainer or nutritionist/dietician to estimate health and set out a plan to assist an individual.
VO2Max — This literally means Maximum Volume of Oxygen and is a measure of how much oxygen a person uses during intense exercise. This is, perhaps, one of the better measures of cardiorespiratory fitness and, by extension, health. It utilises the theory that there is a direct correlation between it and energy generation. This can further be extrapolated to determine the efficiency of one’s metabolism, thereby determining a risk for chronic disease. It is primarily used to determine an athlete’s fitness level, but has applications in non-athletes as well. One can predict the VO2Max of a healthy non-athlete. However, if it is too low, it can be safe to say that the individual may not be healthy with a high level of accuracy. However, you are not able to determine what the health issue is using VO2Max alone. Also, this test is not readily available as it requires specialised equipment and technicians/doctors with the knowledge of how to read and interpret the information.
So, there you have it: three ways in which health is measured. They are listed from most accessible to least accessible, but this order also corresponds to least accurate up to most accurate. If you have any concerns about your health, please employ at least the first two of these methods and seek further advice from a health and/or fitness professional.