How much exercise is good for my health?

Recent research demonstrated that to achieve the potential health benefits associated with regular exercise may be achieved by doing it more frequently, for a longer duration but at a lower intensity than was recommended previously.

Traditionally, the exercise intensity recommended and “prescribed” by your doctor to improve your general health or very specifically as part of the management of a chronic disease, were mainly determined by a sliding scale of maximum heartrate for each gender and age group. Typically, 220 minus your age. So, if you are 50 years of age you must achieve a heartrate of 220-50 = 170, which usually requires a fairly high exercise intensity.

The good news is that recent research demonstrated that to achieve the potential health benefits associated with regular exercise may be achieved by doing it more frequently, for a longer duration but at a lower intensity than was recommended previously. The health benefits from regular exercise apply for a wide range of chronic diseases and conditions including high blood pressure, diabetes, osteoporosis, depression, general anxiety, and obesity as well as general conditioning in the person without any underlying diseases. These health benefits are achieved by firstly making a conscious decision that exercise becomes a daily routine and then going from doing no or little exercise even to a minimal level of regular exercise.  In time, as exercise intensities, frequency and duration of the exercise increase, even additional benefits are derived.

But how do you determine the “dosage” of exercise that is right for your genetics, your physical make-up and underlying health condition? This exercise “dosage” refers to the frequency, the intensity, and the duration of every exercise session as well as the type of exercise. It will obviously also take into consideration your current exercise programme.

The new emerging research shows that Cardiopulmonary Exercise Testing (CPET) is a reliable method to determine the “dosage” of the exercise as well as to monitor the impact of the “exercise prescription” over time. Historically, CPET was used mainly in the identification and performance management of high-performance sportsmen and -women. The fact is that CPET has now become a very important technology to personalised medicine, which is also a new approach that emphasises the customisation of healthcare, with all decisions and practices being tailored to individual patients, in prevention of illness, maintenance of health and the management of disease.

The CPET-laboratory looks like a gym with treadmills and exercise bicycles and computers. The person taking the test will be required to perform mild exercise to start off with followed by gradual increase in intensity on the bicycle or treadmill whilst breathing through a mask. During the exercise blood pressure will be monitored and the heart performance traced by an electrocardiogram (ECG). Inputs from the breathed air, blood pressure and ECG are collected in linked computers with programmed formulas to produce a report on your exercise, including the oxygen used and carbon dioxide produced by the cells in the body for each breath taken. The reports so generated assist in drafting of an exercise programme that is tailor -made for you and which will allow the maximal benefit for you personally.

Let’s look at the science behind the CPET. This information produced during the exercise is used by the clinical team to assess your heart, lungs and metabolic function. Your exercise tolerance is determined by how effectively oxygen and carbon dioxide is exchanged in the lungs, the pumping performance of the heart and the ability to transport oxygen rich blood to the cells of the body and take carbon dioxide back to the lungs but also how your muscles are using the oxygen during exercise.

The information so derived is in addition to standardised tests and imaging studies currently performed and CPET is now applied for the assessment of risk before and after operations, the identification of heart and lung disease not diagnosed by other tests, and even for people with so-called long-COVID-19. The outcomes from these studies currently performed in South Africa are living up the huge potential of personalised exercise programmes for the healthy and those with illness alike.

Although not mainline in the clinical setting yet, CPET may play a significant role in the future as diagnostic and guidance for exercise in management of chronic disease and rehabilitation.

Dr. Martin de Villiers is the Medical Director at Medwell SA.

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