How Physical Activity Prevents Lifestyle Disease

by Paul Rogers on December 20, 2010

Compared to how humans lived prior to civilization, and even how people lived up until the present century – and some still do – we in the developed nations move very much less. It may be obvious, it may be overstated and it may seem trivial in the scheme of healthy living, but it is not.

In Dan Buettner’s best-selling book, Blue Zones, in which he investigated communities of long-lived people in different parts of the world, he noted the lifelong physical activity of these people, many of whom were centenarians — physical work during the day, and then often recreational walking or hiking as well. Working in a vegetable patch all day might expend an extra 1200 kcalories (5000 kjoules) over 6 hours compared to sitting in an office. This is about equivalent to an additional 3 hours of fast walking you would need to do if you sit at a computer, relatively inactive all day. That is a very significant amount of extra physical activity.

I’m making this point because many of us have lost perspective on exercise and physical activity in a modern world. We don’t need to work in a field all day, but to be in tune with a level of activity that kept us lean and mean for thousands of years, we do need to know what the score is. Getting physically active IS absolutely crucial to a long and strong life. You can probably live long, and even well, but if you want to live long and strong, you must stay active until you drop. That’s the truth of it, even allowing for someone with superman genes. You use it or you lose it.

Every bit helps. It’s not dangerous if you start slowly and combine it with healthy eating. Yet not everyone likes exercising their butt off just for fun; you need to find a pattern – there’s that word again – that fits with your lifestyle and your predilection. Even so, there are extra benefits to be had with regular physical activity of defined quality and quantity.

Here are a few of the most important health benefits of regular exercise:

— Increases heart and lung fitness and stamina
— Protects against heart disease, stroke and diabetes
— Helps create a favourable energy balance and normalises weight
— Builds muscle, strength and flexibility
— Enhances glucose metabolism and improves insulin function
— Helps to maintain or enhance bone density
— Improves immune function and reduces inflammation
— Protects against some cancers
— Improves mood and helps ward off depressive states

Cardiorespiratory fitness (heart-lung fitness)

Cardiorespiratory fitness is measured by the amount of oxygen that the body can consume for any given activity over time. In simple terms: how well the heart and lungs and muscles can handle physical activity challenges. This is often given as the VO2 or VO2max in millilitres/oxygen/kilogram/bodyweight/minute. Numerous studies have shown that this measure of fitness is associated with lower risks of heart disease, diabetes and overall risk of dying. Cardiorespiratory fitness may also be measured by heart rate recovery after exercise, or heart rate reserve, the difference between resting heart rate and maximum heart rate.

In one study in the New England Journal of Medicine, participants with the best heart rate recovery after exercise had four times less chance of dying in the 10 years of follow-up. Using this measure of fitness, you should be able to recover at least 30 beats per minute from your maximum heart rate after one minute of rest. If your maximum heart rate was 170 BPM, then after one minute, in a person of superior level of fitness, the heart rate would be less than 140 BPM. In the very fit, it will be lower still.

Energy balance and resting energy expenditure

Energy balance refers to the equilibrium between food intake and energy expenditure so that weight is maintained at a more or less steady state. Exercise helps to maintain the balance in weight maintenance or create a deficit, which acts in favour of weight reduction and normalisation of ideal weight.

The basal or resting metabolic rate (RMR) is the amount of energy expended at rest in order to maintain critical body system functions. Regular exercise can increase the RMR. The higher the RMR, the easier it is to lose or maintain weight. Muscle tissue uses more energy than fat tissue, and although fat cannot be converted to muscle, fat can be shed and muscle can be increased, which will in turn increase metabolic rate, although this advantage is slight. Enhanced heart and lung function and capacity, called cardiorespiratory fitness, also increases basal metabolic rate.

Importance of exercise during weight loss

Exercising during a weight loss program is not only important for addressing energy balance, but also for maintaining muscle and bone, which can be lost with sudden weight loss, especially with very low-calorie diets.

Preventing diabetes

Glucose is stored in muscle and liver in a form called glycogen. Exercise helps remove glucose from the blood by using glucose for fuel, and by enhancing the efficiency by which glucose is stored and retrieved in muscle, liver and fat cells. Muscle and blood fats (triglycerides) are also used up and this helps fat metabolism. Improving the way insulin works – called insulin sensitivity — is part of the positive effect of exercise.

Cardiovascular and cardiorespiratory disease

Physical activity improves heart and lung fitness, reduces inflammation, increases high-density lipoprotein cholesterol (the good cholesterol), lowers resting heart rate, improves heart rate reserve (the difference between resting heart rate and maximum heart rate), and improves heart rate recovery after exertion. All of these measures lower the risk of heart disease and stroke and peripheral artery disease.

Cancer

While the factors in physical activity that protect us from cancer are not well understood, improved immune function, obesity prevention, amelioration of fat and glucose toxicity, and the reduction of inflammation and modulation of insulin and glucose in the body are likely candidates.

— Physical activity lowers the risk of colorectal and breast cancer
— Obesity and overfatness increase the risk of cancers of the breast (post menopause), endometrium (the lining of the uterus), colon, gallbladder, kidney, pancreas and esophagus

Mood and depression

Regular exercise is now recognised as being so effective at improving mild to moderate depressive states, that mental health professionals are now starting to prescribe it to patients.

In summary, physical activity should be at the heart of anti-ageing, longevity and wellness goals. Peak nutrition, or at least something approaching it, is the other key to healthy ageing. Get both right and you have a good chance of cancelling out the negative aspects of the genes you have been dealt.

Previous post:

Next post: