Dr David Collison PhD

The Collison Newsletter April 2013




Regular exercise can help protect you from a wide variety of diseases, as well as improve your mood and help you to manage stress better.

Over the last six years, at least nine of my newsletters have encouraged regular exercise for well-documented health benefits:

March 2008Prevention of Cancer. Food, Nutrition, Physical Activity and the Prevention of Cancer
June 2008Health Benefits of Weight Reduction and Exercise
September 2008Metabolic Syndrome
May 2009Depression - Non-pharmaceutical Treatments that Work
April 2010Benign Prostatic Hyperplasia - Lifestyle and Herbal Treatments
November 2010The Health Benefits of Exercise
January 2011Preventing Cancer - Global Report Recommendations
October 2011Healthy Living and the Prevention of Chronic Disease
May 2012Depression Natural Treatments

Yes, we have heard it before, "Exercise in good for you because....". We need to exercise, but how often we procrastinate, make excuses (too busy, no time, inconvenient etc) or just do not get around to doing it. As a result, the overweight/obesity epidemic is with us, and deaths from cancer and cardiovascular disease remain high.

The following figures are from the Australian Bureau of Statistics (

For the first time since 1995, the 2007-08 National Health Survey (NHS) has measured the height, weight, hip and waist circumference of respondents aged 5 years or more. Results from this survey reveal that, in 2007-08:

  • 61.4% of the Australian population were either overweight or obese
  • 42.1% of adult males and 30.9% of adult females were classified as overweight (BMI between 25.0 and 30.0). [BMI is Body Mass Index, ie kg/height in metres squared]
  • 25.6% of males and 24.0% of females were classified as obese (BMI >30.0).

In 2010, the leading underlying cause of death for all Australians was ischaemic heart disease, causing 21,708 deaths, 15.1% of all deaths registered in 2010 (a reduction of 5.3% since 2001). Cerebrovascular disease has remained the second leading underlying cause of death in 2010.

The proportion of deaths due to circulatory disease (ischaemic heart disease, cerebrovascular disease and other vascular diseases) was 31.7% in 2010 (a decrease of 6.7% from 2001).

The proportion of deaths due to neoplasms (all types of cancer) was 30.2% in 2010 (an increase of 1.0% from 2001).

So why another newsletter about exercise? To repeat the message that regular exercise can help protect against and prevent certain diseases and promote better health.

Exercise Helps Prevent Disease

Sometimes even the thought of exercise seems hard. But the truth of the matter is that you will be a healthier person for it, and not just in terms of cardiovascular fitness. Exercise helps prevent disease. As an active person, you are less likely to develop a number of diseases.

Regular physical activity that is performed on most days of the week reduces the risk of developing or dying from some of the leading causes of illness and death in Australia. notes that regular physical activity, ie exercise:

  • Reduces the risk of dying prematurely
  • Reduces the risk of dying prematurely from heart disease
  • Reduces the risk of developing diabetes
  • Reduces the risk of developing high blood pressure
  • Helps reduce blood pressure in people who already have high blood pressure
  • Reduces the risk of developing colon cancer
  • Reduces the feelings of depression and anxiety
  • Helps control weight
  • Helps build and maintain healthy bones, muscles, and joints
  • Helps older adults become stronger and better able to move about without falling
  • Promotes psychological well-being.

Specific Health Benefits of Exercise

Heart disease and stroke

Daily physical activity can help prevent heart disease and stroke by strengthening your heart muscle, lowering your blood pressure, favourably influencing blood cholesterol levels, improving blood flow, and increasing your heart's working capacity.

High Blood Pressure

Regular exercise can reduce blood pressure in those with high blood pressure levels.

Non Insulin-Dependent Diabetes

By reducing body fatness, physical activity can help to prevent and control this type of diabetes. The Finnish Diabetes Prevention Study showed that moderate physical activity, combined with weight loss and balanced diet, can confer 50-60% reduction in the risk of developing diabetes.

Obesity and Weight Reduction

Regular exercise helps to reduce body fat by building or preserving muscle mass and improving the body's ability to use calories/joules. When physical activity is combined with proper nutrition, it can help control weight and prevent obesity, a major risk factor in many diseases.

Exercise is typically recommended for weight reduction. Exercise by itself is not a fast-track to weight loss, but it does offer important benefits beyond cancelling out calories/joules. It slightly increases the rate at which you burn up calories/joules even when you are not working out.

3,500 calories are stored in one pound of body fat. (1 calorie = 4.1858 joules, 1 pound = 0.453kg).

Walking or jogging uses roughly 100 calories per mile (1 mile = 1.61 kilometre). So you would lose a pound for every 35 miles you walk (provided you keep food and other activities constant).

If you walk briskly (at a pace of 4 miles per hour) for 30 minutes on five out of seven days, you will have walked 10 miles a week. This means that it would take three and a half weeks to lose one pound.

If you alter your diet and reduce 250 calories a day, you would lose a pound in two weeks.

By eating 250 fewer calories and walking for 30 minutes every day, it would take just over a week to lose one pound. Reducing calorie intake even more and exercising more would further speed the weight loss.


Regular weight-bearing exercise promotes bone formation and may help prevent the bone loss associated with ageing.

Psychological Effects

Exercise can improve your mood and the way you feel about yourself. It reduces depression and helps you to manage anxiety better.


With regular exercise you will be better able to get off to sleep and stay asleep.

Fighting Disease with Exercise

Aerobic exercise is the centrepiece of any fitness program. Nearly all the research regarding the disease-fighting benefits of exercise revolves around cardiovascular activity, which includes walking, jogging, swimming, and cycling.

Aerobic exercise is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process. Aerobic literally means "living in air" and refers to the use of oxygen to adequately meet the energy demands during exercise via aerobic metabolism.

Aerobic exercise (also called cardiovascular exercise, aerobics or simply cardio) is constant, moderate-intensity exercise that uses oxygen at a rate in which the cardiorespiratory system can replenish oxygen in the working muscles.

The target heart rate during aerobic exercise, derived from the Karvonen formula, is:

(220 minus age) multiplied by 0.75.

For example, the target heart rate for a 52-year-old would be 126 [(220 52) x 0.75 = 126].

This goal heart rate (pulse rate) is the target: the intensity of the exercise should be progressively increased until the rate is achieved, and then maintained during the exercising period.

Experts recommend working out at moderate intensity when you perform aerobic exercise -- brisk walking that quickens your breathing being one example. This level of activity or exercise is safe for almost everyone (excluding those with known heart disease) and provides the desired heath benefits. Additional health benefits will flow-on from increasing intensity until the target heart rate is reached.

The type of exercise chosen is up to you. Walking is still "the best exercise". In addition to aerobic exercise, weight training may also be beneficial. However, for health benefits, aerobic exercise is the way to go.

The Secret to Better Health is EXERCISE.


*Copyright 2013: The Huntly Centre.

Disclaimer: All material in the website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.