This article has been published in Medicine Today, a peer-reviewed journal for doctors. Read the full article here
Exercise is Medicine
Physical inactivity is a major modifiable cause of disease burden world wide, yet 60% of Australians don’t meet the recommended guidelines for physical activity. It’s a commonly known fact that obesity is a risk factor for death and disease, however what most people don’t realise is that being unfit can actually lead to a greater risk of death than being fat.
Fitness versus Fatness:
A meta-analysis by Barry et al published in 2014 looked at the risk of death in 92,986 subjects. Participants were divided into 3 weight groups based on BMI: normal weight (BMI 18-25), overweight (BMI 25 – 30) and obese (BMI > 30) and those groups were then split into fit and unfit based on cardiorespiratory fitness during VO2 testing. The fit group was the top 80% of fitness scores in each weight category and the unfit group were the bottom 20%. The groups were followed over time and the risk of death in each group was compared to the normal weight fit group. The overweight and obese fit groups had a small, insignificantly increased risk of death compared to the normal weight fit group (1.13 and 1.21 more times likely to die respectively) but it was all three unfit groups that had alarmingly increased risk. The unfit normal weight group were 2.42 times more likely to die than their fit counterparts, with a 2.14 times increased risk in the fit overweight group and 2.46 times more risk in the fit obese group. This study highlights the importance of physical activity and shows that it’s better to be fit and fat than normal weight and unfit.
Benefits of regular exercise:
Regular participation in physical activity increases cardiorespiratory fitness and is known to reduce the risk of health problems such as cardiovascular disease and stroke, type 2 diabetes, cancer, depression, osteoporosis, and osteoarthritis. Exercising regularly helps reduce plaque build up in coronary artery disease by favourable effects on the blood vessels, blood pressure and lipid profiles. Physical activity can enhance skeletal muscle response to insulin, increasing insulin sensitivity for hours to days after exercise and reversing or preventing the effects of type 2 diabetes. Exercise during treatment for cancer can help manage side effects, reduce negative effects of treatment such as muscle loss and fatigue, delay progression of disease, lower recurrence rate and improve survival. Physical activity helps lift spirits and relieve stress by releasing mood elevating hormones. It reduces joint pain and helps protects joints by building muscle strength to lighten the load put on them. Weight bearing and impact exercises can prevent bone loss associated with ageing and improve bone mineral density in those with low bone density. It also reduces risks of falls and fractures.
The World Health Organization recommends that adults undertake 150 minutes of moderate physical activity such as walking per week, which equates to half an hour per day for 5 days a week, where each day can be split into 3 x 10 minute bouts of activity. Alternatively, the same benefits are derived from 75 minutes per week of vigorous activity (eg jogging or other aerobic exercise). Additional health benefits are available when this amount is increased to 300 minutes of moderate activity (60 minutes each day for 5 days) or 150 minutes of vigorous activity. It is also recommended to participate in strength exercises for all the major muscle groups twice per week and older adults at risk for falls benefit from including balance exercises too.
Even if you are not able to reach the minimum exercise guidelines right away, it is important to do as much exercise as you can and try to increase it gradually. You can start low intensity exercise such as walking straight away, however for exercise more vigorous than a brisk walk or exceeding demands of everyday living, previously sedentary and older people may benefit from being assessed for conditions that might be associated with higher cardiovascular risks and should speak to their doctor first. Our sports doctors are more than happy to consult on exercise prescription for health and you can see one of the registrars without needing a referral from your GP.
- Barry et al Fitness vs. Fatness on All-Cause Mortality: A Meta-Analysis Progress in cardiovascular diseases 2014; 56: 382–390
- American College of Sports Medicine Roundtable on exercise Guidlelines for Cancer Survivors. Med Sci Sports Exerc. 2010; 42(7): 1409-1426
- Friedenreich et al, Clin Cancer Res. 2016; 22:4766-4775
- Colberg SR, Sigal RJ and Fernhall B et al. Exercise and Type 2 Diabetes. The American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care 33:e147– e167, 2010
- Warburton DER, Nicol CW and Bredin SSD. Health benefits of physical activity: the evidence. CMAJ 2006; 174(6): 801-809
- Australian Institute of Health and Welfare 2012. Risk factors contributing to chronic disease. Cat No. PHE 157. Canberra: AIHW.
- Global recommendations on physical activity for health. Switzerland, World Health Organization, 2010.