Archive | November, 2013

Preventing and managing disease: Is exercise prescription the answer?

29 Nov

Written by: A. Erin Connelly

Physical activity for good health isn’t a new idea, but there is a recent push to encourage primary care physicians to prescribe exercise plans for patients. It is well known that “being active” is beneficial for health, but recent reports indicate that 85% of Canadians do not meet the exercise guidelines of 150 minutes per week (Colley et al 2011). Similar to medication, increasing physical activity levels works best when patients know what type of exercise, how much, and how often. A number of research studies have shown that specific written exercise programs for sedentary adults result in higher activity levels than just general advice as a prescription provides direction, accountability and the feeling of tangibility that comes with a prescription (Duncan et al 2005; Smidt et al 2005).

Exercise is Medicine (EIM) is one organization that is promoting this idea. The American College of Sports Medicine and the American Medical Association launched EIM in 2007 and an EIM chapter has been recently established by graduate students in the Department of Human Health and Nutritional Sciences at the University of Guelph. The Guelph chapter will be promoting physical activity as a means of prevention and treatment of disease within the Guelph community, and providing information and resources to assist health care providers in prescribing exercise as medicine.

In the same way researchers test the efficacy of a drug or supplement, exercise prescription has been tested in controlled clinical trials. In one study, cardiovascular related outcomes were compared between a group of sedentary adults prescribed a walking program of specific duration, intensity, and frequency compared to a group of sedentary adults given written materials on exercise for health.  All groups exercised for 30 min per session, and the group prescribed exercise for 4 days per week at high intensity, and 7 days per week at moderate intensity, experienced the greatest improvements in cardiorespiratory fitness and positive effects on cholesterol levels (Duncan et al 2005). The group that was not given a specific walking program reported much lower levels of activity and smaller changes in fitness and cholesterol levels.  Another large study used data from 305 controlled trials with a total of 339,274 participants and concluded that exercise intervention studies are the same as or better than drugs in the secondary prevention of coronary heart disease, rehabilitation after stroke, treatment of heart failure, and prevention of diabetes (Naci et al 2013).

Specifically, for people with type 2 diabetes, poor fitness level is one of the strongest predictors of all-cause mortality (Church et al 2004), which is part of the reason the Canadian Diabetes Association has created an exercise prescription pad for physicians to use in prescribing exercise to diabetes patients (see figure below).   This type of prescription pad is easy for physicians to use and for patients to understand.   Although the advice is targeted to patients diagnosed with diabetes, adults needing to reduce their risk of type 2 diabetes would benefit as well.

Exercise is a non-specific term. It includes activities that vary in type, frequency, intensity, and environment. It is well known that being active and exercising is a great idea for health and happiness, but many adults find excuses not to exercise.  Exercise prescription is a promising way to get people to actually change their activity levels and improve health.  Check out the Guelph EIM facebook page for more information:


1) Colley RC, Garriguet D, Janssen I, Craig CL, Clarke J and Tremblay MS.  (2011) Physical activity of Canadian adults: Accelerometer results from the 2007 to 2009 Canadian Health Measures Survey. Component of Statistics Canada Catalogue no. 82-003-X Health Reports Statistics Canada. Vol. 22, no. 1

2) Duncan GE, Anton SD, Sydeman SJ, Newton RL, Corsica JA, Durning PE, Ketterson TU, Martin AD, Limacher MC, and Perri MG. (2005) Prescribing Exercise at Varied Levels of Intensity and Frequency. A Randomized Trial.  Arch Intern Med. 165(20):2362-2369.

3) Smidt N, de Vet HC, Bouter LM, and Dekke J. (2005) Effectiveness of exercise therapy: A best-evidence summary of systematic reviews. Australian Journal of Physiotherapy. Vol. 51: 71-85

4) Church TS, Cheng YJ, Earnest CP, Barlow CE, Gibbons LW, Priest EL, and Blair SN. (2004). Exercise Capacity and Body Composition as Predictors of Mortality Among Men With Diabetes. Diabetes Care. vol. 27 no. 1 83-88

5) Naci H and Ioannidis JP. (2013) Comparative effectiveness of exercise and drug interventions on mortality outcomes: metapepidemiological study. BMJ. 347:5577