How Much Exercise is Enough?

There is much debate in the world of science as to the ideal amount of exercise necessary to maintain health benefits and ward off chronic diseases like hypertension and diabetes.

Every few years the trend-setters in exercise prescription, the American College of Sports Medicine and the Canadian Society for Exercise Physiology, revise their physical activity recommendations to better suit Western lifestyles while achieving health benefits.

The pendulum has swung from three exercise sessions per week at 70 percent of heart rate max, to 30 minutes of physical activity per day in a minimum of 10 minute intervals.  This then conceded to 150 minutes of total moderate physical activity per week or 75 minutes of total vigorous physical activity per week.

It is no wonder that the average person is confused as to what they should do.

A recent study published in the Journal of the American Medical Association (JAMA) Internal Medicine reveals even weekend warriors can experience the health benefits of exercise.  Weekend warriors are those individuals who generally do not have the opportunity to exercise regularly, but will find time once per week for an intensive session, often in a recreational sport setting.

Healthy man Running on Treadmill

The study’s authors used previous survey results and tracked all-cause mortality rates and found that even those who exercised one time per week achieved significant health benefits.  The participants were achieving the guideline of 150 minutes of moderate or 75 minutes of vigorous activity, but doing so in one exercise interval.

In the past, the weekend warrior approach to exercise has been discouraged as it tends to be associated with higher rates of injury as a result of overzealous, deconditioned participants not gradually increasing their exercise load over time.  Now, some may argue that the health benefits may offset some of the injury risk.

How hard you exercise plays a role in how long you need to exercise.  In fact, recent research at McMaster University shows that four minutes of total activity performed as repeated 30-second sprints on a bicycle are just as good as 40 to 60 minutes of submaximal cycling for health and physiological benefits.

Cycling Class at the Gym

Although scientists may undergo significant hand-wringing over the dilemma of appropriate exercise volume for health, what this study demonstrates is that a little exercise is better than no exercise.  Standing is better than sitting, walking is better than standing, running is better than walking.

As with other medicines, exercise has a dose response.  What that means is the more you get, the greater effect it will have on your physiology up to a certain point.  After that, you start to be at risk for overuse injuries.

Trevor Cottrell MH headshotFor those who are unsure where to start and what to do, one thing is clear: to achieve health benefits, movement is good, more is better, and the harder you work the less you have to do.

This blog post was written by Trevor Cottrell, PhD, CSCS, Director of Human Performance, Memorial Hermann IRONMAN Sports Medicine Institute.


  1. Great information here. I think starting slow and building up slow is the best approach. If you go all out you are probably going to either get injured or burned out, neither achieving your long term goals. Thanks for sharing!

Leave a Reply

Your email address will not be published.

Tashika Varma