FIT FOR LIFE:How much physical activity is enough to gain benefit? asks Giles Warrington
WE KNOW that regular participation in physical activity is important for physical and mental wellbeing and for our long-term health promotion. So how much exercise do you need to do to get these benefits?
The American College of Sports Medicine and the American Heart Association have recently updated the recommended guidelines on physical activity and public health. The primary recommendations are that, to maintain and promote health, adults aged between 18-65 years of age should engage in "moderate" aerobic (endurance) activity for a minimum of 30 minutes for five days weekly.
Alternatively, you can participate in "vigorous" intensity activity for a minimum of 20 minutes on three days each week.
So what does this mean in practical terms? For the purpose of these recommended guidelines for physical activity participation, "moderate" exercise is equivalent to a brisk walk designed to elevate the heart rate and increase the rate of breathing.
Effectively, at this intensity, you should be breaking into a sweat, breathing relatively hard, but able to maintain a conversation with an exercising partner. In contrast, "vigorous" exercise, such as jogging, leads to rapid breathing and a marked increase in heart rate.
These activity patterns are over and above routine daily living activities, such as casual walking and shopping.
However, the type of moderate and/or vigorous intensity activities undertaken should be incorporated into your daily routine and include activities such as brisk walking or sweeping up leaves.
To achieve these minimal targets, a wide variety of activities could be included which take into account individual interests, work, family and social commitments as well as other lifestyle and environmental issues.
For those individuals who have difficulty committing to 30 minutes of continuous activity each day, more recent evidence has shown that moderate-intensity exercise in short bouts of about 10 minutes that are accumulated towards the 30-minute daily activity target can be as effective as a longer single bout in enhancing health and wellbeing.
Also, a combination of moderate and vigorous aerobic activity can be performed to achieve your weekly physical activity targets.
In addition to aerobic activity, you will benefit from performing activities designed to maintain and improve muscular strength and endurance on a minimum of two days per week. Such activities would include exercises using your own body resistance, weight training, weight-bearing activity and stair-climbing.
It should also be remembered that individuals participating in aerobic and strength activities above the minimum recommended levels outlined provides for additional health benefits as well as enhanced physical fitness.
Put simply, the more exercise you do, the greater the health benefits and the lower the risk. Furthermore, physical activity of longer duration or higher intensity has been associated with further risk reduction.
Nevertheless, for those starting off, you should aim for the lower end of this target and gradually increase your physical activity levels as you establish a training routine and become fitter.
Now that you have the facts, it's a case of taking the first steps to a new healthier lifestyle. In next week's article, we will be looking at practical tips for getting started.
• Dr Giles Warringtonis a sport and exercise physiologist and lecturer in the School of Health and Human Performance at DCU