| 13 October 2009
A refreshing cooling breeze and some late afternoon cloud cover over Mooloolaba beach provided an ideal climate and location for exercise. Judging by the numbers of people on the beach in their exercise gear, I wasn’t alone in thinking it was the perfect time for exercise.
As I began my run I soon realized that over 95% of people who thought they were exercising on the beach were not actually exercising. Technically they were moving (they were walking) but to me exercising is when you engage in physical activity with enough intensity and for long enough so that it improves your physical fitness.
When your time is limited as is generally the case with most working families today, you want to ensure that your time spent on exercising is going to give you the best reward for effort. Unfortunately, new research is showing that by following the current exercise recommendations you will miss out on many of the health benefits that you can get from exercise.
The study published in the October 2008 edition of The Official Journal of the American College of Sports Medicine1 by Dr. Paul Williams is highlighting the accumulating evidence that important health benefits accrue at greater exercise doses and greater exercise intensities than currently recommended.
Guidelines from the American College of Sports Medicine, the American Heart Association and the Australian Government many other health promotion organizations and governments around the world emphasize the health benefits of briskly walking 3 kilometres per day for five days per week. (That equates to 25-30 minutes of walking per day). So for most people that equates to a total of 15 kilometres per week at a 6 km/hour pace or slower...
In a survey of 25 552 male runners and 29 148 female runners they found a very clear reduced need for medications in people that exercised at a higher intensity. For example men who ran faster than 13.7km /hour pace required 72% less blood pressure medication, 78% less cholesterol medication and reduced the odds for requiring diabetic medication by 67% when compared to the men who ran at slower than 9.6 km/hour pace.
For women, the result was equally emphatic. Women who ran at 12km/hour pace had reduced odds 61% of requiring blood pressure medication, 64% less need for cholesterol medication and an 87% less likelihood of requiring diabetic medication.
Now before you jump on a treadmill and run at 12 or 13.7 km/hour, you need to realize that running at that kind of speed is initially beyond the novice or beginner. It is a cracking pace that will leave most people gasping for air.
So all of you people who think walking is good exercise need to think again. Most people who walk do so at about 6km/hour. At this pace walking is just a different form of rest and relaxation. Walking only becomes exercise if you are walking at an intensity that causes you to puff. But unless you are walking up steep hills at a rapid pace or you are grossly out of shape it is hard for most of us to walk at a pace that makes you puff.
So how hard should you exercise at?
I have always advocated the importance of exercising your body at different gears of intensity for maximum health benefit. Just like a car your engine works more efficiently when you use all your gears. And like driving a car, your life rarely goes at the same speed or in the same direction. When you have trained your body’s engine to go at comfortably at different intensities you will be able to easily and safely adapt to the different intensities in life.
Previous research highlights how exercising at different intensities improves different aspects of your health. Swain and Franklin2 found that vigorous exercise produces greater reductions in diastolic blood pressure (in a blood pressure of 120/80, your diastolic is 80) and greater improvements in sugar control than moderate exercise. Vigorous and moderate exercise was found to have an equivalent effect on systolic blood pressure (the higher blood pressure number) and body fat.
So what does this all mean for you?
- For beginners to exercise, what type of exercise you do or how intense you should do it is not the most important objective initially. The important thing to focus on at the start is to get into the habit of exercising. Just do whatever you enjoy but do it at intensity where you are just beginning to puff.
- After a period of between 6 weeks and 4 months of regular exercising (and you have got into the habit of exercising) to reap the full health benefits from exercising you must stop exercising in moderation exercise at begin to exercise at varying intensities. Be sure to include more intense forms of exercise so you can reap the extra health benefits. Mix it up… the variety will add more life for you to spice.
References
- Williams, P.T. The Relationship of Running Intensity to Hypertension, Hypercholesterolemia, and Diabetes, Journal of American Coll. of Sports Med, pp 1740-1748, Oct 2008.
- Swain, D.P., Franklin, B.A. Comparison of cardioprotective benefits of vigorous versus moderate intensity aerobic exercise, Amer. Journal of Cardiology, 2006; 97; 141-7.
