Life

How much exercise is really enough?

PATRICIA CHISHOLM June 3 1996
Life

How much exercise is really enough?

PATRICIA CHISHOLM June 3 1996

How much exercise is really enough?

Life

There they sat, month after month, unwieldy hunks of plastic and steel, gathering dust and taking up space. Of course, Montrealers Antoinette De Iure and Fiore Egiziano had the best of intentions when they forked out $1,600 for a home gym and Nordic Track last year. But like many Canadians who vow to shape up, they soon shipped out their new equipment—running a classified ad to sell the barely used hardware. And who can blame them? With their jobs—

Egiziano, 43, is an optometrist, and De lure, 38, is a part-time occupational therapist—there is barely enough time to spend with their three small children.

And then there was the tedium of sticking to a routine.

“The machines were in the basement and it was not very stimulating,” De lure says. The couple have not given up altogether: they still work out two or three times a week on a stationary bike and treadmill in front of the main-floor TV. “I exercise because I have to,” De lure admits. “It’s something you have to do, like brushing your teeth.”

Actually, North Americans are far more faithful about tooth brushing than they are about exercising. Recent surveys in Canada and the United States show that a stunning 80 to 90 per cent of North Americans fail to hit the pavement, the pool or the gym as often as they should. And how often is that? In July, the U.S. surgeon general is expected to release its long-awaited Report on

Physical Activity and Health.

Experts in Canada and the United States say the influential agency will offer concrete advice on how much—and what types of—exercise are most beneficial, an issue that has recently been muddied by a raft of contradictory studies. And it is expected to come down hard on people with sedentary lifestyles, warning that inactivity greatly increases the risk of heart disease, hypertension, certain cancers, diabetes and osteoporosis. “This will be a historic event, similar to the 1964 surgeon general’s report that started the anti-smoking cam-

paign,” claims John Wildman, president of Toronto-area health club The Fitness Institute. “The surgeon general will probably direct doctors to prescribe exercise as a preventive measure—it will be seen as an imperative for good health, not a choice.” While Canada has no specific guidelines on exercise, a working group that includes Health Canada, academic researchers and

nonprofit agencies is developing proposals to establish such recommendations following the release of the surgeon general’s report Meanwhile, any couch potato who requires more convincing need only gaze up at the mountain of research linking mortality rates and inactivity. Last year, a prestigious panel of U.S. experts published a report in The Journal of the American Medical Association, pointing out that lack of exercise causes a quarter of a million deaths in the United States every year. The massive Nurses’ Health Study, a long-term investiga-

tion of risk factors affecting 73,000 American women, reported in 1995 that those who are most active reduce their risk of heart attack and stroke by more than 40 per cent, compared with those who are sedentary.

While none of this is news to health professionals, experts cannot seem to agree on how much exercise is enough. Ten years ago, the official line was tough: exercise for 20 minutes, three times a week or more, hard enough to work up a sweat and get the heart working at 60 to 90 per cent of its maximum capacity. In other words: no pain, no gain. But the vast majority of people just said, No way. (The percentage of heavy exercisers has remained steady for the past 15 years.) Changing tacks, re-

A raft of contradictory studies leaves people even more confused over how to get fit

searchers in the early 1990s concluded that virtually any exercise is better than none at all. Some studies even showed that 30 minutes of moderate activity three or four times a week carried health benefits similar to more vigorous workouts.

The Atlanta-based Centers for Disease Control and the Indianapolis-based American College of Sports Medicine adopted the new approach in 1993, then hammered the message home early last year with the formal support of many top U.S. and Canadian researchers. Every adult, they said, should

participate in at least 30 minutes of moderate exercise, such as brisk walking, preferably every day. “Researchers found that the greatest public health benefit occurred when people who were the least fit became at least moderately active,” explains Cora Craig, president of the Ottawa-based Canadian Fitness and Lifestyle Research Institute. “That is where the real difference in mortality rates began to show up.”

The case is far from closed, however.

Last month, the Lawrence Berkeley National Laboratory, a U.S. government research centre, released a report showing that sweating is the only way to attain certain physical benefits. The study of more than 1,800 female recreational runners found that those who ran more than 65 km a week had blood levels of beneficial cholesterol 16 per cent higher than those who ran less than 16 km a week. Study author Paul T. Williams said those results translate into a 29-per-cent reduction in the risk

of coronary heart disease. A handful of other recent studies, including one of more than 17,000 Harvard University alumni, have reached similar conclusions: the more exercise, the better, especially when it comes to extending longevity. “The Centers for Disease Control recom-

Grave consequences The simple fact is that, overall, fit people live longer than unfit. Here is the price of the sedentary life, as measured in death rates from all carnes per 10,000 people. Source: International Health Racquet and Sportsclub Association, from data reported in The Journal of the American Medical Association

mendations show very little benefit for anybody who does much more than the moderate 30 minutes a day,” says Williams. “We are saying that there are substantial benefits beyond that. There has been very little credit given in the past to people going beyond the minimum.” Among all the contradictions, it is worth noting that even some exercise junkies do not believe vigorous workouts are for everyone. Dan Kontak, 41, finds time to run 80 to

90 km a week, even though he has a full-time job in Halifax as a government geologist and has a wife and two small children. But he runs as much for enjoyment as for his health, Kontak says, while many people seem to push themselves harder than they want or even need to. “When I see people huffing and puffing,” he says, “I want to tell them to slow down, and mix walking and jogging—they get the same benefit, and it’s an easier routine to maintain.”

That theme is echoed by exercise professionals. Jack Taunton, co-director of the Sports Medicine Clinic at the University of British Columbia, runs 65 to 70 km a week. But the 48-year-old says most people need just 30 to 40 minutes of exercise three times a week to gain significant health ben-

efits . “They can run or walk or cycle,” he says, “as long as they burn 2,100 calories a week—running or walking 21 miles would use that amount.” And while Taunton agrees that more intense exercise can be helpful, those gains can be offset by socalled overuse injuries, such as tendinitis and stress fractures. “So what may be a piece of cake for one individual may be too much for another,” he says. “Slow walking is a good way to start.”

That, of course, is not the message of the ubiquitous ads for home exercise machines, which fail to mention that acquiring buns of steel requires a will of iron. Not surprisingly, a recent fitness survey by Flare magazine found that 48 per cent of respondents owned sports gear—including home exercise equipment—that they rarely used. There are indications, however, that Canadians are at least trying. Government-funded surveys show that 37 per cent are now exercising enough to gain some cardiovascular benefit, up from about 27 per cent 10 years ago.

They muddle along amid the official confusion, getting up a little earlier to walk to work, trying to hit the gym at lunchtime, or making time to throw a ball around with the kids. Medhat Mahdy, director of membership for YMCA Canada, says he sees more families trying to fit exercise into their day, whether by joining a child for a swim or using a stationary bike while reading or listening to music. “The bottom line is to ease in and do something you enjoy,” he suggests. “Then all the studies can come and go and you’ll know there is no magic elixir. It’s mostly just a matter of common sense.”

PATRICIA CHISHOLM

SHARON DOYLE DRIEDGER