Regular moderate exercise may be the most important thing we can do for ourselves.
Two generations ago, health advice came, not from the Internet and medical journals, but from mothers, grandmothers and kindly old country doctors. It was usually laced with wisdom and folklore—apple a day, cod liver oil, wrap up and avoid colds, fish is brain food, carrots help improve your eyesight —and moderation in all things.
It turns out they were all accurate. How did they know?
Modern science and medicine has concluded that regular fruit consumption is very good for us and fish oils are good for us, that carrots do indeed aid eyesight, that staying warm outside does help avoid infections—and that moderation in all things is very sensible indeed.
It’s that last point that we wish to examine here.
We have established that running, for instance, is generally a healthy idea and people who engage in such exercise regularly do live longer.... But we have also established that more is not better: that distance runners, serious marathoners and iron-man competitors who push themselves to the limit of human endurance, and beyond, may risk damaging their bodies and shortening their lives, just like couch potatoes.
Similarly, the half million or so mature Canadian men and 70,000 women who play recreational hockey are staying fit—but only if they do it regularly. Those who engage in sudden rapid heart rate increases without being reasonably fit, may be risking their lives. Snow shovelling falls into that category as well.
For instance, more than a decade ago a descriptive, cross-sectional study of male participants playing recreational hockey in Sydney, NS, noted: “Although the benefits of exercise are widely recognized, there have also been reports of an increase in frequency of cardiac events and sudden death triggered by vigorous exercise. Regular exercise seems to diminish this risk.”
The study determined: “The physical activity pattern that occurred during recreational hockey caused cardiac responses that might be dangerous to players’ health. More specifically, the players exceeded target and maximum heart rates, had poor heart rate recovery after exercise, and had episodes of nonsustained ventricular tachycardia” (a potentially life-threatening arrhythmia).
Statistically though, some context is required for accuracy.
“Although the relative risk may be significantly increased during strenuous exercise, the absolute risk of sudden death is just 1 per 1.5 million episodes of vigorous exercise. If 500,000 Canadian men each play hockey 30 times a year, this would account for 10 deaths.”
But, while regular exercise will help regulate weight, medical studies are also telling us that the best exercise for weight loss is pushing away from the table… and that controlling weight with exercise while still overeating is a pretty much a losing proposition.
More recently, a huge study of more than 334,000 European men and women concluded a brisk 20-minute walk daily may be all that is required to extend the average person’s life span.
The study found that twice as many deaths may be attributable to lack of physical activity than to obesity. In other words, the fact you may appear a bit overweight, especially after middle age, is less important than whether or not you exercise regularly.
Over an average of 12 years, the researchers measured height, weight and waist circumference, and used self-assessment to measure levels of physical activity. The results were published recently in the American Journal of Clinical Nutrition.
The researchers found the greatest reduction in risk of premature death occurred in the comparison between inactive and moderately inactive groups, judged by combining activity at work with recreational activity.
Slightly less than a quarter of participants were categorized as inactive, in combination with a sedentary occupation. The authors estimate that doing exercise equivalent to just a 20-minute brisk walk each day, burning between 90 and 110 calories, would take an individual from the inactive to moderately inactive group and reduce their risk of premature death by 16 to 30 per cent. The impact was greatest amongst normal weight individuals, but even those with higher body mass index (BMI) saw a benefit.
BMI, however, is really not regarded as a terribly accurate means of assessing fitness because it fails to take natural body type—“big boned” for instance—into account. Some people with a high-ish BMI can be quite healthy. Waist size is actually a better measurement to watch because fat deposition around the middle is a reliable warning sign.
A study of the still quite primitive Hadza tribe in Tanzania determined that they were not, in fact, burning far more calories than the average North American or European. The Hadza’s average metabolic rate, or the number of calories that they were burning over the course of a day, was about the same as the average metabolic rate for Westerners.
The implication, the scientists concluded, is that active, traditional lifestyles may not protect against obesity if people overeat—that even active people will pack on pounds if they consume too many calories.
Yet another recent study has shown that moderate physical activity appears to reduce death rates among men diagnosed with localized prostate cancer. This 15-year study looked at 4,623 men in Sweden, who were diagnosed with localized prostate cancer between 1997 and 2002, and followed them until 2012.
Analysis showed that men who did the equivalent to walking or cycling for 20 or more minutes a day were 30 per cent less likely to have died from any cause, and 39 per cent less likely to have died of prostate cancer.
Such studies are numerous, but there appears to be a strong consensus developing that moderate, but regular, exercise is a much more significant indicator of the odds of longevity than weight alone.