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Is pumping iron really necessary?
Is pumping iron really necessary? Look around most gyms and you’ll probably conclude that if you don’t pump iron you’re not doing a complete workout. But is that really true? Several studies have suggested a link between muscle strength and living longer, but for a long time it was unclear whether other factors were confusing the picture. People who are muscular are more likely to be thin, aerobically fit and generally healthy – all features known to extend lifespan. In the past few years, however, some large, well-designed studies have settled the question. One study, published in 2008, measured the muscle strength of almost 9000 American men and followed their health for 20 years. The death rates among those whose muscle strength was in the bottom third for
their age group was around 30 per cent higher than for the other two-thirds (BMJ, vol 337, a439). That link remained even after the results had been adjusted to take account of the effects of aerobic fitness. “The bottom line is that both strength and aerobic fitness make independent contributions to health,” says Steve Blair, one of the study’s co-authors, based at University of South Carolina’s Arnold School of Public Health, who helped write the US national guidelines on exercise. In the 2007 update of its own recommendations on exercise, the American College of Sports Medicine added two episodes of strength training a week, consisting of about 10 repetitions of 10 strengthening exercises of all the major muscle groups.
Cross-country skiing (uphill) Swimming (fast crawl) Rowing (over 9 km/h)
10
11
12
13
14
Running up stairs
15
16
Metabolic equivalent (MET)
”Risk of a heart attack during jogging does rise, but pales into insignificance beside its overall lifetime benefits”
17
SOURCE: UNIVERSITY OF SOUTH CAROLINA
Jogging can kill you ou “Look at Jim Fixx!” cry the couch potatoes, citing the celebrity runner credited with kick-starting the jogging craze in the 1970s. At the age of 52, Fixx famously dropped dead from a heart attack midway through a run. Could exercise be a killer lying in wait for the unwary? The risk of a heart attack does rise g during vigorous exercise like jogging or shovelling snow. But the extent off the rise depends heavily on how accustomed you are to that exercise. For someone who is completely unfit, the risk can rise by as much as 100fold, relative to when they are resting. For someone who regularly runs five times a week, their risk while exercising roughly doubles. The lesson, says David Stensel, an exercise physiologist at Loughborough University in the UK, is to be careful when you take up exercise. He advises gradually building up the intensity and duration of your exercise sessions, and that you have a medical check-up if you are over 35 and are not
used to regular physical activity. Stensel points out that the raised risk, which lasts ffor the duration of the exercise and up to half an hour after it, pales into insignificance beside the overall lifetime benefits of regular exercise. Study after study has shown that keeping active lowers an individual’s risk of suffering a heart attack by 50 to 80 per cent. That protective effect stays with you day and night – whether you are running a marathon or asleep in bed. There are a myriad other health benefits too. “You’re far better off exercising than worrying about your risk of heart attack during exercise,” says Stensel.
9 January 2010 | NewScientist | 37
their age group was around 30 per cent higher than for the other two-thirds (BMJ, vol 337, a439). That link remained even after the results had been adjusted to take account of the effects of aerobic fitness. “The bottom line is that both strength and aerobic fitness make independent contributions to health,” says Steve Blair, one of the study’s co-authors, based at University of South Carolina’s Arnold School of Public Health, who helped write the US national guidelines on exercise. In the 2007 update of its own recommendations on exercise, the American College of Sports Medicine added two episodes of strength training a week, consisting of about 10 repetitions of 10 strengthening exercises of all the major muscle groups.
Cross-country skiing (uphill) Swimming (fast crawl) Rowing (over 9 km/h)
10
11
12
13
14
Running up stairs
15
16
Metabolic equivalent (MET)
”Risk of a heart attack during jogging does rise, but pales into insignificance beside its overall lifetime benefits”
17
SOURCE: UNIVERSITY OF SOUTH CAROLINA
Jogging can kill you ou “Look at Jim Fixx!” cry the couch potatoes, citing the celebrity runner credited with kick-starting the jogging craze in the 1970s. At the age of 52, Fixx famously dropped dead from a heart attack midway through a run. Could exercise be a killer lying in wait for the unwary? The risk of a heart attack does rise g during vigorous exercise like jogging or shovelling snow. But the extent off the rise depends heavily on how accustomed you are to that exercise. For someone who is completely unfit, the risk can rise by as much as 100fold, relative to when they are resting. For someone who regularly runs five times a week, their risk while exercising roughly doubles. The lesson, says David Stensel, an exercise physiologist at Loughborough University in the UK, is to be careful when you take up exercise. He advises gradually building up the intensity and duration of your exercise sessions, and that you have a medical check-up if you are over 35 and are not
used to regular physical activity. Stensel points out that the raised risk, which lasts ffor the duration of the exercise and up to half an hour after it, pales into insignificance beside the overall lifetime benefits of regular exercise. Study after study has shown that keeping active lowers an individual’s risk of suffering a heart attack by 50 to 80 per cent. That protective effect stays with you day and night – whether you are running a marathon or asleep in bed. There are a myriad other health benefits too. “You’re far better off exercising than worrying about your risk of heart attack during exercise,” says Stensel.
9 January 2010 | NewScientist | 37