Runners and walkers are like dogs and cats. Walkers think runners are abnormally intense, likely to linger too long in sweaty clothes and eventually requiring knee and hip replacements. Runners, by contrast, think walkers are too laid back, never pushing themselves hard enough to get that awesome endorphin rush or the thrill of ending a 12 miler dripping sweat and semi-conscious. So who gets bragging rights health-wise? Is routine walking as effective as running at preventing heart disease across the years?
A recent study investigated this very topic. Williams and Thompson examined data from over 30,000 runners and 15,000 walkers to investigate the effect of differences in exercise mode on cardiovascular disease risk factors such as high blood pressure, high cholesterol, diabetes, and coronary heart disease incidence. Over 6 years of follow-up, authors found that reductions in cardiovascular risk with exercise were not significantly different for running than walking when participants expended approximately the same overall energy (calories) with exercise. In other words, as long as total energy expenditure was similar, the modality and intensity of exercise (running vs. walking) did NOT influence the cardiovascular benefits of physical activity. These results are in agreement with an older finding in 70,000 women from the Nurses’ Health Study. When energy expenditures from moderate walking and more vigorous types of physical activity were similar, both intensities of exercise evoked similar reductions in Type II diabetes risk.
Now, this latter point is important, because it suggests that the calories burned during exercise are more important than the time spent in activity. Achieving similar caloric expenditure with moderate intensity exercise such as walking requires more time spent exercising. Think about it. Walking 4 miles takes almost twice as long as running 4 miles. The caloric expenditure of walking vs. running the same distance is not hugely discrepant, but the time requirement of both intensities of exercise is quite different. To achieve comparable health benefits as running, a walker must be prepared to spend substantially more time in exercise. Therefore, if efficiency is your aim (how can I best maintain my cardiovascular health in the least amount of time?) then vigorous intensity exercise provides the best option. If time isn’t of essence, however, walking appears equally efficacious at reducing cardiovascular risk.
So is walking always as beneficial as running for cardiovascular and metabolic health? Not necessarily. Research from the same data set (runners and walkers) suggests that running evokes greater weight loss over 6 years than walking, even when energy expenditure for the two modalities of exercise is similar. This may be due in part to the finding that post-exercise energy expenditure (the elevated metabolic rate observed after exercise) is much higher after running than walking. And, of course, for many of the other health benefits associated with exercise (e.g., improved cognition), there are not large-scale studies of a similar magnitude comparing the effectiveness of running vs. walking. Regardless, though, it appears that at least with respect to cardiovascular health, runners and walkers can peacefully coexist, assured that they are moving at pace sufficient to keep the heart beating the steady rhythm of good health.