Mild exercise increases fitness and cuts cardiovascular risk

With the beginning of a new year, many people are interested in improving their
fitness and health. However, exercising can be a daunting task if a person has
been sedentary. Also, it is often the belief that to get benefit one must employ the
slogan, “no pain, no gain.” This frequently results in frustration and failure to
exercise consistently. Fortunately, though, research has shown that mild to
moderate exercise does provide significant health and fitness benefits, especially
in those who are overweight and sedentary.

A study conducted at Duke University and published in the journal Chest compared the
effects of three different exercise regimens on fitness improvements in overweight men
and women who were at risk for heart disease.

Broken into four groups, the volunteers either did not exercise, walked briskly for 12
miles a week at a moderate intensity, walked briskly or jogged slowly 12 miles a week at
a vigorous intensity, or jogged 20 miles a week at a vigorous intensity.

Two measurements of fitness – time to exhaustion and oxygen consumption – were
measured before and after 7 to 9 months of training.

All exercise groups saw fitness improvements compared to baseline. Results indicated
that two to three hours of mild exercise a week at a moderate intensity is sufficient to
increase aerobic fitness and cut the risk of cardiovascular disease. Increasing either
the intensity or the amount of exercise provided additional improvements in fitness.

Although more vigorous exercise should still be encouraged for maximum benefit, this
study demonstrates that it is appropriate to recommend mild exercise to improve fitness
levels and reduce cardiovascular disease risk, especially in those who are overweight
and sedentary.

Chest. 2005;128:2788-2793.