Exercise Amount May Be More Important than Intensity -- MEDICA - World Forum for Medicine

“The classic exercise regimen has a component of intensity up to 80 percent of someone’s maximum for health benefits. Our study demonstrates that you can exercise at an intensity much less than that and still achieve fitness benefits,” said lead author Brian D. Duscha, Duke University Medical Center, Durham, North Carolina.

Researchers from Duke University Medical Center examined the effects of different exercise training regimens on 133 sedentary, overweight, nonsmoking patients, ages 40 to 65 years, who had abnormal levels of fat in their blood. Patients were divided into four exercise groups: high-amount/high-intensity (HAHI), the equivalent of jogging 20 miles per week at 65 to 80 percent peak VO2; low-amount/high-intensity (LAHI), the equivalent of jogging/walking up an inclined treadmill approximately twelve miles per week at 65 to 80 percent peak VO2; low-amount/moderate intensity (LAMI), the equivalent of walking approximately twelve miles per week at 40 to 55 percent peak VO2; and a control group of nonexercising patients. All patients underwent cardiopulmonary exercise testing twice at baseline and after seven to nine months of exercise training.

All exercise groups significantly improved their absolute and relative peak oxygen consumption and time to exhaustion (TTE) compared to baselines scores. Although the HAHI group showed the greatest improvements in peak VO2 overall, increasing exercise intensity from 40 to 55 percent to 65 to 80 percent (at a controlled amount of twelve miles/week) did not significantly improve peak oxygen consumption, yet increasing the amount of exercise did produce improvements. An increase in exercise amount also demonstrated a graded increase in TTE between groups, although data were not statistically significant.

Body mass index (BMI) was reduced in the LAHI and HAHI, groups but remained unchanged in the LAMI group. All exercise groups lost an average of 2.87 pounds after exercise.

MEDICA.de; Source: American College of Chest Physicians (ACCP)