Prescribing Exercise at Varied Levels of Intensity and Frequency: A Randomized Trial
Author(s): Duncan GE, Anton SD, Sydeman SJ, et al.
Citation: Arch Intern Med. 2005;165:2362-2369.
Study Question: Is there a necessary threshold of exercise frequency and intensity necessary to improve cardiovascular risk factors?
Sedentary adults engaged in one of 4 Exercise Regimens:
#1 Moderate intensity 3-4 x/week
#2 Moderate intensity 5-7x/week
#3 Hard intensity 3-4x/week
#4 Hard intensity 5-7x/week
All exercise regimens were for 30 minutes non-stop.
After 6 months and 24 months, they looked at changes in “cardio-respiratory fitness” as well as Total Cholesterol and HDL changes.
They found that Hard Intensity (at least 4 days a week) and Moderate Intensity (5-7 days a week) afforded significant improvement. Moderate intensity 3-4 x/week did not.
They concluded: More intensity and frequency are necessary for metabolic fitness (HDL-C, C-reactive protein, triglycerides, glucose, systolic blood pressure) than cardiopulmonary fitness. Gains in metabolic fitness are usually lost in a few weeks when exercise is not maintained.
Comment: Depending on your age and ability, you should be performing at the highest level you can comfortably achieve. Always be mindful of avoiding injuries and always obey body signals to slow down and/or stop. GLE