An effective fitness program revolves around understanding the “dose-response relationship” of exercise. When contemplating an exercise program, we often focus on, “what should I do?” We must also consider: How often? For how long? How hard? The “dose-response relationship” delineates: What is the proper dose of exercise (the frequency, duration, and intensity) that will elicit the desired response (improved body composition, cardio-respiratory fitness, muscle strength, etc.)? Analogous to the prescription of a drug, too small of a dose, and no effect is produced. Likewise, too large of a dose results in toxicity. Zeroing in on the appropriate dose-response relationship is a paramount pursuit of the exercise scientist.
A brand new study that will soon be published in Medicine and Science in Sport and Exercise sheds much needed light on the question of “how often?” Researchers from the University of Alabama studied the effects of various frequencies of strength and aerobic exercise in older women. Study participants were randomly assigned to one workout per week, two workouts per week, or three workouts per week (each workout consisted of approximately 30 minutes of “cardio” followed by 30 minutes of strength training). Interestingly, researchers discovered that one workout per week was just as effective in improving aerobic fitness and muscle strength. Also of interest, women who exercised three times per week experienced a reduction in NEAT (Non-Exercise Activity Thermogenesis; essentially the amount of calories we expend all day long outside of exercise). Stated otherwise, women who exercised three times per week actually had a reduction in how many calories they expended. Unfortunately, people who still subscribe to the “more is better” mantra will ignore the massive implications of this study. This study provides evidence that not only is more NOT better… but more is actually worse when it comes to increasing our ability to burn calories. It is important to note that the results of this study specifically apply to women over the age of 60, although there is no reason to believe that similar results wouldn’t be produced in a variety of different populations.