According to a new study, a non-strict approach to scheduling workouts may actually be more beneficial than working out almost daily.
The study, published in the journal Exercise & Science in Sports & Medicine, investigated how many times per week exercise is best. Researchers at the University of Alabama at Birmingham gathered 72 older (60-74 years old), sedentary women and randomly assigned them to one of three exercise groups.
The researchers were hoping to find out which number of weekly workouts would be just right for increasing the women’s fitness and overall weekly energy expenditure.
One began lifting weights once a week and performing an endurance-style workout, like jogging or bike riding, on another day, totaling two workouts per week. The second group lifted weights twice a week and jogged or rode an exercise bike twice a week, totaling four workouts. The third group completed three weight-lifting and three endurance sessions, totaling six weekly workouts.
Aerobic training consisted of 40 minutes of aerobic exercise at 80 percent maximum heart rate and resistance training consisted of 2 sets of 10 repetitions for 10 different exercises at 80 percent of one repetition maximum.
Over the duration of four months, the intensity and duration gradually increased, until the women were jogging moderately for 40 minutes and lifting weights for about the same amount of time.
Body composition (DXA), feeling of fatigue, depression, and vigor (questionnaire), strength (1RM), serum cytokines (ELISA), maximal oxygen uptake (progressive treadmill test), resting energy expenditure, and total energy expenditure (TEE) were measured before and after 16 weeks of training.
All groups increased fat free mass, strength and aerobic fitness and decreased fat mass. TEE and AEE increased with the group that worked out four times per week but not with the other two groups. Nonexercise training AEE (NEAT) increased significantly in the four times per week group (+200 kcal/day), the two times per week group showed a trend for an increase (+68 kcal/day) and the six times per week group actually decreased significantly (-150 kcal/day).
The results indicate that working out six times per week may inhibit NEAT by being too time consuming. Working out four times per week seemed to be the most effective and efficient routine.
The fundamental finding of this study, according to the lead author, is that “less may be more,” a message that most likely resonates with far more of us. The women exercising four times a week had the greatest overall increase in energy expenditure”. But those working out only twice a week “weren’t far behind.”