Researchers at the University of Alabama at Birmingham monitored 63 women performing combined aerobic exercise training (AET) and resistance exercise training (RET) for 16 weeks.
One group performed AET and RET one time per week, a second group two times per week and a third group three times per week.
The study found significant increases in muscular strength, cardiovascular fitness and functional tasks in each group, but there were no significant differences in outcomes among groups.
Fisher said the study goes against what most people believe about exercise - that more is better.
Greater frequency, intensity and duration of exercise training have been shown to be beneficial in younger adults.
This study suggests that the progressive overload that benefits a younger demographic may not necessarily apply to all aspects of health and fitness in women over the age of 60.
For example, at the beginning of the study, each participant completed a 4km-per-hour walk test to determine heart rate and oxygen consumption during the task. The average heart rate was 110 beats-per-minute.
After 16 weeks of AET and RET training, the women's heart rates averaged 92 beats-per-minute during the walk, indicating that the women required much less effort to do the same daily task following the exercise programme.
Fisher suggested that a low-frequency, combined AET/RET programme may be an ideal method of training to optimise strength and endurance, as well as improving quality of life in older adults.