The first question most sedentary clients have when considering beginning an exercise program is, “How much do I have to do to get results?” Those who have been sedentary for long periods of time may not intrinsically enjoy physical activity, therefore may not be driven to exercise for reasons of pleasure and enjoyment. Other reasons often cited for not exercising are a lack of time, not knowing what to do or how often to do it, and medical problems that render conventional structured exercise classes risky. A new study sheds light on the question of exercise session frequency for older women just starting an exercise program.
The Physical Activity Guidelines for Americans stipulate that fit adults over the age of 65 who have no limiting chronic conditions should do at least 150 minutes a week of moderate-intensity aerobic exercise, 75 minutes a week of vigorous exercise, or a combination of the two. The Public Health Agency of Canada recommends that all adults over 65 should ideally accumulate 2.5 hours per week of aerobic exercise, and include at least two sessions per week of strength training.
A study by the American College of Sports Medicine investigated the effect of the following three combinations of aerobic exercise and resistance/strength training for 72 previously sedentary, unfit older women aged 60-74: 1 + 1 day per week each of aerobic and resistance training; 2 + 2 days per week of each; and 3 + 3 days per week of each. The study lasted 16 weeks. The researchers looked at how each training regimen influenced muscular strength, cardiovascular fitness, total daily energy expenditure, non-exercise activity thermogenesis (the energy utilized engaging in physical activity that was not structured exercise), feelings of fatigue/depression/vigour, and pro-inflammatory cytokines. Cytokines regulate the body’s responses to infection, inflammation and trauma. Pro-inflammatory cytokines worsen a disease, while anti-inflammatory cytokines promote healing. The results of the study were very different than what people expected:
- Aerobic capacity – After 16 weeks all the groups significantly increased aerobic capacity, and no statistically significant differences were noted between the three groups.
- Body composition – All groups significantly lost weight (3 lbs on average), reduced body fat, and gained muscle mass. Again, there were no statistically significant differences between the three groups.
- Muscular strength – Upper and lower body strength increased significantly, with no statistical differences between the groups.
- Total daily energy expenditure and non-exercise activity thermogenesis – Interestingly, the 2 + 2 group improved the most on these measures, whereas the 1 + 1 and 3 + 3 groups did not. It can be surmised that exercising 6 times per week (the 3 + 3) group, results in fatigue that led to a decrease in other types of activities.
- Feelings of fatigue and depression, and pro-inflammatory cytokines – These variables improved but there were no significant differences between the three groups.
For unfit women just beginning to exercise, two session a week each of aerobic and strength training appears to be as effective as a more demanding protocol. Bear in mind that these results apply only to deconditioned, previously sedentary women, and to the initial 4 months of an exercise program.
YWCA Fitness on 25th is a coed facility providing a range of fitness experiences in a welcoming environment to achieve your individual health and fitness goals. Watch for the next WYCA wellness article on our website blog and social media channels.
By Nima Nazemi
Reference: Jennifer Salter, 2016, ‘Aerobic Exercise and Strength Training for Older Women: What is the Optimal Starting Dose?’, Canfitpro Magazine, September/October 2016, p. 50-51.