Personal trainers often have female clients over the age of 40 who have similar complaints about losing muscle mass and gaining body fat. Although these changes aren’t unexpected and can be a normal part of the aging process, they are not inevitable. In fact, the right resistance-training program can positively affect body composition by reducing fat, maintaining and building muscle, and increasing strength in this population.
One of the primary reasons a woman’s body changes with age is because estrogen levels decline (Collins et al. 2019). Estrogen is vital to women’s health and was recently determined to be the key factor in muscle health for women over 40. The hormone works with muscle satellite cells to maintain, repair and build healthy muscles, and estrogen-rich cells are critically important to the preservation of muscle function (Collins et al. 2019). When estrogen is depleted, the muscle satellite cells’ ability to sustain and regenerate muscle fibers is severely limited, leading to gradual losses in muscle mass and strength as well as an increase in body fat.
Although most aging women experience changes in estrogen levels and body composition, research reveals that specific methods of resistance training can help preserve muscle mass and strength.
The first consideration when programming resistance training moves for women over 40 is training load, or amount of work. Training load depends on total frequency (days per week), volume (amount per session) and intensity (degree of difficulty) of training over time. Personal trainers who learn to understand training load and how to best use it have an important tool that empowers them to facilitate calculated and desired body composition changes in women over 40.
There are two types of training loads: external and internal. External training load reflects the amount of work done over time. It is defined by exercise type, such as machine-based resistance training or plyometric exercises, and by session frequency, number of sets and repetitions, and exercise intensity. External training load is an indicator of expected changes in response, such as growth and strength improvements (Ashmore 2019).
While external training load reflects the type and amount of exercise, internal training load characterizes the client’s physiological and psychological responses to exercise during and after training. Common measures of internal training load and the body’s response to it include heart rate, blood lactate levels, oxygen consumption and rating of perceived exertion (Ashmore 2019).
Although training load is defined and measured similarly across all populations, external training load recommendations for women over 40 differ from those for other groups. Since estrogen loss directly influences muscle tone, strength and appearance in these women, estrogen-dependent changes affect and determine their training load recommendations.
The most notable difference in training load guidelines for women over 40 is greater volume. Research has shown that middle-aged women benefit more from higher-volume training programs than from lower-volume, high-intensity programs. When Burrup et al. (2018) examined the resistance training habits of 109 women over 40, results showed that for each day per week of strength training, body fat decreased by 1.3 percentage points and muscle mass increased by 656 grams. The findings indicated that the more days women devoted to resistance training, the lower their body fat and the higher their fat-free mass tended to be—even after accounting for differences in age, energy and protein consumption.
In a similar study (Cunha et al. 2019), researchers compared the effects of two different whole-body resistance training programs on body fat and blood biomarkers in 65 untrained women over age 60. Both groups performed 12 weeks of strength training using eight different exercises with 10–15 repetitions per move. The difference between the programs was that the low-volume group performed one set per exercise, while the high-volume group performed three sets. Results showed that the high-volume group saw greater improvements in blood biomarkers, percent body fat and trunk fat compared with the low-volume group, demonstrating the value of higher-volume resistance training for women over 60.
One thing to note is that higher-volume resistance training programs do create a dilemma. Any time you increase volume, it puts the client at greater risk for overtraining and injury. Therefore, exercises used in a high-volume program need to be well-thought-out in advance. For this reason, it is worth revisiting the value of single-joint exercises in an effort to prevent overtraining and to maintain good form, target specific muscles and leave adequate rest days while increasing frequency and volume.
Although multijoint exercises tend to be favored—to save time and to boost performance factors, such as heart rate and total oxygen consumption—single-joint moves have been shown to be as effective in inducing positive body composition changes. In one study (Paoli et al. 2017), researchers examined the effects of single-joint exercises versus multijoint exercises on body fat and muscle mass. The results: Both multijoint and single-joint moves decreased body fat and increased fat-free mass, with no significant differences between the protocols.
When planning how to boost training load, consider the value of isolation exercises. For example, program leg extensions, leg curls, lateral shoulder raises, triceps extensions, leg abductions/adductions and hip bridges to create effective routines.
Programming high-volume sessions can be tricky, especially when the client is new to resistance training or hasn’t been exercising regularly. As noted, the risk of overtraining is inherent, whether you raise frequency or increase the amount of training per session. Fatigue can also be a factor and may negatively affect exercise mechanics; however, there are two emergent methods that work well with high-volume resistance training and with clients who are new to strengthening their bodies: cluster-set training and redistributed-rest training.
Cluster-set training uses short rest periods within sets instead of longer rest periods between sets. For example, a traditional program might include three sets of 15 repetitions per exercise, with 30 seconds of rest between sets. In an equivalent cluster-set program with three 15-rep sets, there would be rest after every third or fifth repetition of each set.
Researchers found that muscle performance improved more with cluster sets than with traditional sets and that clusters were an effective way to change up workouts and use rest periods to safely increase resistance training volume (Oliver et al. 2013). Cluster-set training is a good choice for clients who are new to resistance training, because the shorter rests within sets allow for mini muscle-recovery breaks that stave off fatigue and associated errors in form.
In a subsequent study, researchers suggested an entirely new way to train—with equal rest after each repetition. This approach is known as redistributed-rest training (Tufano et al. 2017). In the Tufano study, participants did one set of 36 repetitions of a single exercise. Results showed that when total rest time was redistributed equally between repetitions, muscle force output and mechanics were more constant. The data also suggested that redistributing rest can be a creative programming tool for improving muscle performance while safely increasing volume.
Be sure to reduce the intensity of the load or weight when increasing volume during a set. Although the principle of redistributed-rest training is to allow the muscle moments of recovery between repetitions, and thus during the set, it is still important to remember that the client is performing 36 repetitions in quick succession, which can cause fatigue and errors and, over time, lead to overtraining.
In alignment with current recommendations, at least 48 hours of rest is required for a muscle to recover fully after a workout. The 48-hour rule provides a good rationale to alternate training days, focusing on similar sets of muscles one day and other muscles the next, or to alternate resistance training days with active-recovery activities, such as swimming, low-intensity cardiovascular exercise and dynamic stretching.
Load for Results
Women over 40 are a unique client group and, whether they are new to resistance training or have been exercising regularly, training-load recommendations are similar and suggest that high-volume resistance training improves muscle mass and decreases body fat. The best practice is to increase the frequency of training on alternate days and to boost volume by combining multijoint and single-joint exercises using either the cluster-set or redistributed-rest training methods.
Programming: Trainer’s Tips
- Intensity will vary depending on the client’s fitness level and resistance training experience.
- The recommended starting place for clients who are new to resistance training is 45% of one-repetition maximum.
- In the study, researchers used 36 continuous repetitions; however, you may substitute two sets of 18 reps.
- With an increase in frequency, the suggested total training time per session is 45 minutes.
- Whole-body training routines were used in the research; however, be cautious when increasing training frequency, and include a 48-hour rest period between sessions per muscle group.
Resistance Training: Sample Workout
This is a sample routine for redistributed-rest training. Note the rest intervals between repetitions.
Ashmore, A. 2019. Timing Resistance Training: Programming the Muscle Clock for Optimal Performance. Human Kinetics: Champaign, IL.
Burrup, R., et al. 2018. Strength training and body composition in middle-age women. The Journal of Sports Medicine and Physical Fitness, 58 (1–2), 82–91.
Collins, B.C., et al. 2019. Estrogen regulates the satellite cell compartment in females. Cell Reports, 28 (2), 368–81.
Cunha, P.M., et al. 2019. Comparison of low and high volume of resistance training on body fat and blood biomarkers in untrained older women: A randomized clinical trial. The Journal of Strength Conditioning Research, doi:10.1519/JSC.0000000000003245.
Oliver, J.M., et al. 2013. Greater gains in strength and power with intraset rest intervals in hypertrophic training. The Journal of Strength and Conditioning Research, 27 (11), 3116–31.
Paoli, A., et al. 2017. Resistance training with single vs. multi-joint exercises at equal total load volume: Effects on body composition, cardiorespiratory fitness, and muscle strength. Frontiers in Physiology, 8, 1105.
Tufano, J.J., et al. 2017. Effects of cluster sets and rest-redistribution on mechanical responses to back squats in trained men. Journal of Human Kinetics, 58, 35–43.