As average life expectancy for women continues to increase, quality-of-life issues come to the fore. Expanded life spans are encouraging new research into menopause—a life change that all women experience. About 35–40 million women in the United States are past menopause or currently going through it, and the Baby Boom Generation will likely add another 20 million in the upcoming years (Kelch 1998). As a fitness professional, you can expect to see an increase in program design issues related to menopausal women. Prospective clients may present issues such as weight gain, hot flashes or fatigue. What do you need to know to successfully help your clients navigate through the stages of menopause?
Menopause literally means the permanent “pause” of menses, which signifies the end of a woman’s ability to have children. Typically, menopause is a gradual process in which the ovaries reduce their production of female sex hormones. Most women experience natural menopause when they are between 40 and 58 years old, with the average age of onset being around 51 years (North American Menopause Society [NAMS] 2006). It is interesting to note that while the average life expectancy of women has increased, the average age of menopause onset has remained the same for centuries.
Menopause terminology is often misused and can be confusing to clients who are experiencing the transition. In addition, the stages of menopause are not distinct; rather, they overlap each other. The World Health Organization defines the stages of menopause in the following way (International Menopause Society 1999):
Every woman’s experience with menopause is distinct. Some women report no physical or physiological changes at all, whereas others have immense difficulties. Possible changes include an irregular menstrual cycle, hot flashes, sleep disturbances, mood swings, urogenital symptoms and weight gain. While most of these changes occur in direct relation to the onset of menopause, weight gain appears to be related mostly to lifestyle, with menopause as a contributing factor. Sternfeld et al. (2004) studied more than 3,000 women who were participating in the Study of Women’s Health Across the Nation (SWAN) to determine the relationship of aging, menopausal status and physical activity to weight and waist circumference. These researchers found that menopausal status was not a risk factor for weight gain or waist circumference, but the increase in age was. They also determined that higher physical activity levels, both in terms of sports/exercise and daily routine activity, were associated with a lower risk of both increased waist circumference and substantial weight gain.
It’s likely you will have clients approach you for help with changes that occur during menopause. While the menopause research in relation to symptom reduction, hormone replacement therapy and the benefits of exercise is still emerging, you are in a strong position to assist menopausal clients in achieving their health and fitness goals.
The majority of women in the United States (more than two-thirds) report experiencing unpleasant symptoms during menopause (NAMS 2006). The symptoms stem from alterations in estrogen and progesterone levels; as the ovaries become less functional, they produce fewer hormones and the body responds accordingly. Specific symptoms and their significance (mild, moderate or severe) vary widely from female to female and are typically classified as vasomotor, somatic or psychological.
Vasomotor symptoms include hot flashes, night sweats and urogenital changes such as vaginal dryness or atrophy; somatic symptoms are characterized by tension, anxiety, irritability and moodiness; and psychological symptoms include depression, low self-esteem and emotional instability. Only vasomotor symptoms have been directly linked to the hormonal changes occurring during menopause.
Numerous studies have found that physically active women self-report fewer menopausal symptoms. One recent study found that women who were more physically active reported significantly less severe vasomotor and somatic symptoms; and while the difference between groups was not significant, the more active women also reported less frequent symptom occurrences (Elavsky & McAuley 2005). However, self-reported research has also found that physical activity status does not attenuate menopausal symptoms (Sternfeld, Quesenberry & Husson 1999).
Very few studies within the literature have investigated the effects of an exercise intervention on menopausal symptoms. Kemmler et al. (2005) found that insomnia, migraines and mood changes were modestly reduced in early postmenopausal women, but there were no changes in hot flashes or depression following a 3-year, 4-times-per-week exercise program. Aiello et al. (2004) also found no improvements in vasomotor symptoms following a 12-month exercise intervention; a few women even experienced an increase in symptoms.
While the current research is contradictory, the hypothesis that physical training may improve vasomotor symptoms is related to endogenous opiate production. It has been suggested that lower levels of the neurotransmitter beta-endorphin, associated with a decrease in estrogen levels, are the underlying mechanism of vasomotor symptoms. Beta-endorphin, an endogenous opiate, is also known to affect thermoregulation in the human body. Vigorous exercise training elevates beta-endorphin levels, which in turn should reduce vasomotor symptoms. As further research is conducted, we should begin to have a clearer understanding of the effects of exercise training on menopausal symptoms.
Heart disease is the number-one killer of American women, and as women enter menopause, the risk of cardiovascular and metabolic diseases increases (American Heart Assocation [AHA] 2007). Atherosclerosis and coronary heart disease rise sharply in women during their postmenopausal years, owing to increased serum total cholesterol and low-density lipoprotein cholesterol, decreased high-density lipoprotein cholesterol, weight gain, increased abdominal fat distribution and decreased physical activity (Astrup 1999). Researchers hypothesize that the changes in these risk factors are related in part to the decrease in estrogen production, coupled with lifestyle changes.
Osteoporosis is characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures. Of the 10 million Americans estimated to have osteoporosis, 8 million are women and 2 million are men. Osteoporosis is responsible for more than 1.5 million fractures annually, including over 300,000 hip fractures; approximately 700,000 vertebral fractures; 250,000 wrist fractures; and 300,000 fractures at other sites (National Osteoporosis Foundation 2006).
Bone is a dynamic tissue that is constantly undergoing a bone-remodeling process of breakdown (resorption) and formation (deposition of new bone). The purpose of the bone-remodeling process is to maintain calcium homeostasis and replace older bone. As a woman enters menopause, she becomes more susceptible to bone loss and subsequent fractures due to the estrogen loss. Exercise training has been shown to improve bone density. Bone responds to mechanical strain by increasing bone mass—stimulating a higher rate of formation rather than resorption. In other words, bones, like other tissues, adapt to stress placed upon them.
A decade ago, hormone replacement therapy was routinely prescribed to help relieve menopausal symptoms, protect against heart disease and delay osteoporosis, but this is no longer the case. The Women’s Health Initiative (2004) and the Nurses’ Health Study (2006) both published results that led to confusion among women as to the safety of hormone therapy.
In 2002, the Women’s Health Initiative—a major study of hormone therapy (estrogen plus progesterone)—was cut short by the National Institutes of Health (NIH) because results were demonstrating an increased risk of heart attacks, stroke, blood clots and breast cancer in women taking the hormones (Women’s Health Initiative 2004). In March 2004, the NIH announced it had also stopped the estrogen-alone study in the interest of safety. The researchers determined that women taking estrogen alone had an increased risk of stroke and blood clots and experienced no clear effect vis-à-vis heart disease or breast cancer.
After the estrogen-plus-progesterone study was discontinued, the AHA updated its Guidelines for Cardiovascular Disease Prevention in Women, offering new recommendations for postmenopausal hormone therapy (PHT) (AHA 2007). The guidelines included the following:
- Women with heart disease should not be given PHT in an effort to prevent further disease.
- Women who are already on PHT and have heart disease should continue only if there is a good reason other than heart disease to do it.
- Data is not strong enough to suggest that healthy women should start PHT to prevent heart disease.
Another outcome of the Nurses’ Health Study was the relationship between the time elapsed since menopause and the age at which hormone replacement was initiated. Women who began taking hormones (estrogen alone or estrogen with progesterone) within 4 years of menopause experienced a 30% lower risk of coronary heart disease, compared with postmenopausal women who never used hormones. The benefit was not realized if a woman began hormones long after menopause (≥10 years) or was older (60+ years) (Grodstein, Manson & Stampfer 2006). These results were similar to those found in the Women’s Health Initiative. Researchers cautioned against using postmenopausal hormones long-term for chronic-disease prevention, given the risks of stroke, pulmonary embolisms and possibly breast cancer that had been observed in other studies.
Newer estrogen therapies, such as selective estrogen receptor modulators (SERMs), are effective in treating osteoporosis without increasing the risk of breast cancer, but they do not reduce menopausal symptoms. Research is currently underway to determine their effects on heart disease. Note that it is not within a fitness professional’s scope of care to make recommendations concerning a client’s decision about hormone therapy. This decision is between the client and her physician.
Exercise training is instrumental in protecting menopausal women against heart disease and osteoporosis. The following research review explores relevant studies on the subject and suggests exercise programming tips for a menopausal client.
Most cardiorespiratory research involving menopausal and postmenopausal women have focused on how aerobic activity affects body composition and abdominal fat distribution. Adipose tissue deposited in the abdominal region plays an important role in the occurrence of hyperlipidemia, diabetes, hypertension and atherosclerosis.
Many studies have used walking as the primary mode of aerobic activity. In one such study, postmenopausal women (55–66 years) wore pedometers for 14 days to determine whether body composition variables differed across activity levels. Research determined that women who accumulated more steps per day (≥7,500) had more favorable body composition—including lower body fat percentage, trunk fat, body mass index (BMI), waist and hip circumferences and waist-hip ratio—than women who took fewer steps (Krumm et al. 2006). Irwin et al. (2003) provided study participants (50–75 years) with a 45-minute, 5 days- per-week walking program that lasted for 1 year. Participants experienced significant decreases in intra-abdominal fat, total body fat and body weight.
A recent study that reported changes in cardiorespiratory performance looked at whether a single or double bout of daily walking was better for walking performance in postmenopausal participants (48–63 years) (Asikainen et al. 2006). A “continuous” exercise group walked for approximately 48 minutes per session, while a “fractionated” exercise group walked for approximately 24 minutes twice per session. Each group walked at 65% of VO2max 5 days per week. Results showed that walking speed, a marker of improved cardiorespiratory performance, increased equally in the two exercise groups compared with the control group. Asikainen et al. (2002) demonstrated an almost 10% improvement in VO2max in sedentary, postmenopausal women following a 24-week walking program at 45%–55% of VO2max with a total weekly energy expenditure of 1,000–1,500 kilocalories.
Practical Advice: The goal of a cardiorespiratory fitness program should be to improve the client’s aerobic conditioning and body composition. Choose a weight-bearing activity, such as walking, to help protect bone density.
Numerous researchers have reported on the effects of resistance training for menopausal women. Positive outcomes included improvements in strength, body composition and bone density. Improvements of approximately 30% in the lower body and 25% in the upper body occurred in postmenopausal women following a 6-month resistance training protocol consisting of 8 repetitions of 12 exercises at 80% of one-repetition maximum (1RM) (Bemben et al. 2000).
Researchers have determined that resistance training in postmenopausal women also has a positive effect on body composition. Figueroa et al. (2003) had 94 sedentary postmenopausal women (40–65 years) perform 2 sets of exercises at 70%–80% 1RM using machines and free weights, plus 25 minutes of weight-bearing cardiovascular exercise, 3 days per week for 12 months. They determined that exercise training significantly increased total-body and regional lean soft-tissue mass and decreased leg fat mass. Teixeira et al. (2003) likewise found that postmenopausal women who performed 2 sets of 6–8 repetitions at 70% 1RM (2 days) and 80% 1RM (1 day), as well as circuit training with moderate-impact, weight-bearing activities (e.g., hopping, skipping, etc.), for 1 year experienced a significant and positive effect on lean soft-tissue changes and a significant decrease in leg fat tissue.
Resistance training programs have consistently shown improvements in bone density. Pruitt et al. (1992) showed an improvement in lumbar bone mineral density (BMD) following a 9-month weight training program. Kerr et al. (2001) recorded an increase in hip BMD after a 2-year progressive strength training program. The Bone Estrogen Strength Training (BEST) study examined the effects of weight-bearing and resistance training on BMD in postmenopausal women (Cussler et al. 2003). Participants trained 3 days per week for 1 year. The training program consisted of a warm-up, eight weightlifting exercises, a moderate-impact weight-bearing circuit and weighted vests. The women completed two sets of 6–8 repetitions at 70% 1RM (2 days) and 80% 1RM (1 day). The results showed that women who lifted more weight experienced greater improvements in bone density; intensity was more important than repetitions for adaptation to skeletal tissue.
Practical Advice: Improvement in BMD is site-specific. Only those bones attached to the exercising muscles are affected, owing to specificity of stimulation. Therefore, choose exercises to strengthen the small and large muscle groups of the spine and hip, the most common sites of osteoporotic fractures. In addition, pick exercises that help with posture and realign the spine and pelvic girdle (e.g., upper-back and leg/hip exercises).
Flexibility research targeting menopausal women is severely lacking. In the published studies, flexibility training is typically combined with aerobic dance and/or resistance training and shows improvements of 5%–25% or no effect at all (Asikainen, Kukkonen-Harjula & Miilunpalo 2004). Since the research is not pure—meaning flexibility is not the sole mode of activity—it is very difficult to make definitive conclusions as to the effectiveness of flexibility training in postmenopausal women. We cannot be sure if it was the flexibility training, the other mode of activity or a combination of factors that caused range-of-motion improvements. Much more research is needed in this area to determine the appropriate exercise design for menopausal women.
Practical Advice: Until there is a clearer understanding of the most appropriate flexibility design, follow the American College of Sports Medicine’s (ACSM) flexibility guidelines for clients. ACSM recommends performing a static stretching routine that exercises all major muscle groups at least 2–3 (preferably 5–7) days per week, holding each stretch for 15–30 seconds to mild discomfort, with 2–4 repetitions per stretch (ACSM 2006).
Although there is much more to learn in the field of exercise research and menopause, what we do know supports physical activity as a means to help manage menopausal consequences. During all phases, wellness goals should be to strive for ideal body composition and peak bone mass. Fitness professionals can help support their menopausal clients’ efforts to remain healthy by designing programs that include cardiovascular, strength and flexibility segments that challenge and motivate clients.