2012 Women’s Health Research Review

Scientists are perpetually uncovering new insights that can help exercise professionals improve the health of female (and male) clients. However, navigating one’s way through research reports can be overwhelming—and often contradictory.

To clear up some of the confusion, we have reviewed recent research on six topics central to women’s health. For each issue, we present a key health question and summarize a recent research article that suggests a proper response. Each topic closes with a “take-home message” that offers practical guidance and recommendations for exercise professionals. The topics are

• stroke and physical activity;
• breast cancer prevention;
• metabolic syndrome and occupational physical activity;
• physical activity during pregnancy and postpartum;
• weight gain during menopause; and
• adherence to strength-training programs.

We also include a question-and-answer sidebar on women’s health.

Stroke and Physical Activity

Sattelmair, J.R., et al. 2010. Physical activity and risk of stroke in women. Stroke, 41 (6), 1243–50.

Stroke represents a decrease of blood flow to the brain, depriving it of oxygen and nutrients. A major threat to women and men, stroke is the third-leading cause of disability and death in the United States. Fortunately, exercise can be an effective defense against stroke. According to Sattelmair and colleagues (2010), physical activity reduces the risk of stroke by 25%–30%.

The Sattelmair research team investigated the risk of stroke in 39,315 healthy women who were ≥45 years of age at baseline. Participants were required to report their physical activity during various follow-ups, which occurred at months 36, 72, 96, 125 and 149 of this study.

Sattelmair et al. assessed whether the occurrence of stroke was related to physical activity or other variables such as height, weight, age, diet, history of hypertension, elevated cholesterol levels, diabetes mellitus, use of postmenopausal hormones, occurrence of migraine headaches and parental history of heart attacks. Stroke occurrence was recorded during follow-ups and confirmed through medical records. Additionally, each participant was classified according to body mass index (BMI): healthy weight = BMI < 25 kg/m²; overweight = BMI 25–29.9 kg/m²; or obese = BMI > 30 kg/m².

The assessment of physical activity estimated how long each participant engaged in eight types of activities: walking, jogging, hiking, group-led aerobics, swimming, yoga, stretching and using machines such as stationary bikes and treadmills. The researchers estimated how many kilocalories (kcal) participants burned via exercise every week, and people were divided into quartiles of energy expended: <200, 200–599, 600–1499 or >1500 kcal/week, respectively.

Sattelmair et al. concluded that fast-paced walking on a regular basis significantly reduces the risk of stroke. The most-active women in this study were 17% less likely to have a stroke than the least-active women. The study also found that women who walked 2 or more hours a week at a brisk (somewhat hard) pace had a 30% lower chance of having a stroke.

Take-home message. Encouraging women to do daily physical activity that progressively develops into a brisk (somewhat difficult) intensity yields the greatest protection from stroke.

Breast Cancer Prevention Update

Magné, N., et al. 2011. Recommendations for a lifestyle which could prevent breast cancer and its relapse: Physical activity and dietetic aspects. Critical Reviews in Oncology/Hematology, 80, 450–59.

Breast cancer is a major health risk in women. The two main types of breast cancer are ductile carcinoma (the more common type), which occurs in the ducts that allow the milk to travel from the breast to the nipple; and lobular carcinoma, which occurs in the lobules, where milk is produced. There appears to be a link between breast cancer protection and healthy lifestyle habits such as proper diet and exercise. According to Magné and colleagues (2011), a healthy diet (low in saturated and trans fats and low in simple sugars) and light- to moderate-intensity exercise may aid in the prevention of breast cancer among premenopausal women.

Several studies reviewed by the authors suggested that early intervention by healthy eating and consistent physical activity can be meaningful in breast cancer prevention. In fact, the authors stated that “the link between dietary habits and breast cancer appears potentially very early, between the ages of 3–5 years.” Key et al. (2004) found that overweight and obesity are very related to breast cancer (and other cancers) and suggested patients should strive to attain a healthy BMI (<25 kg/m2). In addition, Magné et al. cited research suggesting that alcohol intake (≥7 alcoholic beverages a week) is associated with increased risk of breast cancer.

The authors explained that dietary and activity lifestyle interventions modify breast cancer risk through their varying effects on hormone metabolism (estrogen, progesterone and IGF receptors). Improving the diet and getting more exercise may also improve the quality of life in postmenopausal women with breast cancer. From the research review, the authors recommended women engage in 3–5 hours of moderate-intensity exercise each week.

Take-home message. Current research confirms that physical activity helps reduce the risk of breast cancer. Unfortunately, a great majority of women are quite sedentary in their daily lives. Two major breast-cancer-prevention goals of personal trainers should be (1) to encourage and educate female clients of all ages to engage in physical activity and (2) to design satisfactory workout programs that complement female clients’ work schedules. Children and teens are no exception to this goal. In fact, Magné et al. (2011) cited research suggesting that the benefits of living a healthy, physically active lifestyle in childhood carry through into adulthood.

Metabolic Syndrome and Occupational Physical Activity

Mozumdar, A., & Liguori, G. 2011. Occupational physical activity and the metabolic syndrome among working women: A Go Red North Dakota study. Journal of Physical Activity & Health, 8, 321–31.

Physical activity plays a major role in the prevention of metabolic syndrome, which is becoming increasingly prevalent in women. To be diagnosed with metabolic syndrome, a woman must have three or more of the following risk factors:

• hypertension (≥130/85 mm Hg or on a blood pressure–lowering medicine)

• high blood triglycerides (≥150 mg/dL)

• high fasting glucose (≥100 mg/dL)

• above-normal waist circumference (>35 inches)

• low HDL cholesterol (≤50 mg/dL)

The study by Mozumdar & Liguori found that occupational physical activity may help decrease the risk of metabolic syndrome in working women. The study included 642 women, aged 35–55, who were asked to complete a survey on lifestyle habits revealing how much of their leisure time was devoted to physical activity. Subjects also participated in a biometric assessment that measured their blood pressure, cholesterol, height, weight, BMI, fasting blood glucose and blood lipids.

The study placed women into three categories. The first was for women who maintained a sedentary occupation, defined as working in a sitting position for an entire day. The second was for women who maintained a moderately active occupation, described as standing and walking during work throughout the day. The third was for women who maintained a “heavy working occupation,” defined as being highly active throughout the working day. The scientists identified whether or not each woman had metabolic syndrome.

Study results indicated that women in moderate to heavy working occupations may actually acquire enough physical activity to ward off metabolic syndrome. Also, the more active the women are during their leisure time, the less likely they are to have metabolic syndrome. By contrast, the least-active women who also have sedentary jobs are the most likely to have metabolic syndrome.

Take-home message. In today’s technological society, most working women’s jobs involve sustained sitting at a desktop computer workstation. Thus, leisure-time physical activity is essential in reducing the risk of metabolic syndrome. Women in highly active occupations face less risk of metabolic syndrome because of the demands of their jobs.

Physical Activity During Pregnancy and Postpartum

Doran, F., & Davis, K. 2011. Factors that influence physical activity for pregnant and postpartum women and implications for primary care. Australian Journal of Primary Health, 17 (1), 79–85.

According to old-school thinking, exercise during pregnancy puts mothers and unborn babies at risk. Many studies, however, have shown that exercise has profound benefits for the mother and the fetus (Doran & Davis 2011). It is highly recommended that women get 30 minutes of moderate-intensity exercise on most, if not all, days before, during and after pregnancy (Doran & Davis). Benefits include weight management, prevention of gestational diabetes mellitus (and thus type 2 diabetes), better physiological readiness for the demands of childbirth, and the energy and ability to properly care for a newborn baby. Alas, in spite of these benefits, most women do not get the recommended amount of exercise.

Doran and Davis sought to determine the factors that prevent pregnant and postpartum women (currently pregnant or who have experienced gestational diabetes within the previous 18 months) from engaging in physical activity. Of the 72 women aged 18–45 who completed the study’s survey, 37 had gestational diabetes mellitus and 34 women were pregnant when they answered the survey. Results confirmed that several factors influence physical activity—positively and negatively—in pregnant and postpartum women. Unfortunately, close to 72% of survey respondents said their healthcare provider had not provided guidance on the benefits of engaging in moderate physical activity, either during or after pregnancy.

Table 1 is a helpful checklist for exercise professionals to use when working with clients during and after pregnancy. It summarizes the barriers to exercise and enabling factors that encourage exercise participation.

Take-home message. Exercise during and after pregnancy may be decisive in the prevention or management of gestational diabetes mellitus and type 2 diabetes as well as other ailments. Exercise professionals have many options for encouraging pregnant and postpartum women to engage in 30 minutes of moderate-intensity exercise on most, if not all, days before, during and after pregnancy.

Weight Gain After Menopause

Al-Zadjali, M., et al. 2010. Evaluation of intervention research in weight reduction in postmenopausal women. Geriatric Nursing, 31 (6), 419–34.

Postmenopausal weight gain is of great concern to exercise professionals working with female clients 50 and older. The prevalence of obesity has increased significantly over the past few decades with a very steep increase in women before, during and after menopause. Cross-sectional examinations of data on overweight populations show higher obesity rates for women during postmenopausal years (Al-Zadjali et al. 2010). Moreover, as women age, overweight and obesity are serious risk factors for heart disease and diabetes.

Al-Zadjali et al. (2010) assessed the pros and cons of weight loss interventions in postmenopausal women. From an exhaustive research evaluation of 120 articles, the research team found 15 that met the strict inclusion criteria.

Overall, the research showed that a dietary intervention of meal replacements, reduced fat intake, reduced saturated fat and cholesterol consumption, and lower daily caloric consumption—when combined with increased physical activity—produces the most health benefits. The combined interventions led to decreases in BMI, fat mass, waist circumference, systolic blood pressure, triglycerides, glucose, leptin and cortisol, triglycerides, glucose and low-density lipoprotein (LDL) cholesterol. Losing weight also reduced plasma C-reactive protein, a strong marker for cardiovascular disease.

The authors reported that weight-bearing exercise produces positive weight loss and maintains or increases bone mineral density in postmenopausal women. The scientists noted that even low-intensity exercise improves cardiorespiratory fitness and reduces body weight in obese postmenopausal women. However, progressively increasing to a moderate-intensity exercise is the eventual goal for optimal management of metabolic risk variables (such as insulin resistance) during and after menopause.

Take-home message. This research review confirms that a combination of varying levels of cardiovascular exercise intensity, weight-bearing exercise (resistance training or cardiorespiratory) and dietary interventions of meal replacement, lower caloric consumption, reduced intake of saturated fat and lower cholesterol leads to the best health and weight management results for postmenopausal women. ACSM recommends 250–300 minutes/week (~2,000 kilocalories/week) of moderate-intensity exercise for greater weight loss and prevention of weight gain (Donnelly et al. 2009).

Strength Training Adherence

Arikawa, A.Y., O’Dougherty, M., & Schmitz, K.H. 2011. Adherence to a strength training intervention in adult women. Journal of Physical Activity & Health, 8 (1), 111–18.

Strength training plays an essential role in maintaining a healthy lifestyle. The evidence is clear that resistance training can enhance musculoskeletal fitness, resulting in prominent health improvements and reduced risk of chronic disease and disability (Warburton, Nicol & Bredin 2006). Longitudinal investigations have revealed that women (and men) with high levels of muscular strength have fewer functional limitations and lower incidences of chronic ailments such as coronary artery disease, diabetes, stroke, arthritis and pulmonary disorders (Warburton, Nicol & Bredin 2006).

Despite the benefits of strength training, many women have trouble adhering to a training routine. According to Arikawa, O’Dougherty & Schmitz (2011), only 17.5% of women engage in a strength training routine 2 or more days per week—the recommended minimum suggested by the American College of Sports Medicine (Garber et al. 2011). Arikawa, O’Dougherty & Schmitz also noted that very little is known about what motivates premenopausal women to stick with resistance training.

The researchers sought to address the adherence question in a 2-year, twice-weekly weight training intervention involving 164 sedentary, overweight and obese premenopausal women (aged 25–44). The intervention included both supervised and unsupervised exercise instruction. For the first 4 months, participants worked out in a program supervised by certified fitness trainers, meeting twice a week for 60–90 minutes per session. The beginning of the regimen included cardiorespiratory exercises and exercises for the abdominals and lower back. Subjects then started their strength training workout, which consisted of three sets of nine exercises performed at 8- to 10-repetition maximum (i.e., the women attained momentary muscular fatigue between 8 and 10 reps).

The next phase of the study (months 5–24) was unsupervised. Subjects continued the workout regimen but on their own or with a friend. During this time, they could decrease their sets to two per exercise. In this unsupervised period, researchers offered “booster sessions” every 12 weeks, where groups of two to six participants met with a personal trainer to learn new exercises and ensure they were performing all exercises correctly. These sessions also provided encouragement to the women. Each subject could schedule an independent booster session once a week with a trainer if she so desired.

The study found that women adhered to the supervised (95.4% adherence) workout program much better than the unsupervised (64.5% adherence) program. Findings also revealed that married women had better adherence (75.4%) than unmarried women (36.35%). However, mothers noted that being a parent was a challenge to scheduling exercise time. Race, age or work status had no notable effect on exercise adherence.

Take-home message. This study objectively demonstrates the value of exercise professionals’ role in educating and motivating female clients to stick with resistance training exercises. This should encourage personal trainers to enhance their business by providing other options for exercise participation, such as small-group training, to involve more women in supervised exercise.