Hormone therapy (HT) is a potential treatment to relieve symptoms of menopause and prevent the onset of disease such as osteoporosis in postmenopausal women. We evaluated changes in markers of exercise-induced skeletal muscle damage and inflammation [serum creatine kinase (CK), serum lactate dehydrogenase (LDH), and skeletal muscle mRNA expression of IL-6, IL-8, IL-15, and TNF-α] in postmenopausal women after a high-intensity resistance exercise bout. Fourteen postmenopausal women were divided into two groups: women not using HT (control; n = 6, 59 ± 4 yr, 63 ± 17 kg) and women using traditional HT (HT; n = 8, 59 ± 4 yr, 89 ± 24 kg). Both groups performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on the Cybex dynamometer at 60°/s with 20-s rest periods between sets. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. Gene expression was determined by RT-PCR for IL-6, IL-8, IL-15, and TNF-α. Blood draws were performed at baseline and 3 days after exercise to measure CK and LDH. Independent t-tests were performed to test group differences (control vs. HT). A probability level of P ≤ 0.05 was used to determine statistical significance. We observed significantly greater changes in mRNA expression of IL-6, IL-8, IL-15, and TNF-α (P ≤ 0.01) in the control group compared with the HT group after the exercise bout. CK and LDH levels were significantly greater after exercise (P ≤ 0.01) in the control group. Postmenopausal women not using HT experienced greater muscle damage after maximal eccentric exercise, indicating a possible protective effect of HT against exercise-induced skeletal muscle damage.

CrossFit^® began as another exercise program to improve physical fitness and has rapidly grown into the “sport of fitness”. However, little is understood as to the physiological indicators that determine CrossFit^® sport performance. The purpose of this study was to determine which physiological performance measure was the greatest indicator of CrossFit^® workout performance. Male (n = 12) and female (n = 5) participants successfully completed a treadmill graded exercise test to measure maximal oxygen uptake (VO_2max), a 3-minute all-out running test (3MT) to determine critical speed (CS) and the finite capacity for running speeds above CS (D′), a Wingate anaerobic test (WAnT) to assess anaerobic peak and mean power, the CrossFit^® total to measure total body strength, as well as the CrossFit^® benchmark workouts: Fran, Grace, and Nancy. It was hypothesized that CS and total body strength would be the greatest indicators of CrossFit^® performance. Pearson’s r correlations were used to determine the relationship of benchmark performance data and the physiological performance measures. For each benchmark-dependent variable, a stepwise linear regression was created using significant correlative data. For the workout Fran, back squat strength explained 42% of the variance. VO_2max explained 68% of the variance for the workout Nancy. Lastly, anaerobic peak power explained 57% of the variance for performance on the CrossFit^® total. In conclusion, results demonstrated select physiological performance variables may be used to predict CrossFit^® workout performance.

Hormone replacement therapy (HRT) is used in postmenopausal women to relieve symptoms of menopause and prevent osteoporosis. We sought to evaluate changes in mRNA expression of key myogenic factors in postmenopausal women taking and not taking HRT following a high-intensity eccentric resistance exercise. Fourteen postmenopausal women were studied and included 6 control women not using HRT (59 ± 4 years, 63 ± 17 kg) and 8 women using traditional HRT (59 ± 4 yr, 89 ± 24 kg). Both groups performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on a Cybex dynamometer at 60°/s. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. Gene expression was determined using RT-PCR for follistatin, forkhead box 3A (FOXO3A), muscle atrophy F-box (MAFbx), muscle ring finger-1 (MuRF-1), myogenic differentiation factor (MyoD), myogenin, myostatin, myogenic factor 5 (Myf5), and muscle regulatory factor 4 (MRF4). At rest, the HRT group expressed higher levels of MyoD, myogenin, Myf5, MRF4, and follistatin (P < 0.05). In response to eccentric exercise, follistatin, MyoD, myogenin, Myf5, and MRF4 were significantly increased (P ≤ 0.05) and FOXO3A, MAFbx, MuRF-1, and myostatin were significantly decreased in the control and HRT groups (P ≤ 0.05). Significantly greater changes in mRNA expression of follistatin, FOXO3A, MAFbx, MuRF-1, MyoD, myogenin, myostatin, Myf5, and MRF4 (p≤0.05) occurred in the HRT group than in the control group after exercise. These data suggest that postmenopausal women using HRT express higher myogenic regulatory factor gene expression, which may reflect an attempt to preserve muscle mass. Furthermore, postmenopausal women using HRT experienced a greater myogenic response to maximal eccentric exercise.

Metabolic syndrome (MetS) is increasingly present in breast cancer survivors, possibly worsened by cancer-related treatments, such as chemotherapy. MetS greatly increases risk of cardiovascular disease and diabetes, co-morbidities that could impair the survivorship experience, and possibly lead to cancer recurrence. Exercise has been shown to positively influence quality of life (QOL), physical function, muscular strength and endurance, reduce fatigue, and improve emotional well-being; however, the impact on MetS components (visceral adiposity, hyperglycemia, low serum high-density lipoprotein cholesterol, hypertriglyceridemia, and hypertension) remains largely unknown. In this trial, we aim to assess the effects of combined (aerobic and resistance) exercise on components of MetS, as well as on physical fitness and QOL, in breast cancer survivors soon after completing cancer-related treatments.

Background. Maximal voluntary muscle strength (MVMS) and leg power are important measures of physical function in older adults. We hypothesized that performing these measures twice within 7–10 days would demonstrate a >5% increase due to learning and familiarization of the testing procedures. Methods. Data were collected from three studies in older adult men (60–87 years) and were divided into two cohorts defined by study site and type of exercise equipment. MVMS was assessed in 116 participants using the one-repetition maximum method at two separate study visits for the chest press, latissimus pull-down, leg press, leg flexion, and leg extension exercises along with unilateral leg extension power. Results. Test–retest scores were not different and did not exceed 0.8 ± 9.0% in Cohort 1 or 2.3 ± 9.8% in Cohort 2, except for leg extension, which improved by 6.6 ± 14.4% (p <.009) and 3.4 ± 6.8% (p <.016), respectively. Repeat tests were closely correlated with initial tests (all p <.001). Pearson correlation coefficients ranged from 0.74 for leg extension power to 0.96 for leg press. Coefficients of variation were <10% (4.2%–9.0%) for all exercises except for leg extension power, which was 15.5%. Conclusions. Our findings demonstrated that test–retest measures of MVMS and power in older adult men do not differ by more than 2.3% except for leg extension, and have relatively low coefficients of variation using data collected from three studies. Moreover, these findings were similar between two study sites using different equipment, which further supports the reliability of MVMS and power testing in older adult men.