The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women

This study assessed the influence of estrogen (E 2 ) on muscle damage biomarkers [skeletal muscle - creatine kinase (CK); cardiac muscle - CK-MB] responses to prolonged aerobic exercise. Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at ~60-65% maximal intensity during low E 2 (midfollicular menstrual phase) and high E 2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise (following supine rest), immediately post-, 30 min post-, and 24 hours post-exercise to determine changes in muscle biomarkers. Resting blood samples confirmed appropriate E 2 hormonal levels Total CK concentrations increased following exercise and at 24 hours post-exercise were higher in the midfollicular low E 2 phase (p<0.001). However, CK-MB concentrations were unaffected by E 2 level or exercise (p=0.442) resulting in the ratio of CK-MB to total CK being consistently low in subject responses (i.e., indicative of skeletal muscle damage). Elevated E 2 levels reduce the CK responses of skeletal muscle, but had no effect on CK-MB responses following prolonged aerobic exercise. These findings support earlier work showing elevated E 2 is protective of skeletal muscle from exercise-induced damage associated with prolonged aerobic exercise

Insights Following Implementation of an Exercise Intervention in Older Veterans with PTSD

Individuals with post-traumatic stress disorder (PTSD) face numerous barriers to exercise. Little is known about behavioral strategies to promote participation in this population. This is a secondary analysis of individual barriers and goals, exercise prescription characteristics, and patient perceptions of a 12-week, community-based, randomized controlled exercise trial targeting older adults with PTSD, (N = 45; mean age = 68; male = 91%). The most common cited goals for participating included weight loss (65%) and increasing strength (65%). Exercise mode varied among those who completed the program (n = 37), with 14 (38%) using exclusively treadmill; eight (22%) using only bike, and 15 (41%) utilizing a combination. Patient-reported exercise duration and intensity progressively increased over the 12 weeks, and duration differed by mode of exercise. We observed high rates of attendance (84%) and completion (88%) to the program. Patient-reported barriers to attendance most often included health problems (62%) and medical appointments (55%). Participant responses to a program evaluation revealed high levels of satisfaction, preferences for group-based programs, and insights about the acceptability of the exercise environment (physical and social). This study is the first to report on goals, barriers, exercise prescription needs, and individual responses to supervised exercise training in a unique population, that is, older veterans with PTSD. Results of this study can inform future health promotion programs targeting older veterans with PTSD

The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women

This study assessed the influence of estrogen (E 2 ) on muscle damage biomarkers [skeletal muscle - creatine kinase (CK); cardiac muscle - CK-MB] responses to prolonged aerobic exercise. Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at ~60-65% maximal intensity during low E 2 (midfollicular menstrual phase) and high E 2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise (following supine rest), immediately post-, 30 min post-, and 24 hours post-exercise to determine changes in muscle biomarkers. Resting blood samples confirmed appropriate E 2 hormonal levels Total CK concentrations increased following exercise and at 24 hours post-exercise were higher in the midfollicular low E 2 phase (p<0.001). However, CK-MB concentrations were unaffected by E 2 level or exercise (p=0.442) resulting in the ratio of CK-MB to total CK being consistently low in subject responses (i.e., indicative of skeletal muscle damage). Elevated E 2 levels reduce the CK responses of skeletal muscle, but had no effect on CK-MB responses following prolonged aerobic exercise. These findings support earlier work showing elevated E 2 is protective of skeletal muscle from exercise-induced damage associated with prolonged aerobic exercise