The purpose of this study was to determine whether branched-chain amino acid (BCAA) supplementation attenuates indirect indicators of muscle damage during endurance exercise as compared with an isocaloric, carbohydrate (CHO) beverage or a noncaloric placebo (PLAC) beverage. Nine untrained men performed three 90 min cycling bouts at 55% VO 2peak. Subjects, blinded to beverage selection, ingested a total of 200 kcal of energy via the CHO or BCAA beverage before and at 60 min of exercise, or they drank the PLAC beverage. Creatine kinase (CK), lactate dehydrogenase (LDH), isokinetic leg-extension and -flexion torque, and muscle soreness were assessed before and immediately, 4 h, 24 h, and 48 h postexercise. The trials were separated by 8 wk. CK activities were significantly lower after the BCAA trial than in the PLAC trial at 4, 24, and 48 h postexercise, as well as lower than the CHO beverage at 24 h postexercise. CK was lower in the CHO trial at the 24- and 48-h time points than in the PLAC trial. LDH activities were lower in the BCAA trial at 4 h than in the PLAC trial. As compared with the CHO and PLAC trials, ratings of perceived soreness were lower at 24 h postexercise, and leg-flexion torque was higher at the 48-h time point after the BCAA trial. The present data suggest that BCAA supplementation attenuates muscle damage during prolonged endurance exercise in untrained college-age men. CHO ingestion attenuates CK activities at 24 and 48 h postexercise as compared with a placebo beverage.

PurposeTo determine if timing of a supplement would have an effect on muscle damage, function and soreness.MethodsTwenty-seven untrained men (21 ± 3 yrs) were given a supplement before or after exercise. Subjects were randomly assigned to a pre exercise (n = 9), received carbohydrate/protein drink before exercise and placebo after, a post exercise (n = 9), received placebo before exercise and carbohydrate/protein drink after, or a control group (n = 9), received placebo before and after exercise. Subjects performed 50 eccentric quadriceps contractions on an isokinetic dynamometer. Tests for creatine kinase (CK), maximal voluntary contraction (MVC) and muscle soreness were recorded before exercise and at six, 24, 48, 72, and 96 h post exercise. Repeated measures ANOVA were used to analyze data.ResultsThere were no group by time interactions however, CK significantly increased for all groups when compared to pre exercise (101 ± 43 U/L) reaching a peak at 48 h (661 ± 1178 U/L). MVC was significantly reduced at 24 h by 31.4 ± 14.0%. Muscle soreness was also significantly increased from pre exercise peaking at 48 h.ConclusionEccentric exercise caused significant muscle damage, loss of strength, and soreness; however timing of ingestion of carbohydrate/protein supplement had no effect.

The findings highlight the importance of reducing sedentary behavior, increasing physical activity, and improving cardiorespiratory fitness for preventing metabolic syndrome.

Using a semistructured discussion guide, the authors conducted 15 interviews with physically active older Black women living in the eastern U.S. to examine what contributed to their physical activity initiation and maintenance. They used thematic analysis to organize content and constant-comparison methods to compare themes between participants. Participants initiated physical activity when a cue to action, such as weight gain or a medical issue, triggered a perceived need to exercise. When participants initiated physical activity, they experienced immediate unexpected benefits such as improved energy. They reported continuing activity because of these initial benefits. After continued physical activity over time, participants experienced the health benefits they originally hoped to achieve. Most participants also mentioned continuing physical activity because it is “me time.” All participants reported needing to modify their physical activity routine at some point. Having a regular, yet adaptable, routine and planning skills helped participants maintain physical activity. These findings contribute to the refinement of theory and might be useful for professionals promoting physical activity among older Black women.

Both RT and IT aerobic work increased EPOC to a greater degree than did SS work, indicating that either mode may be more effective at increasing total daily caloric expenditure than SS aerobic exercise.