The Absolute and Relative Reliability of Psychophysiological Responses to Self-Selected Exercise Intensity in Elderly Women.

Background: Self-selected exercise intensity (SSEI) promotes higher affect (pleasure) during exercise, but its reliability is still unclear. Purpose: to evaluate the test-retest reliability and the minimum detectable change of the perceptive and physiological responses in two sessions of SSEI on treadmill in elderly women. Method: Twenty elderly women (ages 65.3 ± 4.2 years) performed two 20-min laboratory-based treadmill aerobic exercise sessions with self-selected intensity. During the sessions, %VO2max, %HRreserve, affect, and rating of perceived exertion (RPE) were recorded. Reliability was calculated using the intraclass correction coefficient (ICC) and Bland-Altman plots. The minimum detectable change (MDC) was also calculated. Results: ICC values were 0.98 for % VO2max, 0.83 for % HRreserve, 0.85 for affect, and 0.80 for RPE. No differences were observed in mean values between sessions for all the variables. MDCs were lower than 0.7% for VO2max, 11.7% for HRreserve, 0.7 for affect, and 0.8 for RPE. Bland-Altman plots showed a bias of 0.50% for HRreserve, 3.2% for VO2max, 0.05 for affect, and -0.35 for RPE. Conclusion: Self-selected intensity during aerobic exercise performed on treadmill is reliable, which promotes adequate and lower MDC values on physiological and perceptual responses in elderly women.

Oxygen uptake and heart rate kinetics after different types of resistance exercise.

Oxygen uptake (VO2) and heart rate (HR) kinetics after exercise are important indicators of fitness and cardiovascular health. However, these variables have been little investigated in resistance exercise (RE). The current study compared post-exercise kinetics of VO2 and the HR among different types of REs. The study included 14 males (age: 26.5±5.4 years, body mass: 80.1±11.4 kg, body height: 1.77±0.07 m, fat content: 11.3±4.6%) with RE experience. Dynamic muscle strength was measured using one repetition maximum (1RM) with regard to the half-squat, bench press, pull-down, and triceps pushdown exercises. The participants performed a maximum number of repetitions at 80% of 1RM for each exercise, separated by a recovery period of 60 minutes. VO2 was measured using ergospirometry. VO2 and HR kinetics were assessed using the time constant of the recovery curves, and excess oxygen consumption (EPOC) was calculated afterward. Significant differences were not observed across the exercises with regard to VO2 kinetics. However, the half-squat exercise elicited a greater EPOC than the bench press and triceps pushdown exercises (p<.05). HR kinetics was slower for the half-squat exercise than for the other exercises (p<.05). These findings confirm that the type of RE influences both the cardiac autonomic response post-exercise and EPOC, but not VO2 kinetics.

Association between different phases of menstrual cycle and body image measures of perceived size, ideal size, and body dissatisfaction.

The association between phases of the menstrual cycle and body image was investigated. 44 university women (M age = 23.3 yr., SD = 4.7) judged their perceived and ideal body size, and body dissatisfaction was calculated at each phase of the menstrual cycle, including premenstrual, menstrual, and intermenstrual. Participants selected one of nine figural drawings ranging from very thin to obese that represented their perceived size and ideal size. Body dissatisfaction was measured as the absolute difference between scores on perceived and ideal figural drawings. During each menstrual phase, anthropometric measures of weight, height, body mass index, circumference of waist and abdomen, and body composition were taken. There were no significant differences in any anthropometric measures between the three menstrual cycle phases. Perceived body size and body dissatisfaction were significantly different between menstrual phases, with the largest perceived body size and highest body dissatisfaction occurring during the menstrual phase. Ideal body size did not differ between menstrual phases, although participants desired a significantly smaller ideal size as compared to the perceived size.