Patterning of physiological and affective responses in older active adults during a maximal graded exercise test and self-selected exercise.

PURPOSE: The American College of Sports Medicine has highlighted the importance of considering the physiological and affective responses to exercise when setting exercise intensity. Here, we examined the relationship between exercise intensity and physiological and affective responses in active older adults. METHOD: Eighteen participants (60-74 years; 64.4 ± 3.9; 8 women) completed a maximal graded exercise test (GXT) on a treadmill. Since time to exhaustion in the GXT differed between participants, heart rate (HR), oxygen consumption (VO2), affective valence (affect) and rating of perceived exertion (RPE) were expressed relative to the individually determined ventilatory threshold (%atVT). RESULT: During the GXT, VO2, HR and RPE increased linearly (all P < 0.01). Affect declined initially (but remained positive) (P = 0.03), stabilised around VT (still positive) (P > 0.05) and became negative towards the end of the test (P < 0.01). In a subsequent session, participants completed a 20-min bout of self-selected exercise (at a preferred intensity). Initially, participants chose to exercise below VT (88.2 ± 17.4 %VO2atVT); however, the intensity was adjusted to work at, or above VT (107.7 ± 19.9 %VO2atVT) after 10 min (P < 0.001), whilst affect remained positive. CONCLUSION: Together, these findings indicate that exercise around VT, whether administered during an exercise test, or self-selected by the participant, is likely to result in positive affective responses in older adults.

A perceptually-regulated exercise test predicts peak oxygen uptake in older active adults.

Peak oxygen uptake (VO2peak) is reliably predicted in young and middle-aged adults using a submaximal perceptually-regulated exercise test (PRET). It is unknown whether older adults can use a PRET to accurately predict VO2peak. In this study, the validity of a treadmill-based PRET to predict VO2peak was assessed in 24 participants (65.2 ± 3.9 years, 11 males). The PRET required a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13, and 15. Extrapolation of submaximal VO2 from the PRET to RPE endpoints 19 and 20 and age-predicted HRmax were compared with measured VO2peak. The VO2 extrapolated to both RPE19 and 20 over-predicted VO2peak (p < .001). However, extrapolating VO2 to age-predicted HRmax accurately predicted VO2peak (r = .84). Results indicate older adults can use a PRET to predict VO2peak by extrapolating VO2 from submaximal intensities to an age-predicted HRmax.