How much will older adults exercise? A feasibility study of aerobic training combined with resistance training

Both aerobic training (AT) and resistance training (RT) have multidimensional health benefits for older adults including increased life expectancy and decreased risk of chronic diseases. However, the volume (i.e., frequency*time) of AT combined with RT in which untrained older adults can feasibly and safely participate remains unclear. Thus, our primary objective was to investigate the feasibility and safety of a high-volume exercise program consisting of twice weekly AT combined with twice weekly RT (i.e., four times weekly exercise) on a group of untrained older adults. In addition, we investigated the effects of the program on physical function, aerobic capacity, muscular strength, and explored factors related to participant adherence.

We recruited eight inactive older adults (65+ years) to participate in a 6-week, single-group pre-post exercise intervention, consisting of 2 days/week of AT plus 2 days/week of progressive RT for 6 weeks. We recorded program attendance and monitored for adverse events during the course of the program. Participants were tested at both baseline and follow-up on the following: (1) physical function (i.e., timed-up-and-go test (TUG) and short physical performance battery (SPPB)), (2) aerobic capacity (VO₂max) using the modified Bruce protocol; and (3) muscular strength on the leg press and lat pull-down. Post intervention, we performed qualitative semi-structured interviews of all participants regarding their experiences in the exercise program. We used these responses to examine themes that may affect continued program adherence to a high-volume exercise program.

We recorded an average attendance rate of 83.3% with the lowest attendance for one session being five out of eight participants; no significant adverse events occurred. Significant improvements were observed for SPPB score (1.6; 95% CI: [0.3, 2.9]), VO₂max (8.8 ml/kg/min; 95% CI: [2.8, 14.8]), and lat pull-down strength (11.8 lbs; 95% CI: [3.3, 20.2]). Qualitative results revealed two themes that promote older adults' adherence: (1) convenience of the program and (2) the social benefits of exercise.

Our findings suggest untrained older adults can be successful at completing twice weekly AT combined with twice weekly progressive RT; however, these exercise programs should be group-based in order to maintain high adherence.