The question used to assess location of exercise had the following response options: home, outdoor in nearby area, nature, gym, indoor- and outdoor sports facility. Indoor- and outdoor sports facility was categorized as “sports facility” due to a low response rate on the outdoor sports facility option (1%). For social setting of exercise, the response options were: exercised alone, exercised together with others, and organized by Generation 100.
Physiological, psychological and EMG responses to the time to exhaustion tests are presented Figs 4 and 5. Leg RPE (Fig 4A), leg muscle pain (Fig 4B) and heart rate (HR, Fig 4C) increased over time (all P < 0.001). Cadence during the time to exhaustion decreased over time (P < 0.001). Planned comparisons for these aforementioned parameters are presented Fig 5. EMG RMS of the VL (Fig 5A), VM (Fig 5B), RF (Fig 5C) and the sum of these muscles (Fig 5D) increased over time (all P < 0.001). Planned comparisons for EMG parameters are presented Fig 5. Blood lactate concentration increased (from 1.3 ± 0.5 to 6.0 ± 1.1 mmol/L, P < 0.001) and blood glucose concentration decreased (from 5.3 ± 0.5 to 4.4 ± 0.3 mmol/L, P = 0.001) over time.
Limitation of the Study. One potential limit of the present study undoubtedly regards the limited number of subjects involved in the study and the operating loss of the control group. Unfortunately, too many participants of the latter did not satisfy the requirements during the study, thus impeding a comparative statistical approach. Further studies are therefore needed to confirm our conclusions, in particular with a larger sample and control group.
Samples were collected in prefrozen 4.5 ml K3 EDTA vacutainer tubes (Becton Dickinson Vacutainer System Europe, Plymouth, UK) and immediately centrifuged at 3000 rpm (Minifuge 2, Heraeus, Germany) for 10 min, and plasma was frozen at −20°C until further analysis. Samples were assayed via RIA for cortisol (DiaSorin, Stillwater, Minnesota, USA), ACTH (Nichols Institute Diagnostics, San Juan Capistrano, California, USA), PRL (Roche Diagnostics, Mannheim, Germany) and GH (Pharmacia & Upjohn Diagnostics, Uppsala, Sweden).
Recruiting lasted 6 months starting from September 2013. Participants were recruited by means of family doctors to whom the goal of the study was explained. The recruitment flow chart is shown in Figure 1. Three hundred and fifty people aged ≥ 65 were invited to participate. Of these, 51.4% agreed to be included in the screening list while 48.6% refused to participate, mainly for family reasons such as illness/hospitalization/old age of a family member. Forty people were found eligible to participate in the research protocol. Randomly, twenty were assigned to VE and twenty to the control group. The latter were instructed not to take part in any physical activity throughout the study period. All the selected participants signed an informed consent. The study was performed according to the Declaration of Helsinki and approved by the local ethics committee on September 23, 2013.