Cardiorespiratory Responses to Exercise in Elderly

The CPET was performed in a cycle ergometer with electromagnetic braking using an Inbrasport (Inbrasport, Porto Alegre, Rio Grande do Sul, Brazil). Following a 5-min warm-up against no resistance (0 W), the work rate was increased using a ramp protocol (5-10 W.min-1) until maximum exercise tolerance. Verbal encouragements were given during the CPET to ensure maximal effort.

The polysomnography assessment was carried out during an entire night of sleep in the participant's residence with no use of sedatives. The variables were monitored by an Embletta portable respiratory monitor (Embla, Embletta® Gold, EUA), previously validated, and in agreement with manufacturer's instructions. The Embletta monitor was capable to monitor continuously the pulse oximetry, to detect respiratory efforts, to measure the airflow, and to record snoring episodes. Additionally, HR was continually measured by the analysis of pulse waves by oximetry. Finally, brain and muscle activities were monitored by electrodes and oxygen desaturation (O2D) was defined as the amount of reduction in O2S in 4%/h.