Polar rs800cx heart rate receiver

Data were collected in a room with the temperature set between 21°C and 25°C and relative humidity regulated between 50% and 60%. The volunteers were instructed not to drink alcoholic or caffeinated beverages for 24 hours before the evaluation. The data were collected on an individual basis between 8 AM and 12 PM. The procedures necessary for the data collection were explained on an individual basis; the subjects were instructed to remain at rest and avoid talking during the data collection.
After the initial evaluation, we placed the heart monitor belt over the subject's thorax, aligned with the distal third of the sternum, and the Polar RS800CX heart rate receiver (Polar Electro, Finland) was placed on the wrist. The subjects were seated and remained at rest with spontaneous breathing for 10 minutes with the earphones turned off.
The protocol was performed on the following sequence: 1) Record of 10 minutes with no music exposure; 2) After 10 minutes of rest, the subjects were exposed to excitatory heavy metal (Gamma Ray's "Heavy Metal Universe") or classic baroque (Pachelbel's "Canon in D Major") musical auditory stimulation for 5 minutes each style; 3) subsequently, the individuals remained at rest for 5 minutes and; 4) thereafter they were exposed to musical auditory stimulation for 5 minutes. The sequence of songs was randomized for each individual
[16 (link),17 (link)].

Data were collected in our laboratory under controlled temperature (21°C–25°C) and humidity (50%–60%), and volunteers were instructed to avoid consuming alcohol, caffeine and substances that influence the ANS for 24 hours before evaluation. Data were collected between 8 and 12 AM. All procedures necessary for the data collection were explained to the individuals, and the subjects were instructed to remain at rest and to avoid talking during the data collection.
After the initial evaluation the heart monitor belt was then placed over the thorax, aligned with the distal third of the sternum and the Polar RS800CX heart rate receiver (Polar Electro, Finland) was placed on the wrist. The subject remained 10 minutes seated at rest with spontaneous breathing. After ten minutes the volunteers quickly stood up from a seated position in up to three seconds according to verbal command and remained standing for 15 minutes.