# Impact of Music Selection on Motivation and Performance during Cardiopulmonary Exercise Testing
## 2 Materials and Methods
### Procedure  
The study was approved by the Ethical Committee of the University of Belgrade--Faculty of Sport and Physical Education (approval number 02-1986/21-2). All procedures were conducted following the standards established by the Declaration of Helsinki and its later amendments. The study was conducted in three phases from June to August 2021. In Phase I, the participants performed an initial CPET according to the ramp protocol with a constant increase in load until reaching the peak respiratory exchange ratio (peak RER) \(\geq\) 1.1 and peak heart rate (peak HR) at a value \(\geq\) 90% of the theoretical maximum HR, according to current guidelines [33; 34]. Participants were advised not to exercise at least 48 h before the test and to eat only a light breakfast and not to consume caffeine at least 2 h before testing. CPET was performed in the morning under controlled conditions (temperature and humidity in the room) for all subjects. Test was performed on an h.p. Cosmos treadmill, while gas analysis was measured using the \"breath by breath\" method on a Cardiovit CS 200 ergospirometer ([PERSON], Baar, Switzerland) and printed at 10 s intervals. Before the first testing, echocardiography was performed, while spirometric tests were performed before the start of both CPET. Numerous cardiopulmonary variables were measured by testing, and among the most important were peak VO2 and VO2 at VT2. VO2 max represented the mean of peak VO2 (mL/kg/min) and was calculated using the highest VO2 measurement average in 30 s [35]. The VT2 was determined, using the ventilation/carbon dioxide production (VE/VCO2) plot at the point where VE increases out of proportion to the VCO2 [10]. During the CPET, the [PERSON]'s Rating of Perceived Exertion (RPE) Scale6-20 was used to assess the level of perceived exertion [36; 37]. Before the test, the subjects were familiarized with the [PERSON]'s scale. The verbal descriptions of the numbers (from 6 to 20) on the exertion scale were translated from English to Serbian by a certified expert. Before the test, during the test (in the second half of every even minute), and at the end of the test, the subject indicated with his index finger on a large board (held near the subject by one of the researchers), the number that best corresponds to the current subjective feeling of exertion. After that, the researcher would repeat out loud the number that the subject showed, the subject would nod his head affirmatively, and only then would that number be entered into the corresponding field in relation to the elapsed time of the test. Later, gas analysis determined when the subject reached the VT2 and what was her subjective assessment of effort at that intensity. A short interview was conducted with each subject after the test, with questions regarding their overall impression of the test. The main purpose of the interview was for the researchers to make sure that everything was fine with the subject after the test. In Phase II, an interview was conducted with the participants regarding their favorite music, including questions such as (1) what type of music they like to listen to, (2) which music genre they prefer, and (3) who their favorite band/artist is, and then they were asked to send several faster tempo songs that they would like to listen to while walking on the treadmill, meaning songs that would make them want to exercise longer and harder. Based on the responses, a list of music tracks was created specifically for each participant, where each track had to have a tempo > 120 beats per minute (120 bpm). Afterwards, all participants were asked to complete the BMRI-2 questionnaire for each song from their list. The BMRI-2 questionnaire, constructed by [PERSON] et al. (2014), was used to examine the motivational qualities of music. For the purposes of this study, the BMRI-2 questionnaire was translated and adapted to the musical terminology in the Serbian language.