After signing the consent form, the participants were asked to complete a VO2max test in order to assess their level of cardiorespiratory fitness.
True One 2400 metabolic cart (ParvoMedics, Sandy, UT) was used for analyzing expired gases, and a Polar chest strap was used to monitor heart rate (HR; Polar Electro Oy, Finland). The metabolic system was calibrated before each use with a 3L syringe. After a five minute warm-up at a self-selected pace, a Modified Astrand-Saltin VO2max protocol was implemented (21 (link)). For this protocol, a speed slightly higher than each participant’s normal training speed was chosen, and was clamped for the entirety of the test. The grade, initially at 0%, was increased by 2% every two minutes until volitional exhaustion. The two highest consecutive values for relative O2 consumption were averaged for determination of VO2max. Tests were considered to be maximal if two of the following three criteria were obtained: (1) RPE: ≥18; (2) HR: within 10 bpm of the participant’s age predicted maximal HR (where HRmax = 220 – age); (3) VO2 plateau: difference between peak relative VO2 value and the value in the preceding 15 seconds of 2.0 ml·kg−1·min−1 or less.
True One 2400 metabolic cart (ParvoMedics, Sandy, UT) was used for analyzing expired gases, and a Polar chest strap was used to monitor heart rate (HR; Polar Electro Oy, Finland). The metabolic system was calibrated before each use with a 3L syringe. After a five minute warm-up at a self-selected pace, a Modified Astrand-Saltin VO2max protocol was implemented (21 (link)). For this protocol, a speed slightly higher than each participant’s normal training speed was chosen, and was clamped for the entirety of the test. The grade, initially at 0%, was increased by 2% every two minutes until volitional exhaustion. The two highest consecutive values for relative O2 consumption were averaged for determination of VO2max. Tests were considered to be maximal if two of the following three criteria were obtained: (1) RPE: ≥18; (2) HR: within 10 bpm of the participant’s age predicted maximal HR (where HRmax = 220 – age); (3) VO2 plateau: difference between peak relative VO2 value and the value in the preceding 15 seconds of 2.0 ml·kg−1·min−1 or less.