COMPARISON OF ...O2PEAK PERFORMANCE ON A MOTORIZED VS. A NONMOTORIZED TREADMILL.

Despite growing popularity of nonmotorized treadmills (NMTs), little data exist regarding responses during exercise testing using this equipment, which is important when providing an appropriate exercise prescription. The purpose of this study was to evaluate physiological and perceptual responses during peak graded exercise tests (GXTs) on a motorized treadmill (MT) vs. NMT. Volunteers (12 men and 12 women aged 18-35 years) performed 2 peak GXT sessions (1 MT and 1 NMT). Respiratory gases and heart rate (HR) were collected each minute; perceptual response was estimated (Borg's 6-20 rating of perceived exertion [RPE] scale) during the final 10 seconds of each stage. Peak values (i.e., ...o2, HR, speed) were determined during the final 10 seconds of each test; ventilatory threshold (VT) was assessed using the V-slope method. Paired t-tests matching variables measured at each stage of the GXT identified significantly higher values on the NMT for ...o2 83% of the time, HR 67% of the time, and RPE 25% of the time. Interestingly though, neither peak ...o2 (48.6 ± 9.2 ml·kg·min-1 vs. 47.8 ± 8.9 ml·kg·min-1), peak HR (185 ± 9 b·min-1 vs. 188 ± 10 b·min-1; p = 0.90), nor VT (72.7 ± 5.7% vs. 73.8 ± 5.4%) were significantly different on the NMT vs. the MT. However, significant differences were identified between NMT and MT tests for time to exhaustion (9:55 ± 1:49 vs. 12:05 ± 2:48; p < 0.01) and peak speed (8.0 ± 0.9 mph vs. 9.2 ± 1.4 mph; p < 0.01). Thus, although peak values obtained were similar between testing sessions on the NMT and MT, the majority of submaximal data were significantly different between trials. These differences are important when designing exercise prescriptions using submaximal values from NMT testing that may be inappropriately high or low at corresponding intensities during training. [ABSTRACT FROM AUTHOR]