Peak Physiological Responses In Cycling And A New Underwater Swimming Test In Highly Trained Artistic Swimmers

Abstract

PURPOSE: The purpose of this study was to compare peak oxygen uptake (VO2peak) measured in an underwater swim test (UWST) and during a maximal aerobic capacity test on a cycle ergometer (Velotron Pro, Seattle, WA, USA). METHODS: Highly trained artistic swimmers (n=14, 14.9 ± 1.9 yrs) completed a synchronised swimming specific test (275m UWST) in a 25m pool an incremental exercise test to volitional fatigue (15 W every 30 sec to exhaustion) on a cycle ergometer to determine VO2peak. The UWST and maximal aerobic capacity testing occurred on consecutive days. The 275m UWST comprised 50m freestyle followed by 25m underwater breast stroke three times, with an additional 50m freestyle. During the UWST participants wore water-resistant HR monitors (Polar OH1) and had expired gases collected (Cosmed K4 b2) in the 20 sec immediately upon completion of the UWST to determine VO2peak. During the cycle test, HR (Polar Electro, Kempele, Finland) and expired gases were collected using a MOXUS metabolic cart (AEI Technologies, Pittsburgh, PA, USA). Peak physical work capacity (PWC) (W) was measured as the highest completed 30 sec stage of the test. RESULTS: VO2peak achieved after the UWST (44.3 ± 8.0 mL/kg/min) and cycle ergometer (42.3 ± 7.2 mL/kg/min) did not differ significantly from each other (t=-0.59, df=13, p=0.563, d=0.21). HRpeak was significantly lower during the UWST (162.5 ± 18.4 bpm) (t=7.812, df=12, p<0.00, d=2.10) when compared to the cycle test (194.6 ± 11.6 bpm) . The UWST time and PWC during the bike test were not significantly correlated to each other (r=-0.25, p=0.393). There was no significant correlation between the VO2peak achieved during the UWST and the duration of the UWST (r=-0.39, p=0.17). HRpeak during the UWST was significantly correlated with the VO2peak (r=0.62 p=0.03 CI95 [38.93, 46.44]) and HRpeak achieved on the cycle ergometer (r=0.59, p=0.04 CI95 [188.79, 200.92]). CONCLUSIONS: The similarities in VO2 data during the UWST and VO2peak protocol suggest the UWST is a valid method of determining VO2peak in highly trained artistic swimmers. A goal when selecting a VO2 protocol is to mimic the demands of the sport. In this population, the UWST is likely better than the cycle ergometer, as the modality of swimming with breath holding more closely matches the demands of an artistic swim routine.