title: Peak oxygen uptake during arm stroke under a hypobaric hypoxic condition.
abstract: The purpose of this study was to examine the limiting factor for swimming by measuring peak oxygen uptake (peak VO2) during front crawl (C) and arm stroke (A) under a hypobaric hypoxic condition. Seven-trained swimmers (age; 19-21 yrs, 100 m free style event; 57.2 +/- 2.5 secs) were measured twice under a normal (N) (751 mmHg) and a hypobaric hypoxic (H) (602 mmHg) condition in a chamber where atmospheric pressure was regulated. Water flow rate started at 0.80 m.sec-1 and was increased by 0.05 m.sec-1 every 2 min up to 1.00 m.sec-1. Subsequently, flow rate was increased by 0.05 m.sec-1 every minute until exhaustion. VO2 was measured with an automatic analyzer. The peak heart rate under N was not significantly different from that under H in both C (N; 190 +/- 9, H; 184 +/- 6 beats.min-1) and A (N; 180 +/- 6, H; 181 +/- 6 beats.min-1). Peak VO2 values during A (N; 3.42 +/- 0.27, H; 3.08 +/- 0.19 l.min-1) were significantly lower by 15-20% than those during C (N; 4.18 +/- 0.18, H; 3.65 +/- 0.11 l.min-1) for both N and H (p less than 0.01). Peak VO2 values under H were significantly lower than those under N during both C and A (p less than 0.01). There was no significant difference in the magnitude of decrease in peak VO2 between C (12.0 +/- 3.4%) and A (9.8 +/- 3.8%) under H. This ratio of decrease agrees with previous investigations that studied centrally limited exercise, such as running and cycling, under similar levels of hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Research Institute of Physical Fitness, Japan Women's College of Physical Education.
authors.forename: F
authors.initials: F
authors.lastname: Ogita
authors.forename: I
authors.initials: I
authors.lastname: Tabata
mesh_terms: D000328:Adult; D001273:Atmosphere Exposure Chambers; D001274:Atmospheric Pressure; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D013550:Swimming