title: Comparison of muscle buffer capacity and repeated-sprint ability of untrained, endurance-trained and team-sport athletes.
abstract: We measured the muscle buffer capacity (betam) and repeated-sprint ability (RSA) of young females, who were either team-sport athletes (n = 7), endurance trained (n = 6) or untrained but physically active (n = 8). All subjects performed a graded exercise test to determine VO(2peak) followed 2 days later by a cycle test of RSA (5 x 6 s, every 30 s). Resting muscle samples (Vastus lateralis) were taken to determine betam. The team-sport group had a significantly higher betam than either the endurance-trained or the untrained groups (181+/- 27 vs. 148 +/- 11 vs. 122 +/- 32 micromol H(+) g dm(-1) pH(-1) respectively; P < 0.05). The team-sport group also completed significantly more relative total work (299 +/- 27 vs. 263 +/- 31 vs. 223 +/- 21 J kg(-1), respectively; P < 0.05) and absolute total work (18.2 +/- 1.6 vs. 14.6 +/- 2.4 vs. 13.0 +/- 1.9 kJ, respectively; P < 0.05) than the endurance-trained or untrained groups during the RSA test. The team-sport group also had a greater post-exercise blood lactate concentration, but not blood pH. There was a significant correlation between betam and RSA (r = 0.67; P < 0.05). Our findings show that young females competing in team sports have a larger betam than either endurance-trained or untrained females. This may be the result of the intermittent, high-intensity activity during training and the match play of team-sport athletes. The team-sport athletes also had a greater RSA than either the endurance-trained or untrained subjects. The greater total work by team-sport athletes was predominantly due to a better performance during the early sprints of the repeated-sprint bout.
authors.affiliation: Team Spart Research Group, School of Human Movement and Exercise Science, The University of Western Australia, Perth.
authors.forename: Johann
authors.initials: J
authors.lastname: Edg E
authors.forename: David
authors.initials: D
authors.lastname: Bishop
authors.forename: Stephen
authors.initials: S
authors.lastname: Hill-Haas
authors.forename: Brian
authors.initials: B
authors.lastname: Dawson
authors.forename: Carmel
authors.initials: C
authors.lastname: Goodman
mesh_terms: D000293:Adolescent; D000328:Adult; D001837:Body Weights and Measures; D015444:Exercise; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis / Q000097:blood; D009132:Muscles / Q000737:chemistry* / Q000502:physiology; D010101:Oxygen Consumption; D010807:Physical Endurance; D010809:Physical Fitness; D013177:Sports
chemical_list: D019344:Lactic Acid