title: Attainment of maximal exercise criteria in boys and men.
abstract: BACKGROUND
  This study tested the hypothesis that the occurrence of a VO(2) plateau at maximal exercise would be greater in men versus boys. Secondary indicators of maximal effort also were examined.
  
  
  METHODS
  Sixteen boys (10.7+/-0.6 yrs) and 21 men (22.5+/-2.0 yrs) performed a graded exercise test on a treadmill at a constant speed of 8.04 km x hr(-1) with 2.5% increments in elevation. The men also performed a second test at 11.26 km x hr(-1) with similar increases in slope.
  
  
  RESULTS
  At 8.04 km x hr(-1) , VO(2) max was 52.3+/-6.0 and 52.5+/-5.1 ml x kg(-1) x min(-1) in boys and men, respectively (p>0.05). In the men, VO(2) max (53.3+/-5.4 ml x kg(-1) x min(-1) ) was higher (p<0.05) in the faster protocol. The percentage of men achieving the criterion was nearly double the percentage of boys (23.8 vs 12.5%), although the difference was not significant. Age-specific criteria heart rate (HR) and respiratory exchange ratio (RER) were achieved in a similar manner; however, more men (100%) than boys (86.7%) achieved an age-specific blood lactate (BLa) criterion (p<0.05). Plateau achievement increased to 33.0% in the 11.26 km x hr(-1) protocol, but was not significantly different from 8.04 km x hr(-1). HR, RER and BLa criteria achievement were comparable.
  
  
  CONCLUSIONS
  Maturation may influence the achievement of a plateau and BLa criteria, but not age-specific criteria for RER or HR.
authors.affiliation: Human Performance Laboratory, Ball State University, Muncie, IN, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Brown
authors.forename: A D
authors.initials: AD
authors.lastname: Mahon
authors.forename: D M
authors.initials: DM
authors.lastname: Plank
mesh_terms: D000328:Adult; D000367:Age Factors; D016009:Chi-Square Distribution; D002648:Child; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D011659:Pulmonary Gas Exchange / Q000502:physiology
chemical_list: D019344:Lactic Acid