Adaptations to training at the individual anaerobic threshold.
The individual anaerobic threshold (Th(an)) is the highest metabolic rate at which blood lactate concentrations can be maintained at a steady-state during prolonged exercise. The purpose of this study was to test the hypothesis that training at the Th(an) would cause a greater change in indicators of training adaptation than would training "around" the Th(an). Three groups of subjects were evaluated before, and again after 4 and 8 weeks of training: a control group, a group which trained continuously for 30 min at the Th(an) intensity (SS), and a group (NSS) which divided the 30 min of training into 7.5-min blocks at intensities which alternated between being below the Th(an) [Th(an) -30% of the difference between Th(an) and maximal oxygen consumption (VO2max)] and above the Th(an) (Th(an) +30% of the difference between Th(an) and VO2max). The VO2max increased significantly from 4.06 to 4.27 l.min-1 in SS and from 3.89 to 4.06 l.min-1 in NSS. The power output (W) at Th(an) increased from 70.5 to 79.8% VO2max in SS and from 71.1 to 80.7% VO2max in NSS. The magnitude of change in VO2max, W at Th(an), % VO2max at Th(an) and in exercise time to exhaustion at the pretraining Th(an) was similar in both trained groups. Vastus lateralis citrate synthase and 3-hydroxyacyl-CoA-dehydrogenase activities increased to the same extent in both trained groups. While all of these training-induced adaptations were statistically significant (P < 0.05), there were no significant changes in any of these variables for the control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Keith
S P
SP
Environmental Physiology Section, Defence and Civil Institute of Environmental Medicine, North York, Ontario, Canada.
Jacobs
I
I
McLellan
T M
TM
D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000693:Anaerobiosis / Q000502:physiology; D006003:Glycogen / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology; D006651:Histocytochemistry; D006801:Humans; D007773:Lactates / Q000097:blood; D008168:Lung / Q000378:metabolism / Q000502:physiology; D008297:Male; D009132:Muscles / Q000166:cytology / Q000201:enzymology / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D010806:Physical Education and Training; D011659:Pulmonary Gas Exchange / Q000502:physiology
D007773:Lactates; D006003:Glycogen