title: Energy system contribution to 400-metre and 800-metre track running.
abstract: As a wide range of values has been reported for the relative energetics of 400-m and 800-m track running events, this study aimed to quantify the respective aerobic and anaerobic energy contributions to these events during track running. Sixteen trained 400-m (11 males, 5 females) and 11 trained 800-m (9 males, 2 females) athletes participated in this study. The participants performed (on separate days) a laboratory graded exercsie test and multiple race time-trials. The relative energy system contribution was calculated by multiple methods based upon measures of race VO2, accumulated oxygen deficit (AOD), blood lactate and estimated phosphocreatine degradation (lactate/PCr). The aerobic/anaerobic energy system contribution (AOD method) to the 400-m event was calculated as 41/59% (male) and 45/55% (female). For the 800-m event, an increased aerobic involvement was noted with a 60/40% (male) and 70/30% (female) respective contribution. Significant (P < 0.05) negative correlations were noted between race performance and anaerobic energy system involvement (lactate/PCr) for the male 800-m and female 400-m events (r = - 0.77 and - 0.87 respectively). These track running data compare well with previous estimates of the relative energy system contributions to the 400-m and 800-m events. Additionally, the relative importance and speed of interaction of the respective metabolic pathways has implications to training for these events.
authors.affiliation: School of Human Movement and Exercise Science, University of Western Australia, Crawley, Australia. rduffield@csu.edu.au
authors.forename: Rob
authors.initials: R
authors.lastname: Duffield
authors.forename: Brian
authors.initials: B
authors.lastname: Dawson
authors.forename: Carmel
authors.initials: C
authors.lastname: Goodman
mesh_terms: D000293:Adolescent; D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010725:Phosphocreatine / Q000378:metabolism; D012420:Running / Q000502:physiology*; D012737:Sex Factors; D013647:Task Performance and Analysis; D014142:Track and Field / Q000502:physiology*
chemical_list: D010725:Phosphocreatine; D019344:Lactic Acid