title: Differences in lactate exchange and removal abilities between high-level African and Caucasian 400-m track runners.
abstract: The present study aimed to investigate (1) whether high-level 400-m track runners of different ethnic origin displayed divergent post-run blood lactate concentrations (p400m[La]) and (2) if this discrepancy was based on differences in lactate exchange and removal abilities. Twenty male African (n = 12) and Caucasian (n = 8) runners, paired in terms of personal record, performed (1) an all-out 400-m run to measure p400m[La] at 3, 5 and 7 min into recovery and (2) a 1-min 25.2 km h(-1) running (not maximal but standardized) exercise followed by 90-min passive recovery to determine individual blood lactate recovery curves (IBLRC). IBLRCs were fitted to a bi-exponential time function: [Formula: see text] where γ 1 and γ 2 denote lactate exchange ability between the previously worked muscles and blood, and overall ability for lactate removal, respectively. The quantity of lactate accumulated at the end of the 1-min exercise (Q LaA) was also estimated. Our study showed that after the all-out 400-m run, p400m[La] was lower in African than in Caucasian runners at 3 and 5 min but not at 7 min into recovery. After the standardized exercise, γ 1 and γ 2 were lower (p < 0.01) and Q LaA was higher (p < 0.05) in African than in Caucasian runners. These data suggest that for similar performance levels, ethnicity involves differences in lactate accumulation, exchange and removal.
authors.affiliation: Exercise Physiology Laboratory, LPE EA 4338, University of Savoie, 73 376 Le Bourget du Lac Cedex, France. carine.bret@univ-reims.fr
authors.forename: Carine
authors.initials: C
authors.lastname: Bret
authors.forename: Jean-René
authors.initials: JR
authors.lastname: Lacour
authors.forename: Muriel
authors.initials: M
authors.lastname: Bourdin
authors.forename: Elio
authors.initials: E
authors.lastname: Locatelli
authors.forename: Marco
authors.initials: M
authors.lastname: De Angelis
authors.forename: Marcello
authors.initials: M
authors.lastname: Faina
authors.forename: Abderrehmane
authors.initials: A
authors.lastname: Rahmani
authors.forename: Laurent
authors.initials: L
authors.lastname: Messonnier
mesh_terms: D000328:Adult; D056352:Athletes; D044383:Black People; D006801:Humans; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D012420:Running; D044465:White People
chemical_list: D019344:Lactic Acid