title: Blood lactate after maximal and supramaximal exercise in 10- to 12-year-old Bolivian boys. Effects of altitude and socioeconomic status.
abstract: The aim of this paper was to analyze the effects of chronic hypoxia and socioeconomic level on blood lactate concentrations obtained after maximal exercise and a 30-s Wingate test in 145 Bolivian boys (mean age: 10.8 years). Among the boys studied at high altitude (HA) (La Paz, 3600m) and at low altitude (LA) (Santa Cruz de la Sierra, 420m), 23 (HAHSES) and 48 (LAHSES) were from a high socioeconomic status (HSES), and 44 (HALSES) and 30 (LALSES) from a low socioeconomic status (LSES). The pubertal development was evaluated by salivary testosterone level ([T]). Blood samples were collected from the earlobe for blood lactate determination 2 min after cessation of maximal exercise ([L]v) and of a 30-s Wingate test ([L]w). Results (means +/- SD) showed: (1) [T] was significantly lower at HA: HA (HSES + LSES): 139.0 +/- 46.6 vs LA (HSES + LSES) = 186.2 +/- 53.7 pmole.1-1 (p = 0.0001). There was no significant difference between HAHSES and HALSES but LALSES was significantly lower than LAHSES. When the four groups were pooled, significant positive correlations between [L] and [T] were found; (2) for a same level of socioeconomic conditions, [L]v and [L]w were significantly lower at HA: HAHSES = 4.9 +/- 1.5 vs LAHSES = 7.4 +/- 2.1 and HALSES = 4.8 +/- 1.4 vs LALSES = 6.3 +/- 1.5 mmole.l-1 for [L]v; HAHSES = 5.1 +/- 1.0 vs LAHSES = 6.2 +/- 1.4 and HALSES = 4.6 +/- 1.0 vs LALSES = 5.3 +/- 1.4 mmole.l-1 for [L]w; (3) except for [L]v at HA, the HSES boys exhibited higher [L]v and [L]w than the LSES children for a same altitude; (4) there were significant linear relationships between the power developed during the 30-s Wingate test and [L]w.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratory of Physiology and Sports Biology, Faculty of Medecine, Clermont-Ferrand, France.
authors.forename: N
authors.initials: N
authors.lastname: Fellmann
authors.forename: B
authors.initials: B
authors.lastname: Beaune
authors.forename: J
authors.initials: J
authors.lastname: Coudert
mesh_terms: D000531:Altitude; D001838:Bolivia; D002648:Child; D002908:Chronic Disease; D015444:Exercise; D006801:Humans; D000860:Hypoxia / Q000097:blood; D007773:Lactates / Q000097:blood*; D008297:Male; D012741:Sexual Maturation; D012923:Social Class
chemical_list: D007773:Lactates