Anaerobic threshold, skeletal muscle enzymes and fiber composition in young female cross-country skiers.
Anaerobic threshold (AT) and maximum oxygen uptake (max VO2) were determined in 15 young female cross-country skiers, aged 15--20 years, during incremental bycycle ergometer exercise. Succinate dehydrogenase (SDH), malate dehydrogenase (MDH), citrate synthase (CS) and lactate dehydrogenase (LDH) were analyzed biochemically and percentage of slow twitch fibres (%ST fibres, myosin adenosine triphosphatase staining) histochemically in muscle samples obtained from m. vastus lateralis. Max VO2 correlated significantly with anaerobic threshold in ml x kg-1 x min-1 (mlAT) but when AT was expressed in percent of max VO2 (%AT) the correlation was insignificant. Significant correlations were found between %AT and SDH (r = 0.63) and between mlAT and CS (r = 0.58). Max VO2 showed no significant correlations with the enzymes studied or %ST fibres. The results of the study seem to support the hypothesis that anaerobic threshold is related to oxidative capacity of muscle.
D000293:Adolescent; D000328:Adult; D002950:Citrate (si)-Synthase / Q000378:metabolism*; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000097:blood; D008291:Malate Dehydrogenase / Q000378:metabolism; D009132:Muscles / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism*; D007652:Oxo-Acid-Lyases / Q000378:metabolism*; D010807:Physical Endurance; D005082:Physical Exertion; D012119:Respiration; D013178:Sports Medicine; D013385:Succinate Dehydrogenase / Q000378:metabolism
D007773:Lactates; D010088:Oxidoreductases; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D013385:Succinate Dehydrogenase; D002950:Citrate (si)-Synthase; D007652:Oxo-Acid-Lyases