Increased blood lactate level deteriorates running economy in World class endurance athletes.
Blood lactate accumulation is associated with development of muscle fatigue and negatively correlated to endurance performance. No research has quantified the effects of lactate presence at moderate levels of lactate accumulation. The purpose of the present study is to test whether two moderate blood lactate concentration levels affects running economy when running at the individual lactate threshold. 7 male world class endurance athletes with an average VO2max of 80.7+/-2.7 ml[dot operator]kg-1[dot operator]min-1 or 5.8+/-0.5 L[dot operator]min-1 participated in this study. After the VO2max test the subjects were resting or walking and in a random order tested for running economy at their lactate threshold velocity when the blood lactate level reached either 3 mmol[dot operator]L-1 or 5 mmol[dot operator]L-1. After a new 5 min exercising period at maximal aerobic velocity the crossover lactate value running economy testing was performed. Running economy was significantly (p<0.05) deteriorated from 0.668+/-0.044 to 0.705+/-0.056 ml[dot operator]kg-0.75[dot operator]m-1 or 5.5% (p<0.05) for blood lactate level of 3 mmol[dot operator]L-1 compared to 5 mmol[dot operator]L-1 respectively. Increased lactate level from 3 to 5 mmol mmol[dot operator]L-1 is thus accompanied by deteriorated running economy at lactate threshold running velocity. The deteriorated running economy at moderate levels of lactate concentration emphasizes the importance of avoiding intensities above lactate threshold in the early parts of a dominantly aerobic endurance competition. It also emphasizes the importance of a high VO2max for aerobic endurance athletes, and may partly explain the VO2 slow component as impaired running economy.
Copyright (C) 2016 by the National Strength & Conditioning Association.
Autor / Fonte:Jan Hoff, Øyvind Støren, Arnstein Finstad, Eivind Wang, Jan Helgerud Journal of Strength and Conditioning Research 2016 January 22