Grade Influences Blood Lactate Kinetics During Cross-Country Skiing

• Autores: Dain P. Laroche, Markus Amann, Kenneth W. Rundell
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 24, Nº. 1, 2010, págs. 120-127
• Idioma: inglés
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• Resumen

  • The purpose of this study was to examine the effects of level vs. graded skate skiing on capillary blood lactate (BLa), heart rate (HR), oxygen consumption ([latin capital V with dot above]o2), and training intensity prescriptions. Eleven Nordic skiers completed 2 submaximal skate roller skiing treadmill protocols during which intensity was increased either by grade (Ginc) or by speed (Sinc). The protocols were compared for prethreshold BLa, HR, and [latin capital V with dot above]o2 at lactate threshold (LT) and the HR/[latin capital V with dot above]o2 relationship. Additionally, double-pole (primarily upper body) and skating (arms and legs combined) protocols were used to measure peak [latin capital V with dot above]o2 and peak HR. Heart rate and [latin capital V with dot above]o2 at LT were lower during Ginc compared with Sinc (154.9 ± 6.8 b·min-1 vs. 162.0 ± 9.1 b·min-1 and 46.3 ± 2.8 ml·kg-1·min-1 vs. 49.1 ± 1.6 ml·kg-1·min-1, respectively, both p < 0.01). Prethreshold BLa and the HR/[latin capital V with dot above]o2 relationship were not different between the submaximal protocols. [latin capital V with dot above]o2peak and HRpeak were higher in skating compared with double poling (64.6 ± 1.8 ml·kg-1·min-1 vs. 60.3 ± 2.8 ml·kg-1·min-1, 192.6 ± 5.8 b·min-1 vs. 187.8 ± 6.7 b·min-1, respectively, both p < 0.01). Greater reliance on upper-body musculature during graded skiing and its associated lower aerobic capacity increases BLa when compared with level skiing. The leftward shift in the BLa vs. intensity curve during uphill skiing should be recognized to properly prescribe training intensity as well as interpret laboratory results.