ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1999 December;39(4):300-8

Copyright © 2000 EDIZIONI MINERVA MEDICA

lingua: Inglese

Evaluating a test protocol for predicting maximum lactate steady state

Bacon L., Kern M.

Department of Kinesiology, San Francisco State University, San Francisco, CA, USA

Background. Maximum lac­tate ­steady ­state (­MLSS) is ­defined as the high­est ­steady ­state exer­cise lev­el one can main­tain ­while ­also main­tain­ing an equi­lib­ri­um ­between the elim­i­na­tion of ­blood lac­tate and the dif­fu­sion of lac­tate ­into the ­blood. ­MLSS is an excel­lent ­tool for assess­ing fit­ness lev­el, pre­dict­ing endu­rance per­for­mance, and design­ing train­ing pro­grams.
Methods. This inves­ti­ga­tion assess­es the valid­ity of the Lactate Minimum Test (LMT), ­which con­sists of induc­ing lac­tic aci­do­sis ­through a .VO2­peak ­test, fol­lowed by an ­eight-min­ute walk­ing recov­ery and an incre­men­tal exer­cise ­test, to deter­mine if the run­ning veloc­ity asso­ciat­ed ­with the min­i­mum lac­tate val­ue pre­dicts the ­MLSS veloc­ity. Following ­this LMT, two con­stant veloc­ity 28-min­ute ­runs ­were per­formed, one at the pre­dict­ed ­MLSS veloc­ity (­trial 1) and the oth­er 0.13 m sec-1 (4-8%) ­above the pre­dict­ed ­MLSS veloc­ity (­trial 2). Ten ­active ­female sub­jects par­tic­i­pat­ed (32±7 yrs (­mean±SD); 65.7±16.4 kg; .VO2­peak
40.0 ±7.5 ml·kg-1·min-1).
Results. During ­trial 1, ­there was a -0.6±0.3 ­mmol l-1 (­mean±SE) ­change in lac­tate. Based on a def­i­ni­tion of lac­tate ­steady ­state (LSS) as ­less ­than a 0.5 ­mmol·l-1 ­increase, ­this val­ue sig­ni­fied LSS. A sim­i­lar com­par­i­son dur­ing ­trial 2 ­revealed a 1.8±0.3 ­mmol·l-1 ­increase in lac­tate, sig­ni­fy­ing a work­load ­above LSS and there­fore con­firm­ing ­trial 1 as the max­i­mum LSS (­MLSS).
Conclusions. These ­results sug­gest ­that the ­test pro­to­col accu­rate­ly pre­dict­ed the ­MLSS veloc­ity.