Aerobic fitness evaluation during walking tests identifies the maximal lactate steady state.
OBJECTIVE
The aim of this study was to verify the possibility of lactate minimum (LM) determination during a walking test and the validity of such LM protocol on predicting the maximal lactate steady-state (MLSS) intensity.


METHODS
Eleven healthy subjects (24.2 ± 4.5 yr; 74.3 ± 7.7 kg; 176.9 ± 4.1 cm) performed LM tests on a treadmill, consisting of walking at 5.5 km · h⁻¹ and with 20-22% of inclination until voluntary exhaustion to induce metabolic acidosis. After 7 minutes of recovery the participants performed an incremental test starting at 7% incline with increments of 2% at each 3 minutes until exhaustion. A polynomial modeling approach (LMp) and a visual inspection (LMv) were used to identify the LM as the exercise intensity associated to the lowest [bLac] during the test. Participants also underwent to 2-4 constant intensity tests of 30 minutes to determine the MLSS intensity.


RESULTS
There were no differences among LMv (12.6 ± 1.7%), LMp (13.1 ± 1.5%), and MLSS (13.6 ± 2.1%) and the Bland and Altman plots evidenced acceptable agreement between them.


CONCLUSIONS
It was possible to identify the LM during walking tests with intensity imposed by treadmill inclination, and it seemed to be valid on identifying the exercise intensity associated to the MLSS.
Catholic University of Brasília, 72022-900 Brasília, DF, Brazil. gmpuga@gmail.com
Guilherme Morais
GM
Puga
Eduardo
E
Kokubun
Herbert Gustavo
HG
Simões
Fabio Yuzo
FY
Nakamura
Carmen Sílvia Grubert
CS
Campbell
D000328:Adult; D000332:Aerobiosis; D006801:Humans; D007773:Lactates / Q000097:blood*; D008297:Male; D012016:Reference Values; D016138:Walking
D007773:Lactates