Steady-state acid-base response at exercise levels close to maximum lactate steady state.
OBJECTIVE
To study acid-base status during a constant-load treadmill test at exercise levels close to the maximum lactate steady-state.


METHODS
Two tests were performed: one maximal and one steady-state at a load corresponding to the mean of the two ventilatory thresholds observed in the first test.


METHODS
University Sports Science Laboratory.


METHODS
Twenty-three male Sports Science students, aged 26.7 (+/- 4.9 SD) years, 176.1 (+/- 6.3) cm in height, and weighing 72.8 (+/- 6.7) kg.


METHODS
Capillary blood gases, metabolites, electrolytes.


RESULTS
Acid-base status variables declined significantly during the maximal test. Lactate concentrations were above the values observed at onset of blood lactate accumulation. All the blood variables did not vary significantly at the various experimental times, except pH values and PCO2 values. Bicarbonate concentration remained constant. Plasma potassium, chlorine and sodium concentration did not increase.


CONCLUSIONS
During a steady-state test at a load corresponding to approximately 80% of VO2max, the acid-base status in capillary blood remained constant even though the lactate concentration was over 4 mmol/L. However, despite the maintenance of a constant acid-base status, other physiological variables did not behave in the same fashion.
Peinado
Pedro J B
PJ
Facultad de Ciencias de la Actividad Fisica y el Deporte- INEF, Universidad Politécnica de Madrid, Spain. pedroj.benito@upm.es
Di Salvo
Valter
V
Pigozzi
Fabio
F
Bermúdez
Ana I P
AI
Peinado Lozano
Ana B
AB
Calderón Montero
Francisco J
FJ
Maffulli
Nicola
N
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001774:Blood Chemical Analysis; D001784:Blood Gas Analysis; D015444:Exercise / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood* / Q000378:metabolism; D008297:Male
D019344:Lactic Acid