Evaluation of methods used to determine anaerobic work capacity by blood lactate and oxygen debt / 体力科学

ABSTRACT

A study was conducted to examine the efficacy of indicators of anaerobic work capacity or estimations of anaerobic energy expenditure by measuring &Delta; blood lactate and O<SUB>2</SUB> debt after short-term maximal exercise. Eight male subjects performed cycle ergometer pedaling against 5.5-7.0 kp resistance with maximal effort for 45 s. After pedaling, venous blood samples were drawn serially at 1 min intervals from 1 to 10 min, for measurement of peak blood lactate. Anaerobic energy expenditure was determined in terms of both alactacid and lactacid energy expenditure, on the basis of &Delta; blood lactate (L-method) and O2 uptake kinetics (D-method) during recovery.<BR>The following results were obtained<BR>1) The correlation coefficient between lactate and performance was higher (about 0.3-0.5) when lactate was expressed as the estimated value of lactate production rather than &Delta; blood lactate. A significant relationship (r=0.740, p<0.05) was found between lactate production and peak power.<BR>2) When O<SUB>2</SUB> uptake after recovery for 60 min did not recover to the baseline of O<SUB>2</SUB> uptake at rest, O<SUB>2</SUB> debt was calculated using a baseline of O<SUB>2</SUB> uptake just before the end of recovery. This O<SUB>2</SUB> debt was significantly correlated with work at any time of recovery.<BR>3) There was a significant relationship between lactate production and lactic O<SUB>2</SUB> debt, which was significantly correlated with work.<BR>4) When lactacid energy was calculated using a formula of 1.7×&Delta; blood lactate and 0.3 kcal/g lactate, there was no significant difference between anaerobic energy expenditure calculated by the L- and D-methods for up to 30 min during recovery.<BR>It was concluded that a) the estimated value of lactate production and O<SUB>2</SUB> debt calculated using a baseline of O<SUB>2</SUB> uptake just before the end of recovery could be employed as an indicator of anaerobic work capacity, and b) &Delta; La multiplied by a coefficient of 1.7 and 0.3 kcal/g lactate was more appropriate for estimating anaerobic expenditure in short-term maximal cycle ergometer pedaling.