Post-competition blood lactate concentrations as indicators of anaerobic energy expenditure during 400-m and 800-m races

Abstract

The relationships between anaerobic glycolysis and the average velocity (v) sustained during running were studied in 17 top level athletes (11 males and 6 females). A blood sample was obtained within 10 min of the completion of major competitions over 400 m, 800 m and 1500 m and the blood lactate concentration [la]b was measured. In both male and female athletes [la]b was related to the relative performance, as expressed as a percentage of the athlete's best v of the season. Over 400 m, r = 0.85 (P less than 0.01) and r = 0.80 (P less than 0.05) in males and females, respectively. Over 800 m, the corresponding values were r = 0.76 (P less than 0.01) and r = 0.91 (P less than 0.01). In male runners [la]b was correlated to v: r = 0.89 (P less than 0.01) and r = 0.71 (P less than 0.02) over 400 m and 800 m, respectively. No relationship to relative performance or v was obtained over 1500 m. Energy expenditure during competition running was estimated in male runners from the [la]b values. This estimate was based mainly on the assumption that a 1 mmol.1-1 increase in [la]b corresponded to the energy produced by the utilization of 3.30 ml.O kg-1. The energy cost of running was estimated, by dividing the estimated total energy expenditure by the race distance, at 0.211 ml.kg-1.min-1 over 800 m and 0.274 ml.kg-1.m-1 over 400 m.(ABSTRACT TRUNCATED AT 250 WORDS)

Testes de pista para avaliação da capacidade lática de corredores velocistas de alto nível

“…In the analysis, uneven weights were found in the relationships between the [La] and the distances ran with no significant correlations between the Dmax 30 and [La] max 30 (r = -0.44; p < 0.05), and significant association between the Dmax 60 at the [La] max 60 (r = -0.82; p < 0.05). This last figure can be fitted in the higher level found by other authors, with competitive performance in 400/800 s running and 30-60 s duration treadmill running (r between -0.67 and -0.89) (18)(19)(20)(21)(22) . Despite the limitations of the size of the sampling in the present study, the higher value of the association between Dmax 60 and the [La] max 60 is in accordance to the theoretical model proposed, stating that the max 60 is more dependent from the AnA than the max 30 , and it can be more adequate to deplete it.…”

“…The peak [La] after intense exercising is frequently used as a measure to indicate the energy releasing by the lactic (20) , but there is much controversy on the meaning and consequences of the lactate production during and after the exercise (23)(24)(25) . Some determining factors for this discussion and its consequent implications are associated to the possible [La] dependences on "foreign" factors, such as the lactate diffusion ability (26) , blood volume (27,28) , and variability of its measurement (19) .…”

Anaerobic performance in masters athletes

“…Peak blood lactate concentration is widely used as an indirect measure of anaerobic glycolytic activity or capacity to discriminate between athletes of different glycolytic capacity and performance levels [92] and correlates with muscle lactate following maximal anaerobic performance [31,72]. In older sedentary men aged 60-70 years, peak blood lactate has been shown to be lower than young man aged 20-30 years following a maximal 30-s cycle ergometer test [102,105].…”

An analysis of performance in human locomotion

“…At _ La max ; it is some 40 s (Margaria et al 1964;Grassi et al 1995). Note that the 20 mM lactate concentration is not an upper limit in blood lactate accumulation: this value is somewhat higher in power athletes (Lacour et al 1990), has been overtaken after bicarbonate administration (Nielsen et al 2002), and does not correspond to the maximal blood lactate concentration attained at the end of intermittent supramaximal exercise bouts (Osnes and Hermansen 1972).…”

“…For prolonged exercise, relying on aerobic metabolism, _ E max should correspond to _ VO 2max : Yet _ VO 2max can be sustained only for some 8-10 min (Lacour et al 1990;Padilla et al 1992), although di Prampero et al (1993) assumed 14 min in their modelling of middle-distance running. For longer exercise duration, _ E max is lower than _ VO 2max ; and we must account for the fraction of _ VO 2max actually sustainable over a given time (fractional utilisation of _ VO 2max , F u ).…”