ISSN:
1439-6327
Keywords:
Lactataemia
;
Lactate thresholds
;
Maximal muscle exercise
;
Aging
;
Training
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary To study the effects of age and training on lactate production in older trained subjects, the lactate kinetics of highly trained cyclists [HT,n = 7; 65 (SEM 1.2) years] and control subjects with low training (LT,n = 7) and of similar age were compared to those of young athletes [YA,n = 7; 26 (SEM 0.7) years], during an incremental exercise test to maximum power. The results showed that the lactacidaemia at maximal oxygen uptake ( $$\dot VO_{2 max} $$ ) was lower for HT than for LT (P〈0.05) and, in both cases, lower than that of YA (P〈0.001). The respective values were HT: 3.9 (SEM 0.51), LT: 5.36 (SEM 1.12), and YA: 10.3 (SEM 0.63) mmol·1−1. At submaximal powers, however, the difference in lactacidaemia was not significant between HT and YA, although the values for lactacidaemia at $$\dot VO_{2 max} $$ calculated per watt and per watt normalized by body mass were significantly lower for HT (P〈0.001) and LT (P〈 0.02). These results would indicate that the decline in power with age induced a decline in lactacidaemia. Yet this loss in power was not the only causative factor; indeed, our results indicated a complementary metabolic influence. In the older subjects training decreased significantly the lactacidaemia for the same submaximal power (P〈0.01) and from 60% of $$\dot VO_{2 max} $$ onwards (P〈0.05); as for YA it postponed the increase and accumulation of lactates. The lactate increase threshold (Th1a−,1) was found at 46% $$\dot VO_{2 max} $$ for LT and at 56% $$\dot VO_{2 max} $$ for HT. The lactate accumulation threshold (Th1a−,2) was observed at approximately 80% $$\dot VO_{2 max} $$ for all three groups but at a value significantly different in each group. At Th1a−,2 the lactate value of HT was 2 (SEM 0.19) mmol · 1−1 thus closer to the value normally associated with the increase threshold instead of the accumulation threshold. In conclusion, the reduction in lactacidaemia was enhanced by training. Furthermore, the modification in the lactate kinetics with aging indicated that training at an intensity corresponding to a lactacidaemia of 2 and 4 mmol·1−1 was inadequate for master endurance athletes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00868133
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