Effect of aerobic training status on both maximal lactate steady state and critical power

Abstract

This study aimed at assessing the sensitivity of both maximal lactate steady state (MLSS) and critical power (CP) in populations of different aerobic training status to ascertain whether CP is as sensitive as MLSS to a change in aerobic fitness. Seven untrained subjects (UT) (maximal oxygen uptake = 37.4 ± 6.5 mL·kg(-1)·min(-1)) and 7 endurance cyclists (T) (maximal oxygen uptake = 62.4 ± 5.2 mL·kg(-1)·min(-1)) performed an incremental test for maximal oxygen uptake estimation and several constant work rate tests for MLSS and CP determination. MLSS, whether expressed in mL·kg(-1)·min(-1) (T: 51.8 ± 5.7 vs. UT: 29.0 ± 6.1) or % maximal oxygen uptake (T: 83.1 ± 6.8 vs. UT: 77.1 ± 4.5), was significantly higher in the T group. CP expressed in mL·kg(-1)·min(-1) (T: 56.8 ± 5.1 vs. UT: 33.1 ± 6.3) was significantly higher in the T group as well but no difference was found when expressed in % maximal oxygen uptake (T: 91.1 ± 4.8 vs. UT: 88.3 ± 3.6). Whether expressed in absolute or relative values, MLSS is sensitive to aerobic training status and a good measure of aerobic endurance. Conversely, the improvement in CP with years of training is proportional to those of maximal oxygen uptake. Thus, CP might be less sensitive than MLSS for depicting an enhancement in aerobic fitness.

Resposta Fisiológica E Perceptual Na Velocidade Crítica E Ponto De Compensação Respiratória

“…Todavia, no presente estudo, os tempos-limites (Figura 1) situaram-se entre ~116 s (primeira preditiva) e ~721 s (terceira preditiva), que estão em conformidade com as sugestões de Hill et al 31 e Greco et al 32 para as preditivas de VC (ou PC). Assim, apesar da possibilidade de VC ter sido superestimada, os procedimentos atenderam aos critérios estabelecidos na literatura e apresentaram valores baixos de EPE (Figura 1).…”

Discussion of “Can measures of critical power precisely estimate the maximal metabolic steady-state?” – Is it still necessary to compare critical power to maximal lactate steady state?

“…Within the current literature, there are numerous studies demonstrating that CP exceeds the intensity at which MLSS occurs, at least when the CP is derived from trials ranging between 2 and 15 min, and by using the 2-parameter models in different sport modalities (Pringle and Jones 2002;Dekerle et al 2003). Moreover, this difference is independent of status training as verified by Greco et al (2011). Surprisingly, even so, Keir et al (2015) modelled CP using trials between 1 and 20 min, as well as the 3-parameter model proposed by Morton (1996), which it is known to produce the lowest CP derivation, as demonstrated by Bull et al (2000).…”

Agreement analysis between critical power and intensity corresponding to 50% in cycling exercise

“…The t lim was measured to the nearest second. Individual W' and CP estimates were derived from the four constant work rate prediction trials by least-squares fitting of the following regression models: a) nonlinear power output (P) vs. time to exhaustion (t lim ): The W' and CP estimates from the three equations were compared to select the best fit using the model associated with the lowest standard error of the estimate (SEE) for CP 8,22,23 . Breath-by-breath VO 2 data were recorded continuously during all tests and were reduced to 15-s stationary averages.…”