Time to exhaustion at intermittent maximal lactate steady state is longer than continuous cycling exercise

Abstract

The maximal lactate steady state (MLSS) represents a submaximal intensity that may be important in prescribing both continuous and interval endurance training. This study compared time to exhaustion (TTE) at MLSS in continuous and intermittent (i.e., with pauses) exercise, investigating whether physiological variables differ between these exercise modes. Fourteen trained male cyclists volunteered for this investigation and performed an incremental test, several 30-min tests to determine two MLSS intensities (continuous and discontinuous protocol), and two randomized tests until exhaustion at MLSS intensities on a cycle ergometer. The intermittent or discontinuous protocol was performed using 5 min of cycling, with an interval of 1 min of passive rest. TTE at intermittent MLSS was 24% longer than TTE at continuous exercise (67.8 ± 14.3 min vs. 54.7 ± 10.9 min; p < 0.05; effect sizes = 1.04), even though the absolute power output of intermittent MLSS was higher than continuous (268 ± 29 W vs. 251 ± 29 W; p < 0.05). Additionally, the total mechanical work done was significantly lower at continuous exercise than at intermittent exercise. Likewise, regarding cardiorespiratory and metabolic variables, we observed greater responses during intermittent exercise than during continuous exercise at MLSS. Thus, for endurance training prescription, this is an important finding to apply in extensive interval sessions at MLSS. This result suggests that interval sessions at discontinuous MLSS should be used instead of continuous MLSS, as discontinuous MLSS allows for a larger amount of total work during the exhaustion trial.

Functional Threshold Power in Cyclists: Validity of the Concept and Physiological Responses

“…We found large limits of agreement between most variables, suggesting a high level of interindividual variability in the relationship between FTP 20 vs. FTP 60 and between both measurements vs. IAT. Even though TTE performance at FTP 20 fell within the expected range, the interindividual variability was higher (50.9 ± 15.7 min) than typically found at MLSS (55.0 ± 8.5 min [3] or 54.7 ± 10.9 min [15]). Researchers have investigated FTP predic- tive ability in diverse ways [11,14,21,25].…”

Occupational Medicine in cardiovascular risk prevention by ergometry and psycho test implementing physical activities in Public Health Institute employees

“…[22] Intermittent training shows better results than continuous one for lactate decreasing. [23] Such training influences maximal lactate steady state and delay time to exhaustion. [24] Time to exhaustion at maximal lactate steady state is similar for cycling and running.…”

Letter to the Editor

“…[3], we think there is also another likely reason for the higher [La] at MLSS, found by Li et al [7]. Since Beneke et al [4] reported the influence of test interruptions on MLSS determination, other studies have investigated the differences between the 'continuous' and 'intermittent' MLSS [2,5,6]. Beneke et al [4] demonstrated that the inclusion of 30-s pause after every 5-min (as used by Li et al [7]) modify the workload and [La] at MLSS when compared to continuous cycling protocol.…”

“…The mean [La] value at MLSS was 4.7 ± 1.5 mM (continuous protocol) and 5.7 ± 1.3 mM (intermittent protocol using 30-s pauses; p > 0.05 and Cohen's Effect Size -ES = 0.71), showing a trend to be higher when using the intermittent model [4]. The other 2 studies conducted by our group confirmed this fact, by using continuous and intermittent (1-min pause after every 5-min; ratio 5:1) MLSS determination during running ([La] = 3.7 ± 0.9 vs. 4.4 ± 1 mM; p < 0.02 and ES = 0.80) and cycling ([La] = 4.1 ± 0.9 vs. 4.9 ± 1.2 mM; p < 0.01 and ES = 0.76) [5,6] respectively. The conclusion by authors which [La] at MLSS was 5.4 mM in kayaking should be interpreted with caution.…”