Correction: Exercise above the maximal lactate steady state does not elicit a V̇O2 slow component that leads to attainment of V̇O2max

Changes in physiological variables during a 60-min continuous test at maximal lactate steady state (MLSS) were studied using highly conditioned cyclists (1 female and 9 males, aged 28.3 ± 8.1 years). To determine power at MLSS, we tested at 8-min increments and interpolated the power corresponding to a blood lactate value of 4 mmol/L. During the subsequent 60-min exercise at MLSS, we observed a sequential increase of physiological parameters, in contrast to stable blood lactate. Heart rate drifted upward from beginning to end of exercise. This became statistically significant after 30 min. From 10-60 min of exercise, a change of + 12.6 ± 3.2 bpm was noted. Significant drift was seen after 30 min for the respiratory exchange ratio, after 40 min for the rate of perceived exertion using the Borg scale, and after 50 min for % [Formula: see text] and minute ventilation. This slow component of [Formula: see text] may be the result of higher recruitment of type II fibers. Key words: Rate of perceived exertion, heart rate, oxygen consumption, blood lactate, cycling

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Exercise above the maximal lactate steady state does not elicit a VO2 slow component that leads to attainment of VO2max

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0261 ◽

2020 ◽

Author(s):

David W. Hill ◽

Brian Keith McFarlin ◽

Jakob L. Vingren

Keyword(s):

Mathematical Modeling ◽

Steady State ◽

University Students ◽

Exercise Intensity ◽

Slow Component ◽

Primary Phase ◽

Maximal Lactate Steady State ◽

Third Phase ◽

Severe Intensity

There is a pervasive belief that the severe intensity domain is defined as work rates above the power associated with a maximal lactate steady state (MLSS) and by a VO2 response that demonstrates a rapid increase (primary phase) followed by a slower increase (slow component), which leads to VO2max if exercise is continued long enough. Fifteen university students performed five to seven tests to calculate power at MLSS (154 ± 29 W). The tests included 30 minutes of exercise at each of three work rates: (i) below (–2 ± 1 W) power at MLSS, (ii) above (+4 ± 1 W) the power at MLSS, and (iii) well above (+19 ± 8 W) power at MLSS. The VO2 response in each test was described using mathematical modeling. Contrary to expectation, the response at the supra-MLSS work rates had not two, but three, distinct phases: the primary phase and the slow component, plus a “delayed” third phase, which emerged after ~15 minutes. VO2max was not attained at supra-MLSS work rates. These results challenge commonly held beliefs about definitions and descriptions of exercise intensity domains. Novelty • the VO2 response at work rates that are too high to sustain a lactate steady state but not high enough to elicit VO2max features not two, but three, distinct phases • there is not consensus whether intensity domains should be defined by their boundaries or by the responses they engender

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Exercise slightly above the maximal lactate steady state reduces self-efficacy and increases negative affect

10.31236/osf.io/ecgkp ◽

2019 ◽

Author(s):

James Graeme Wrightson ◽

Louis Passfield

Keyword(s):

Steady State ◽

Negative Affect ◽

Power Output ◽

Self Efficacy ◽

Repeated Measures ◽

Physiological State ◽

Constant Load ◽

Peak Power Output ◽

Time To Exhaustion ◽

Maximal Lactate Steady State

Objectives: To examine the effect of exercise at and slightly above the maximal lactate steady state (MLSS) on self-efficacy, affect and effort, and their associations with exercise tolerance.Design: Counterbalanced, repeated measures designMethod: Participants performed two 30‐minute constant‐load cycling exercise at a power output equal to that at MLSS and 10 W above MLSS, immediately followed by a time‐to‐exhaustion test at 80% of their peak power output. Self-efficacy, affect and effort were measured before and after 30 minutes of cycling at and above MLSS.Results: Negative affect and effort higher, and self-efficacy and time to exhaustion were reduced, following cycling at MLSS + 10 W compared to cycling at the MLSS. Following exercise at the MLSS self-efficacy, affect and effort were all associated with subsequent time-to exhaustion. However, following exercise at MLSS + 10 W, only affect was associated with time-to exhaustion. Conclusions: Self efficacy, affect and effort are profoundly affected by physiological state, highlighting the influence of somatic states on perceptions and emotions during exercise. The affective response to exercise appears to be associated with exercise tolerance, indicating that the emotional, as well as physiological, responses should be considered when prescribing exercise training.

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