A Novel Approach to Determining the Alactic Time Span in Connection with Assessment of the Maximal Rate of Lactate Accumulation in Elite Track Cyclists
2023 (English)In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 18, no 2, p. 157-163Article in journal (Refereed) Published
Abstract [en]
Purpose: Following short-term all-out exercise, the maximal rate of glycolysis is frequently assessed on the basis of the maximal rate of lactate accumulation in the blood. Since the end of the interval without significant accumulation (talac) is 1 of 2 denominators in the calculation employed, accurate determination of this parameter is crucial. Although the very existence and definition of talac, as well as the validity of its determination as time-to-peak power (tPpeak), remain controversial, this parameter plays a key role in anaerobic diagnostics. Here, we describe a novel approach to determination of talac and compare it to the current standard. Methods: Twelve elite track cyclists performed 3 maximal sprints (3, 8, and 12 s) and a high-rate, low-resistance pedaling test on an ergometer with monitoring of crank force and pedaling rate. Before and after each sprint, capillary blood samples were taken for determination of lactate accumulation. Fatigue-free force–velocity and power–velocity profiles were generated. talac was determined as tPpeak and as the time point of the first systematic deviation from the force–velocity profile (tFf). Results: Accumulation of lactate after the 3-second sprint was significant (0.58 [0.19] mmol L−1; P < .001, d = 1.982). tFf was <3 seconds and tPpeak was ≥3 seconds during all sprints (P < .001, d = − 2.111). Peak power output was lower than maximal power output (P < .001, d = −0.937). Blood lactate accumulation increased linearly with increasing duration of exercise (R2 ≥ .99) and intercepted the x-axis at ∼tFf. Conclusion: Definition of talac as tPpeak can lead to incorrect conclusions. We propose determination of talac based on tFf, the end of the fatigue-free state that may reflect the beginning of blood lactate accumulation.
Place, publisher, year, edition, pages
Human Kinetics , 2023. Vol. 18, no 2, p. 157-163
Keywords [en]
anaerobic diagnostics, fatigue-free time span, force–velocity profile, maximal rate of blood lactate accumulation
National Category
Sport and Fitness Sciences
Research subject
Physiotherapy; Centre - Swedish Sports Technology and Performance Research Centre (SPORTC)
Identifiers
URN: urn:nbn:se:ltu:diva-95606DOI: 10.1123/ijspp.2021-0464ISI: 000932931300008PubMedID: 36596309Scopus ID: 2-s2.0-85147234247OAI: oai:DiVA.org:ltu-95606DiVA, id: diva2:1736401
Note
Validerad;2023;Nivå 2;2023-02-24 (joosat);
2023-02-132023-02-132024-03-07Bibliographically approved