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Immune Response of Elite Enduro Racers to Laboratory and Racing Environments: The Influence of Training Impulse and Vibration

Kirkwood, Lewis; Ingram-Sills, Lesley; Taylor, Mark Dunlop; Malone, Eva; Florida-James, Geraint


Lewis Kirkwood


Introduction: Understanding the sport-specific immune response elicited during both training and competition is imperative to maximise athlete health and performance. Despite a growing population of professional enduro mountain bike athletes, little is known about the recovery of the immune system following enduro racing events. Methods: Nine international level elite enduro mountain bike athletes (age 24.3 ± 2.4 years, height 178.5 ± 8.7 cm, mass 76.5 ± 12.5 kg) completed a laboratory-based maximal exercise test (LAB) on a cycle ergometer and competed in an international mountain bike enduro race event (RACE). Blood samples were taken before, immediately after, and 1 h after LAB and before, 1 h after, and 17 h after RACE. Leukocyte subsets were enumerated using seven-colour flow cytometry. Lucia’s training impulse (LuTRIMP) and vibration exposure (VIB) were quantified during RACE. Results: Seven participants were included in the final analyses. There was a significant (p < 0.05) increase in neutrophil count alongside a reduction of cytotoxic lymphocyte cell subsets of both the innate (CD3−/CD56+ NK-cells and CD3−/CD56dim NK-cells) and adaptive (CD8+/CD62L−/CD45RA− T-cells and CD8+/CD27+/CD28− T-cells) components of the immune system one hour after RACE. All cell counts returned to baseline values 17 h afterwards (p > 0.05). Cell subset redistribution from pre- to post-one-hour time points (%Δpre-post1h) in cell subsets with potent effector functions (Neutrophils, CD3−/CD56+ NK-cells, CD8+/CD62L−/CD45RA− T-cells, CD8+/CD27+/CD28− T-cells, and CD3−/CD56dim/CD57− NK-cells) was significantly greater at RACE than LAB (p < 0.05). VIB was shown to be a superior predictor of %Δpre-post1h CD4+ T-cells, CD4+ early T-cells, CD4+ naïve T-cells, and NK cells as compared with LuTRIMP on its own (ΔR2 = 0.63 − 0.89, p < 0.05). Conclusions: The race event offers a greater challenge to the immune system than LAB, and potentially, whole body vibration is a key component of training load measurement in mountain bike applications.

Journal Article Type Article
Acceptance Date Apr 24, 2021
Online Publication Date Apr 26, 2021
Publication Date 2021-04
Deposit Date May 4, 2021
Publicly Available Date May 4, 2021
Journal International Journal of Environmental Research and Public Health
Publisher MDPI
Peer Reviewed Peer Reviewed
Volume 18
Issue 9
Article Number 4603
Keywords mountain biking; training load; recovery; leukocyte redistribution
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Immune Response Of Elite Enduro Racers To Laboratory And Racing Environments: The Influence Of Training Impulse And Vibration (2.1 Mb)

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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