Sex- and age-specific blood lactate recovery kinetics after high-intensity exercise in trained youth: A model-based analysis

Author Identifier (ORCID)

Anthony J. Blazevich: https://orcid.org/0000-0003-1664-1614

Abstract

Purpose: Post-exercise lactate recovery kinetics during growth remain poorly characterized, particularly in girls, limiting understanding of how age interacts with sex-specific metabolic adaptations. This study examined age- and sex-related differences in blood lactate recovery following high-intensity exercise from childhood to adolescence, focusing on lactate exchange (γ₁) and removal (γ₂) capacities. Methods: Seventy-six trained participants (41 boys, 35 girls) aged 10–17 years completed a 60 s all-out rowing test. Participants were stratified into four age groups: 10.0–11.9, 12.0–13.9, 14.0–15.9, and 16.0–17.9 years. Blood lactate concentrations were monitored over a 60-min passive recovery period and analyzed using the biexponential Freund model to estimate γ₁ and γ₂. End-exercise ([La]end) and peak ([La]max) lactate concentrations were measured, and absolute lactate quantities were calculated relative to lean body mass (QLaend, QLamax). Results: Blood lactate concentrations and quantities increased with age, with boys showing higher QLaend and QLamax from 14 years onward (p < 0.001), likely reflecting greater lean mass and power output. Both γ₁ and γ₂ declined significantly with age (from 16 and 14 years, respectively; p < 0.05), indicating reduced lactate handling capacities. Girls consistently exhibited higher γ₁ values than boys (p < 0.001), which may indicate more favorable lactate exchange characteristics. Conclusions: This study provides the first detailed characterization of post-exercise lactate recovery kinetics in growing girls, offering novel insight into female-specific metabolic adaptations and their interplay with age. These developmental patterns enhance understanding of age-associated metabolic adaptations and may inform sex- and age-tailored training strategies in pediatric populations.

Keywords

Anaerobic capacity, boys, girls, lactate exchange capacity, lactate removal capacity, lean body mass

Document Type

Journal Article

Date of Publication

1-1-2026

Publication Title

European Journal of Applied Physiology

Publisher

Springer

School

Centre for Precision Health / School of Medical and Health Sciences

RAS ID

95148

Comments

Bardin, J., Maciejewski, H., Diry, A., Blazevich, A. J., Thomas, C., & Ratel, S. (2026). Sex- and age-specific blood lactate recovery kinetics after high-intensity exercise in trained youth: A model-based analysis. European Journal of Applied Physiology. Advance online publication. https://doi.org/10.1007/s00421-026-06212-x

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Link to publisher version (DOI)

10.1007/s00421-026-06212-x