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Published on: April 28, 2023
Development and characterization of an overtraining animal model
Rodrigo Hohl1, Rodrigo Luíz Perroni Ferraresso, Renato Buscariolli De Oliveira
1Laboratory of Exercise Biochemistry (LABEX), Biochemistry Department, Biology Institute, State University of Campinas (UNICAMP), Campinas, Brazil. labex@unicamp.br
This study developed an endurance training-overtraining model in rats. Functional overreaching maintained performance, while nonfunctional overreaching led to performance decline and leukocytosis, offering insights into overtraining mechanisms.
Area of Science:
- Exercise Physiology
- Sports Science
- Animal Models
Background:
- Overtraining syndrome (OTS) is a complex condition affecting athletes.
- Understanding the physiological mechanisms of overtraining is crucial for prevention and management.
- Animal models provide a controlled environment to study OTS.
Purpose of the Study:
- To develop and validate a Wistar rat model for endurance training and overtraining.
- To analyze performance changes and key biomarkers during the training-overtraining protocol.
- To differentiate between functional overreaching (FOR) and nonfunctional overreaching (NFOR).
Main Methods:
- An 11-week running protocol with progressively increasing training load and decreasing recovery time was implemented.
- Performance was assessed weekly, with rats categorized into FOR and NFOR groups based on performance trends.
- Biomarkers including muscle citrate synthase activity and plasma glutamine/glutamate ratio were analyzed.
Main Results:
- The functional overreaching (FOR) group maintained performance levels similar to trained rats.
- The nonfunctional overreaching (NFOR) group exhibited a significant decline in performance and sustained leukocytosis.
- Both FOR and trained groups showed increased muscle citrate synthase activity and plasma glutamine/glutamate ratio compared to controls.
Conclusions:
- Performance decline in NFOR may be linked to reduced muscle oxidative capacity.
- Observed trends in plasma glutamine/glutamate ratio and leukocytosis in NFOR rats resemble findings in overtrained humans.
- This rat model serves as a valuable tool for investigating the causative mechanisms of performance decrements due to overtraining.
