The Effects of Cold Water Immersion and Active Recovery on Molecular Factors That Regulate Growth and Remodeling of Skeletal Muscle After Resistance Exercise

Abstract

• Cold water immersion post-exercise reduces muscle hypertrophy.
• Study with nine men: two resistance exercise sessions, with different recovery methods (cold water, active recovery).
• Muscle biopsies conducted at multiple intervals post-exercise.
• Increased mRNA for muscle growth factors (IGF-1 variants) and collagen after both recovery methods.
• Atrogin-1 mRNA decreased after both trials.
• No significant differences between cold water immersion and active recovery trials in gene and protein expression.

Introduction

• Cold water immersion is common for athletes post-exercise for recovery.
• Evidence suggests it might hinder long-term strength and muscle mass gains.
• Cold water immersion affects key muscle hypertrophy pathways (e.g. mTOR, IGF-1 signaling).
• Study aims to compare cold water immersion and active recovery on muscle molecular changes.

Materials and Methods

Ethical Approval

• Conducted with informed consent, adhering to ethical standards.

Experimental Design

• Randomized cross-over study with nine young, healthy men.
• Participants performed single-leg resistance exercises followed by either cold water immersion or active recovery.
• Muscle biopsies taken before and at intervals up to 48 hours post-exercise.

Strength Exercises

• Included lower-body exercises with supervised strength training.

Recovery Therapies

• Cold water immersion: legs in 10.3°C water for 10 mins.
• Active recovery: low-intensity cycling.

Muscle Tissue Collection and Analysis

• Biopsies were processed for RNA and protein analysis.
• Used RT-PCR and Western blotting techniques.

Results

• IGF-1 Ec mRNA expression increased post-exercise.
• GADD45 mRNA also increased significantly after both recovery methods.
• No significant differences in expression of growth factors and ECM genes between trials.

Figures

• Six figures illustrating changes in gene/protein expression post-exercise.

Discussion

• No significant difference in molecular responses between cold water immersion and active recovery.
• Cold water immersion attenuates muscle adaptation independently of changes in growth factors or ECM remodeling.
• Suggests cold water immersion affects other pathways not examined in this study.

Data Availability Statement

• Raw data will be provided without reservation.

Ethics Statement

• Approved by the University of Queensland's ethics committee.

Author Contributions

• Contributions detailed for all authors involved in the study.

Conflict of Interest

• No conflicts of interest were reported.

Acknowledgments

• Thanks to participants, sponsors, and technical advisors.

Funding

• Supported by grants from ACSM, ESSA, and Queensland University of Technology.

References

• Comprehensive list of all studies and sources cited throughout the paper.