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Dietary supplements affect the anabolic hormones after weight-training exercise
R M Chandler1, H K Byrne, J G Patterson
1Department of Kinesiology, University of Texas at Austin 78712.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|February 1, 1994
Summary
Nutritive supplements after weight-training exercise can favorably impact muscle growth. Carbohydrate and protein supplements stimulate insulin and growth hormone, creating an anabolic hormonal environment during recovery.
Area of Science:
- Exercise physiology
- Nutritional biochemistry
- Endocrinology
Background:
- Weight-training exercise significantly impacts hormonal profiles.
- Post-exercise nutrition is crucial for recovery and adaptation.
- Understanding the hormonal response to supplements is key for optimizing training outcomes.
Purpose of the Study:
- To investigate the effects of carbohydrate (CHO) and/or protein (PRO) supplements on hormonal responses following weight-training exercise.
- To determine if specific supplement compositions influence key anabolic and catabolic hormones during recovery.
- To assess the impact of post-exercise supplementation on insulin, growth hormone, testosterone, and IGF-I levels.
Main Methods:
- Nine experienced male weight lifters participated in the study.
- Participants consumed water (Control), carbohydrate (CHO), protein (PRO), or carbohydrate-protein (CHO/PRO) supplements.
- Venous blood samples were collected pre-exercise, post-exercise, and over an 8-hour recovery period.
Main Results:
- Exercise increased lactate, glucose, testosterone, and growth hormone.
- Carbohydrate and carbohydrate-protein supplements elevated insulin levels more than protein or control.
- Carbohydrate-protein supplementation resulted in higher growth hormone levels 6 hours post-exercise compared to protein or control.
- Testosterone levels declined with supplementation, but this was not linked to luteinizing hormone, suggesting increased clearance.
- Insulin-like growth factor I (IGF-I) levels were unaffected by any supplement.
Conclusions:
- Post-weight-training supplementation with carbohydrates and/or protein can create a hormonal environment conducive to muscle growth.
- Elevated insulin and growth hormone levels post-exercise, stimulated by supplements, may promote anabolic processes.
- The observed decrease in testosterone with supplementation warrants further investigation into its mechanisms and implications for muscle adaptation.