Trimethylglycine (TMG) as an Adjuvant for Exercise Performance
Based on current evidence, trimethylglycine (TMG) cannot be recommended as an effective adjuvant for improving exercise performance as there is insufficient high-quality research supporting its use for this purpose.
Current Evidence on TMG for Exercise Performance
The available guidelines and research do not provide strong support for TMG as an exercise performance enhancer:
None of the major sports nutrition or exercise guidelines specifically recommend TMG for exercise performance enhancement 1.
The UEFA expert group statement on nutrition in elite football (2021) does not include TMG among its recommended ergogenic aids, while it does recommend other supplements like caffeine, creatine, beta-alanine, and nitrate with specific protocols 1.
Potential Mechanisms and Limited Evidence
TMG (also known as betaine) has been studied primarily for other purposes:
TMG has been investigated for its effects on lipid metabolism in experimental atherosclerosis models 2, 3, 4, showing some positive effects on cholesterol levels and lipid metabolism in animal studies.
In humans, TMG supplementation has been shown to decrease plasma homocysteine concentrations but did not affect body weight, body composition, or resting energy expenditure 5.
Comparison with Established Ergogenic Aids
When considering exercise adjuvants, it's important to compare TMG with supplements that have stronger evidence:
Creatine: Has well-established benefits for enhancing training capacity, muscle strength, power, and lean body mass 1.
- Protocol: Loading phase of ~20g/day for 5-7 days, followed by maintenance of 3-5g/day.
Caffeine: Substantial evidence supports its use for improving exercise performance 1.
- Protocol: 3-6 mg/kg body mass consumed ~60 minutes before exercise.
Beta-alanine: May improve high-intensity exercise and repeated sprint performance 1.
Nitrate: Can improve economy and endurance exercise performance 1.
Clinical Decision Making
When considering supplements for exercise performance:
Prioritize evidence-based options: Focus on supplements with strong clinical evidence and established safety profiles.
Consider individual goals: Different supplements may be appropriate depending on whether the goal is strength, endurance, or power.
Evaluate potential risks: All supplements should be evaluated for safety, potential side effects, and interactions with medications.
Quality assurance: If supplements are used, ensure they come from reputable sources with third-party testing to minimize contamination risks 1.
Conclusion
While TMG has shown some effects on lipid metabolism and homocysteine levels, there is insufficient evidence to support its use specifically as an ergogenic aid for exercise performance. Athletes and fitness enthusiasts would be better served by focusing on established ergogenic aids with stronger evidence bases, such as creatine, caffeine, beta-alanine, or nitrate, depending on their specific performance goals.
For those interested in improving exercise performance, a combination of proper training, nutrition, and potentially evidence-based supplements remains the most effective approach.