Quick Answer
Glycine Exercise Performance Randomized Trial has evidence relevant to safety, limits, and clinician-discussion contexts, but conclusions should stay close to the cited sources. One representative finding is: Out of those, three measured the effect of an acute supplementation, and three described the effect of a chronic supplementation, but no significant improvements on performance were found.
Key Takeaways
- 01Out of those, three measured the effect of an acute supplementation, and three described the effect of a chronic supplementation, but no significant improvements on performance were found. [Mielgo-Ayuso J (2021)]
- 02In summary, l-C supplementation with 3 to 4 g ingested between 60 and 90 min before testing or 2 to 2.72 g/day for 9 to 24 weeks improved high-intensity exercise performance. [Mielgo-Ayuso J (2021)]
- 03l-Carnitine (l-C) and any of its forms (glycine-propionyl l-Carnitine (GPL-C) or l-Carnitine l-tartrate (l-CLT)) has been frequently recommended as a supplement to improve sports performance due to, among others, its role in fat metabolism and in maintaining the mitochondrial acetyl-CoA/CoA ratio. [Mielgo-Ayuso J (2021)]
- 04The main aim of the present systematic review was to determine the effects of oral l-C supplementation on moderate- (50-79% V˙O 2 max ) and high-intensity (≥80% V˙O 2 max ) exercise performance and to show the effective doses and ideal timing of its intake. [Mielgo-Ayuso J (2021)]
The current Migaku evidence database contains 2 reusable source documents for Glycine Exercise Performance Randomized Trial. This answer focuses on safety, limits, and clinician-discussion contexts.
- Out of those, three measured the effect of an acute supplementation, and three described the effect of a chronic supplementation, but no significant improvements on performance were found. [Mielgo-Ayuso J (2021); evidence level 1]
- In summary, l-C supplementation with 3 to 4 g ingested between 60 and 90 min before testing or 2 to 2.72 g/day for 9 to 24 weeks improved high-intensity exercise performance. [Mielgo-Ayuso J (2021); evidence level 1]
- l-Carnitine (l-C) and any of its forms (glycine-propionyl l-Carnitine (GPL-C) or l-Carnitine l-tartrate (l-CLT)) has been frequently recommended as a supplement to improve sports performance due to, among others, its role in fat metabolism and in maintaining the mitochondrial acetyl-CoA/CoA ratio. [Mielgo-Ayuso J (2021); evidence level 1]
- The main aim of the present systematic review was to determine the effects of oral l-C supplementation on moderate- (50-79% V˙O 2 max ) and high-intensity (≥80% V˙O 2 max ) exercise performance and to show the effective doses and ideal timing of its intake. [Mielgo-Ayuso J (2021); evidence level 1]
- We found that TMAO pre-administration markedly prolonged the exhaustive time in mice. [Zou H (2024); evidence level 4]
Evidence levels are sorting aids, not final clinical grades. Level 1 usually indicates systematic-review style evidence, level 2 indicates randomized trials or public-health guidance, and lower levels need more cautious wording.
This page is educational. People with medical conditions, pregnancy, medication use, or unusual symptoms should ask a qualified clinician before changing supplements, medication, or treatment routines.
Sources