2011-02-01

New study with Vitargo

Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans: the dual role of muscle carnitine in exercise metabolism.
Wall BT, Stephens FB, Constantin-Teodosiu D, Marimuthu K, Macdonald IA, Greenhaff PL.
J Physiol. 2011 Jan 4.

 

This is the FIRST study that shows multiple weeks of carnitine supplementation can lead to an increase in MUSCLE carnitine (all prior studies have shown NO increase). Notably, it took 24 weeks to show significant changes.

The KEY element that created the increase was ingestion of ENOUGH carbohydrate to raise the amount of insulin in the blood to a high enough concentration to activate the transport system for carnitine into muscle

The carbohydrate that was chosen was Vitargo (80 g + 2 g of Carnitine Tartrate, 2x/day); the Control group received only Vitargo (NO carnitine).

The subjects were non-elite triathletes, who took one of the two two supplements for 24 weeks (at breakfast time and then 4 hrs later).

Those taking Vitargo + Carnitine did not gain weight; those taking Vitargo alone gained 2.4 kg after 24 weeks (they did not measure if it was fat, muscle, or combination changes on body weight).

At 24 weeks those taking Carnitine + Vitargo had a 30% greater amount of MUSCLE carnitine than the Vitargo alone group.

When the subjects performed an 80% of maximum exercise capacity test, their experience of exertion, or difficulty, was significantly lower in only the Carni + Vitargo group (the intense exercise seemed easier for them).

In the Carni + Vitargo group significantly less glycogen or carbohydrate was used as fuel during the 50% or 80% of maximum exercise tests, with a much greater amount of fat being used as a fuelthis was linked to much less lactic acid being produced in the muscle during exercise.

At 24 weeks the Carni + Vitargo group had significantly higher exercise performance in a 30 minute all out exercise test (after a 50% of max, and an 80% of max study)--this suggests the subjects were able to better produce energy (or had more muscle glycogen remaining).

Clearly, increasing muscle carnitinethrough supplementation of an appropriate amount of carbohydrate and L-carnitine tartratecan have a dramatic impact on muscle metabolism and exercise performance but it takes more than 12 weeks, and perhaps up to 24 weeks, to show the dramatic differences.