Effects of L-carnitine L-tartrate supplementation on muscle oxygenation responses to resistance exercise

What Was Tested

Researchers studied L-Carnitine in this randomized controlled trial publication.

Therefore, the primary purpose of this study was to determine the effects of LCLT supplementation on muscle tissue oxygenation during and after multiple sets of squat exercise.

Why It Was Studied

However, the mechanism of this response is unclear.

On day 22, subjects performed 5 sets of 15 to 20 repetitions of squat exercise with corresponding measures of thigh muscle oxygenation, via NIRS, and serial blood draws.

Who Took Part

The study group was 22, subjects.

PubMed indexes the participants as adults, men only.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

Because people in this L-Carnitine study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Blinding on both sides kept the subjects and researchers unaware of who received L-Carnitine.

Some subjects received a placebo instead of L-Carnitine, giving a reference point.

In the crossover set-up each of the subjects took both L-Carnitine and the comparison in turn, acting as their own control.

On day 21, forearm muscle oxygenation was measured during and after an upper arm occlusion protocol using near infrared spectroscopy (NIRS), which measures the balance of oxygen delivery in relation to oxygen consumption.

What Was Measured

On day 22, subjects performed 5 sets of 15 to 20 repetitions of squat exercise with corresponding measures of thigh muscle oxygenation, via NIRS, and serial blood draws.

PubMed files the paper under topics including Carnitine, Dietary Supplements, Exercise, Malondialdehyde, Muscle, Skeletal, Oxygen and Oxygen Consumption.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of L-Carnitine in 22, subjects.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2008 (Journal of strength and conditioning research), a journal based in United States.

More context: the L-Carnitine compound page, all human trials.