The small study, published in the Journal of Strength and Conditioning Research , used Lonza's Carnipure ingredient and involved eight men (average age 22) taking different doses of the supplement and undertaking bouts of resistance exercise.
The researchers, led by Barry Spiering from the University of Connecticut, report that both one and two gram doses were effective in reducing markers of oxidative stress and improving recovery, which may lead to formulations with lower doses but equal efficacy.
"We are pleased that the finding of the study will allow consumers to enjoy the benefits of Carnipure now at a more affordable level," said Thomas Brancato, NAFTA head of marketing and sales, Lonza.
The volunteers received daily supplements containing zero, one or two grams of L-carnitine L- tartrate (Carnipure) for three weeks and then asked to perform resistance exercise.
Blood samples were taken to measure serum carnitine levels, lactate, and glucose levels, and the subjects were asked to rate their perceived muscle soreness.
The study was performed in a randomised, repeated design.
"The primary finding of this investigation was that supplementing with one gram of L-carnitine L- tartrate per day for three weeks afforded similar benefits as a two gram daily dose," reported Spiering and co-workers.
Markers of metabolic stress were reduced by similar levels in both dose groups, while perceived muscle soreness 72 hours after exercise was similar between the one and two gram dose groups and significantly less that the zero gram control group.
The results support previous findings about the benefits of the ingredient for post-exercise markers.
L-carnitine is reported to play a critical role in fat and energy metabolism, being involved in the transport of long-chain fatty acids into the mitochondria where they are metabolized for energy.
"These results further expand on our extensive scientific database of testing of Lonza's Carnipure ingredients," said Kevin Owen, head of technical and scientific affairs, Lonza.
Lonza reported in February that sales of L-Carnitine for food and pharma had increased, mainly due to demand from the US, which has managed to defend its market share in the face of Chinese competition.
The company also offers a low-cost L-carnitine for the feed sector.
Source: Journal of Strength and Conditioning Research Volume 21, Number 1, Pages 259-264 "Responses of criterion variables to different supplement doses of L-carnitine L-tartrate" Authors:
B.A. Spiering, W.J. Kraemer, J.L. Vingren, D.L. Hatfield