L-carnitine L-tartrate is a popular supplement in some endurance athletes and bodybuilders.  L-carnitine is an important chemical found in the mitochondria (the cells energy center) where it helps break down long chain fatty acids and promotes oxygen consumption.  Intense weight training restricts muscle blood flow and oxygen delivery, which interferes with muscle cell function and damages cell membranes.  In young adults, L-carnitine L-tartrate supplements reduced chemical damage to tissues after exercise, and promoted muscle tissue repair and recovery.

Several studies found that L-carnitine L-tartrate promoted recovery and prevented free radical tissue damage in intensely training young men.  A sophisticated study from the University of Connecticut found similar results in middle aged men.  Muscle deterioration with age is a serious problem that decreases physical performance, quality of life, and can lead to premature death.  The study showed that L-carnitine L-tartrate supplements reduced markers of tissue breakdown, free radical formation, and muscle soreness after exercise.  (Metabolism Clinical and Experimental, 59:  1190-1199, 2010)