L-Carnitine – Energy & Fat Burner

L-Carnitine is effective, but its mechanism is specific: it transports long-chain fatty acids into the mitochondrial matrix for oxidation (β-oxidation). Without carnitine, fats cannot enter the mitochondria to be burned. Its effectiveness depends on two crucial conditions: muscles must have available carnitine (Wall et al., J Physiol, 2011 show that chronic supplementation + insulin increases muscle carnitine content by 21%) AND free fatty acids must be available (moderate-intensity, aerobic effort). In practice: L-Carnitine + 30g of carbohydrates (for insulin) + moderate cardio = a combination that optimizes the use of fat as an energy substrate.

Each form of carnitine has specific properties. L-Carnitine Tartrate: the best form for athletic performance and muscle recovery (absorbed quickly, studied in most sports research). L-Carnitine base: equivalent for lipid metabolism, slightly slower. Acetyl-L-Carnitine (ALCAR): crosses the blood-brain barrier, nootropic effects (memory, focus), less oriented toward pure lipolysis. Propionyl-L-Carnitine: cardiovascular benefit (peripheral circulation), of little relevance for standard athletic performance. For cutting and lipolysis: L-Carnitine tartrate or base. For focus and cognitive performance + lipolysis: ALCAR.