L-carnitine transports medium-chain fatty acids across the mitochondrial membrane for utilization.

“So like your diet and your exercise. And the type of fuel itself is NAD+. We don't need to get into NAD precursors or NMN or NR, anything. And then the accessory fuel tank is your creatine phosphate. So creatine is your accessory fuel tank. Your NAD status, which is largely determined by your REM sleep and quality sleep and exercise along with supplementation as the fuel, the carnitine shuttle is carnitine palmitoyl coenzyme A. And that takes medium-chain fatty acids, it takes different molecules of fat.”