l carnitine l tartrate or acetyl Acetyl-L-Carnitine – Core Nutritionals NOW Foods Acetyl-L-Carnitine 500mg -
Description
It contributes to electrolyte balance* and supplies the body with important nutrients, especially during or after heavy sweating and intense activities

Kreider, R

Many people already use one or more of the supplements found in stacks, just not in combination

Biochem J 228:545550