CAFFEINE STIMULATES LIPOLYSIS
Caffeine augments cyclic-AMP activity in fat cells; cyclic-AMP activates hormone-sensitive lipases to promote lipolysis (breakdown of lipids into free fatty acids) and release free fatty acids into the plasma. Increased plasma free fatty acid levels stimulate fat oxidation, thus conserving liver and muscle glycogen.
MY ADVICE
20-30 min before undertaking exercise, drink of cup of unsweetened coffee (expresso) or have a tablet of No-Doz, or a caffeine based pre-workout to stimulate lipolysis and spare your glycogen.