Green Tea: Green tea and green tea extracts have been shown to activate the body's thermogenic fat-burning activity. A study published in the American Journal of Clinical Nutrition found that men who ingested the active ingredient in green tea (catechins) significantly reduced their total fat area, waist circumference, skinfold thickness, and subcutaneous fat area. As exercise physiologist Nick Coker explains in the article "Your Expert Guide to Green Tea," taking this ingredient with caffeine has been shown to make it even more effective.
L‐carnitine: This stimulant-free amino acid has been physique athletes' secret weapon for decades. Taken once or twice daily with food, it can also help your body convert stored body fat into energy, leaving you leaner and more defined. It does this by breaking up fatty acids so the body can use them for fuel. As Jim Stoppani, Ph.D., explains in "Your Expert Guide to L-Carnitine," it has also been shown in studies to support recovery from workouts, reduce muscle damage, and even reduce exercise-induced muscle soreness.