Quick fact. Ready? Beta Alanine is an amino acid often included in pre workout formulas, and is a large component of what gives someone a 'muscle pump' prior to a workout. This can be described as a tingly sensation in one's arms and legs as the Beta Alanine travels from the blood into muscle tissues.

Quick fact. Ready? Veins don't have valves in them like arteries do. Thus, there is not as much protection against blood flowing backwards!

Quick fact. Ready? The branch chain amino acids, leucine, isoleucine, and valine, are very important for synthesis of muscle, and are often contributors to energy during high intensity workouts. Out of all of them, leucine is the most anabolic, thus is contributes the most towards the building of stronger muscles.

Quick fact. Ready? The 'burn' that you feel during an intense workout is the build up of lactic acid in your muscles. That exact same lactic acid is actually the preferred energy source to be used by your heart. Lactic acid may be uncomfortable, but is certainly not the bad guy!

Quick fact. Ready? Working at different intensities of exercise determines whether one is burning more carbohydrates or fats as fuel. Higher intensities use mainly carbs, while lower and more prolonged intensity training makes use of fats.

Paulo Coelho