Lean Muscle, Power, Fuel, Recovery. Inner Armour lean muscle series whey protein is the perfect addition to your nutritional regimen. Inner Armour lean muscle series whey protein is designed to boost the free lean muscle-building peptides, while reducing cravings and increasing energy levels. Low temperature,, micro-filtered whey protein and whey protein hydrolysate have been clinically proven to be the most highly digestible and bioavailable peptide chain food. 24 grams of highly available protein, great tasting, instantized to mix easily.