The efficiency of human muscle has been measured (in the context of rowing and cycling ) at 18% to 26%. The efficiency is defined as the ratio of mechanical work output to the total metabolic cost, as can be calculated from oxygen consumption. This low efficiency is the result of about 40% efficiency of generating ATP from food energy , losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body. The latter two losses are dependent on the type of exercise and the type of muscle fibers being used (fast-twitch or slow-twitch). For an overall efficiency of 20 percent, one watt of mechanical power is equivalent to kcal per hour. For example, one manufacturer of rowing equipment calibrates its rowing ergometer to count burned calories as equal to four times the actual mechanical work, plus 300 kcal per hour,  this amounts to about 20 percent efficiency at 250 watts of mechanical output. The mechanical energy output of a cyclic contraction can depend upon many factors, including activation timing, muscle strain trajectory, and rates of force rise & decay. These can be synthesized experimentally using work loop analysis .
Protein is king when it comes to muscle growth, but don’t overlook carbs. If you’re looking to pack on lean mass, you must take in the right amounts and types of carbs each day. If your muscle glycogen stores (., the form in which carbs are stored in muscles) aren’t fully loaded every day, you’re not tapping into your body’s full growth potential. If your muscles are loaded with carbs (., glycogen), cell volume and protein synthesis will increase, and this means more muscle growth! Every serving of ISO MASS delivers 80 grams of time-release carbs for optimal delivery and storage in muscle tissue.
Warnings: Warnings: Keep Out Of Reach Of Children. Not for use by pregnant or nursing women, or persons under the age of 18. This product is intended for use by healthy individuals only. Always consult a physician before beginning this or any dietary supplement and/or training program. Do not use this product if you have a family history of prostate or kidney disease, endocrine condition, or any other medical condition. If you are taking any dietary supplement or prescription drugs, consult with your physician before using this product. Do not exceed suggested dosage to avoid potential adverse negative side effects.