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 .
– your recommandation on daily need of protein is not very accurate, since 1- your are confusing kilograms and pounds, 2- your recommandation per Kg is very high.
1- you multiply LBS with a daily consumption per KG: as a result the daily consumption for a 190 pounder guy is of 270 g of proteins, which is quite ridiculous… it means eating more than one kilogram of beef a day, or 2,5 Kgs of eggs, namely 30 eggs a day ! 🙂
2- you suggest /Kg, which seems to be your personnal recommandation, how do you make it? It can be much lower for some people (/Kg), and much higher if you are a big runner (2g/Kg), all this depends of your activity.