Hi Mike, I’ve read TLS and a bunch of your articles and they are game-changers! I started a cut in June, losing 4 pounds over 8 weeks and inches from my waist. I’m 47, 5’10” and now weigh about 131, 27″ waist. Things plateaued (hangry, busy) and I could feel myself losing strength, so I’ve already been reverse dieting and am at about 1750 cal per day working back toward my TDE. I just ordered your recommended calipers and see I’m at approx 23% body fat. Is it okay to finish my reverse diet and start bulking, or should I try to cut again?
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 .
Excellent article!, just wanted to ask a quick question in regards to maintaing my muscle and cutting body fat. I work out monday- friday, am eating very healthy and also taking in my body weight in protein per day. I weigh 195lbs but want to get to about 180-185 lbs. I am starting to do cardio to help cut down on my body fat and was wondering when do you think is the best time to do cardio to help decrease my body fat and but not my muscle growth ? Immediately following my workout? or a couple hours after my workout (after I have eaten dinner and protein shake). Thanks for your time