This quote was from the early 1900's by none other than the great Eugen Sandow. A true pioneer in Physical Culture training/lifestyle.
"You may go through the list of exercises with dumbbells a hundred times a day, but unless you fix your mind upon those muscles to which the work is applied, such exercise will bring but little, if any, benefit. If, upon the other hand, you concentrate your mind upon the muscles in use, then immediately development begins." Eugen Sandow
Really think about this… Now think about yourself and how you train..
Do you truly know the intricate details of what and how your training?
Do you really understand how the entire body from head to toe is supposed to operate together in said movements you do?
Do you understand the stimulus you are trying to apply in each practice session? If so, do you understand what science has taught us about the appropriate recovery from each specific stimulus?
Being healthy, getting strong, lean, improving performance, etc. are about appropriate stimulus being applied and the principles of said stimulus being honored. Far to many are exercising to often, to intense, to mindless for all the wrong reasons. If you want to get lean then send the correct stimulus to your body with proper nutrition, rest, and general light activity. If you want to get stronger than pick your exact goal, choose the appropriate stimulus you wish to use and honor the scientific principles that go along with it. Don't try to cheat yourself or science. This doesn't leave you healthy and strong, yet broken and weak while full of torturous stories in the end. Learn, create, test. retest. and grow as a human being in the process.