Brain and nervous system always come first in starting to build muscular power that is to last and be always at your command. The basis of power depends upon the rapidity with which the muscles respond to mental impulses. Properly developed muscles are finely-fibered, and react instantly to the impulse of the motor cells of the brain――the cells which tell the muscles to shoot out at once. Now let anything such as alcohol, tobacco, loss of sleep or immoral habits, fasten on the youth and all attempts to get the full strength out of muscles, no matter how big they are, will be useless. The reason is that the brain cells have been affected――they cannot act as they should and so the muscles cannot respond to the impulse. This is the cause of so many first-class boxers taking the final count. Success has made them careless; they neglect the rules of the physiologic game, they drink a little, smoke and indulge in other habits which affect their nervous system. They go on the stage breathing the foul and poisonous atmosphere while exhibiting, are necessarily late to bed and while still keeping up their MUSCULAR training neglect the fact that every day they are injuring their nervous motility. It is so little noticed that no attention is paid to the matter. But when it comes to a battle after such a career――even if careful training has been done weeks before the contest――the effect is shown, and down the champion goes before a less experienced boxer, one not so strong in the muscles but one whose full brain and nervous force has remained uncontaminated. Then, sad to relate, THIS champion goes the same way. So you see that mere gross muscular structure is valueless――except it is needed for daily labor, where it exists as mere animal automatism――unless it is under the immediate control of a highly-organized nervous system free from disease and abuse. So delicate is this nervous element of the body in getting the muscles to respond, that I have tested hundreds of athletes――including myself――by a very sensitive instrument which shows the response of the muscles to the condition of the brain cells. A youth who has lived a perfect life――physiologically speaking――is kept from one half of his night’s sleep. The next day he is tested and there is a difference shown in the rapidity of muscular response. The difference in a tenth of a second in a blow makes all the difference between a champion and a loser, and this tenth of a second can be brought about by the loss of one night’s rest. How must it be then when the youth has lost several, or been breathing foul air with heavily working lungs?