Several years ago I discovered a unique and very effective means of strengthening the heart, lungs, stomach and other internal organs. I arranged a system of lessons, consisting of various pressure movements, which I termed an Inner Strength Course. As my experience with this course had been limited, I refrained at the time from presenting its fundamental theories to the general public. I issued the course in a series of four lessons, and the strength of each applicant was ascertained through questions before the course was sent to him. The experience with several hundred students, however, has so thoroughly confirmed the value of this method of internal vitality building that I am now in a position where I can present the ideas upon which it is based to the general public. The usual price of this course was five dollars, and several thousand courses were sold at this price, each student naturally receiving a certain amount of personal attention. The same ideas, however, are presented in this chapter, with the warning that those who use the pressure exercises recommended must take care to avoid pressing upon the internal organs beyond their resisting power. The various forms of pressure movements recommended are clearly illustrated and those who are not especially strong should begin with a very mild pressure and with the open hand placed upon the abdomen or chest, though where ordinary or unusual strength is possessed, the side of the open or closed hand could be used. These exercises are especially valuable for strengthening the heart where the pressure movements are used very freely near this particular organ. They can be highly recommended for strengthening the stomach though they should not be used immediately after a meal. I referred to their value in the chapter on constipation in connection with the treatment of this ailment. After a long trial this system of increasing the internal strength is highly recommended, and will be found of special value as a means of varying the health-building methods that may be adopted for securing throbbing vitality. They are not a necessary part of the plan of body building especially recommended in this volume, but are presented merely as a valuable means of varying your efforts in working for increased vitality. It is an interesting fact that in some forms of athletics, the body is subjected to a certain amount of internal stimulation similar to that which I have systematized in these movements. This is especially true in wrestling, where the vital organism is often compelled to endure a great deal of pressure of this kind. The same is true of American football, although this is too violent for those who are not in an unusually vigorous condition.