There are two divisions in this class, as may be shown in the case of the present world war. The first class embraces all the men in active service, with two subdivisions--officers who are over forty and officers and privates who are under that age. The second class comprises the men (and women, too, for that matter) who, unable to do service at the front, must support the troops in various ways behind the lines. It is said that it takes five men behind the line to support one man at the front, and, judging from the pressure that already has come upon our people, this is manifestly not an incorrect statement. These reserves must be kept in good physical condition, and with this end in view the writer has prepared a modified form of setting-up exercises which has been tested out with large numbers in actual practice. These exercises are intended to prepare the younger men for the more strenuous training which they are to undergo later; in the case of the older men, they are to be used before entering upon the ordinary day of business routine. After a great deal of study a system has been devised which answers the needs in both cases; it is not too strenuous for the older men, and it will add suppleness, vitality, and endurance to the physical assets of the younger men. A MODERN PHYSICAL SYSTEM We know how, in the stress of affairs brought about by war, not only individuals, but nations are suddenly awakened to the fact that what may have been good enough even a year ago is antiquated and out of date to-day. Under the pressure of war we are driven, whether we wish it or not, to put to immediate test virtually every fact of our daily lives. We find that almost every machine and well-nigh every method may be improved--in fact, that it must be improved. Boats, aeroplanes, guns, industrial processes, even the actual business of living itself, all are being submitted to the test of emergency and are being made over upon new lines. So it is with our setting-up exercises. We can no longer afford to waste time or motion or effort. We are teaching on an intensive scale and we must take nothing out of a man in preparation; rather we must add to his store of vitality and energy. Perhaps we find that the routine of his ordinary work will strengthen sufficiently his legs and arms. This is astonishingly true. What we must now do is to supple him, to quicken his co-ordination, to improve his poise, and to put his trunk and thorax into better shape. We must give him endurance, quickness of response, and resistive force. This, therefore, being our problem, we eliminate the arm and leg exercises and go directly for the trunk and thorax. We must quicken co-ordination and improve the man's rapidity of response to command. And standing out above all is this major principle: "No vitality should be taken out of a man by these setting-up exercises; he should not be tired out, but rather made ready for the regular work of the day." OUT-OF-DATE IDEAS