It is important to every man to be "fit" for his work. Fitness, however, does not solely depend upon food. All that ensures health ensures energy. Energy is expended by the heart in its never-ceasing labours, in the expansion and contraction of the lungs in the process of breathing, and in the movement of every muscle in the body; and no man can be fit unless his whole system works as exactly as the clock.

To keep fit it is essential to breathe pure air, to observe cleanliness, which so many ignore, exercise, environment, and care in eating. The man who sleeps with closed windows should learn that air is of much greater primary importance than food.

Under normal conditions we breathe nearly 25,000 times in twenty-four hours, and the air we exhale contains a dangerous gas, known as carbonic acid, which does much harm to the system, where it poisons the air.

In an unventilated bedroom the air contains four times as much of this gas as the air in the street, but if we may judge by what we see every morning in walking before most people are up, the bedroom windows of nine houses out of every ten are closed during most part of the year, and the pure air which is more important than food is excluded in favour of the poisonous mixture. If there was no ventilation whatever a man could not stay in his bedroom more than a few hours without losing his life.

Pure air, too, is essential to the digestion, and therefore to fitness, and the more a man passes through his lungs under normal conditions, the more he gets out of his food. It is partly for this reason that he should take regular exercise.

If a man breathes fifteen times a minute when he is writing at his desk, and thus uses 480 cubic inches of air, he only employs about one-fifth as much as if he were walking at the rate of four miles an hour. If he increases his speed he also increases his breathing, and takes in more air, just as when he decreases his speed he inhales less.

Thus, when walking very slowly the air inspired is double as much as when resting or sitting at work, and so it is that a man taking his exercise, by increasing the oxygen taken into his lungs, gets rid of the poisonous waste, and his system is cleaner in consequence.

In maintaining fitness a man should walk four miles at a stretch at a good pace at least once every day. It improves his circulation, every muscle and vital organ is helped, while the functions of the liver and stomach receive an impulse for good by every contraction and expansion of the lungs.

It is stated on authority that when our soldiers are on a quick march they step 116 times in a minute. I find that in walking at a similar pace I take 120 steps, but I am taller than the average man. A man should make his own pace, too, or he may lose power, just as the short soldier, with a naturally smaller stride, loses power when he is marching with taller men, because he is obliged to keep step with them.

It is an accepted rule that the power expended by the muscular system of a man weighing 150 lb., and doing an average amount of work daily, is equal to lifting 300 tons one foot off the ground; but the soldier with his kit on his back, which adds 50 per cent. to his labour, does much more than this on a long march, in addition to his expenditure of energy in other directions.

An hour's quick walking before breakfast makes a healthy man fit for the day, but he must not make the mistake of supposing that he can split up this time into two periods, for it is not the same thing. Slow walkers should gradually accustom themselves to a faster pace and longer distances, for fitness is not gained by a stroll. This needs mental as well as physical training until the habit is formed, when the healthy man at sixty or seventy may become as fit as if he were twenty years younger.

We Englishmen thrive on our morning tub of cold water, not because it is good for us, but in spite of it. A cold bath on rising from bed is taken when the system has the least power of resistance, and, however well the robust are able to stand it, it is not the best time. Eleven or 3.30 is very much better, but neither is convenient to the average man. Daily sponging with cold water at 60° F. and a weekly warm bath will remove the secretions, and maintain a clean skin.

It is important, too, where we labour. A ploughman has a much better chance of maintaining fitness and living a long life than a man who is confined to an office, badly lit and badly ventilated. Next to pure air he requires sunlight, but a man in a sedentary occupation can overcome these personal troubles if he chooses to keep in perpetual training - working, eating, sleeping, walking - to live, instead of living for perpetual pleasure. I hold, too, that faith in the great future life is an essential to that form of perfection in manhood to which all healthy men should aspire. There is no satisfaction in living without that.

No man can become fit for his place as a worker if he eats like a pig. We all eat too much, and most of us eat the wrong foods. Our belief in our insular safety is a continual incitement to indulge in luxurious living. While it is quite the right thing to live as economically as we can, that we may the better help our country and ourselves should a rainy day arrive, it is equally true that we should be much the better for it. Less poultry, less meat, and less fish - or, still better, neither one nor the other for middle-aged people at least - less milk and cream, except for the children, and more cereals, nuts, vegetables, and fruit, if more of the first-named are needed. No alcohol, less coffee, no afternoon tea - it is waste - for all these are luxuries, and detrimental at that. Drink is much the most useful in fruit.