FATIGUE AND OVERTIME WORK

New Zealand Listener, Volume 5, Issue 125, 14 November 1941, Page 11

FATIGUE AND OVERTIME WORK

(Written tor "The Listener" by DR.

H. B.

TURBOTT

See Director Ot

the Division of School Hygiene, Health Department )

E all know what it is to feel tired, pleasantly jaded, or flat X out with fatigue. The balance between wear and repair in the body is upset. In exercise, lactic acid is disposed of almost as rapidly as it appears; it is oxidised by the oxygen brought to the muscles by the blood. If the exercise is kept up at a constant speed, the lactic acid in the muscle tises slowly from the low resting value to a level at which the rate of formation and removal are equal. During hard and violent exercise lactic acid is formed far quicker than it can be disposed of by the biggest oxygen intake of which the body is capable. We accumulate lactic acid in the tissues and blood stream. We overdraw our account during the exercise and repay the debt later. We rest. The muscles burn up their accumulation of lactic acid. Next, that in the tissues and blood diffuses back slowly into the muscles to be burnt up too. Fatigue disappears, and we feel fresh and » rested, Have you not noticed this as you work? A spell puts you right again. At the end of the week, you, a clerical

worker, may be really fatigued, yet can potter about in the garden on a long Friday evening, and do quite a lot of "work." Another set of muscles and body tissues are concerned. Or on a Saturday half way through the afternoon, your back is breaking with weed-ing-a spell-back to the task-after-noon tea--lawn or hedge cutting, digging, planting, it doesn’t matter what. With little spells and changes of occupation much more work is accomplished than you’d thought possible. But it was the little spells that really let you get it all done, Other Types of Fatigue Muscular fatigue, explained above, is teadily overcome by resting. But there are other "fatigues." Remember the short "bursts" of a footballer, the quick sharp changes of pace, the excitement -the body metabolism is temporarily upset, and the strain can be demonstrated by abnormal substances in the urine and increased cells in the blood. His fatigue is more complicated, Take the iron foundry worker or the dweller in the tropics. Fatigue at the end of their day will be more than muscular; body fluids and reserves of salt will be depleted, hindering muscle recovery. In factories, conditions should be pleasant, or there will be added to muscle fatigue the more wearing nervous and glandular over activitythere will be irritated employers and angry workmen, both piling up extra fatigue from these causes, _ Fatigue becomes terribly important in war time. Employers, private and government, are apt to overlook the dangers of overtime work, and how important ‘spells are in maintaining production. The British Government, in its recent crisis, appealed for extra work. Factories began working 24 hours a day, seven days a week, cancelling all holidays. At first there was an increase in output, but after two months of extreme effort, absenteeism increased and men arrived late for work. Frequently men worked on Sunday at double pay and then took a day off in the middle of the week. Fewer Hours, More Work Sunday labour was then discontinued by the Royal Ordnance factories, Production was not reduced. One factory, after reducing hours, set a new record for one week’s production. It is now recommended that a weekly maximum of 55 or 56 hours be observed. It is proved again that increased hours of work, above an optimal point, varying with different industries, do not in- crease production proportionately, or may even result in a decrease. When heavy overtime is worked for prolonged periods, the general health of the workers is undermined. Reducing hours where overtime has been prolonged increases output; but if overtime has gone on to the point of undermining health, reducing hours below the optimum

evel fails to effect the required increase of production. These are the conclusions that an English committee has arrived at, following a close study of war industries. Male worker, this story is apparently all in your interests. Fatigue occurs if bodily wear and repair are not in balance. A balance must be kept between work and discipline on the one hand, leisure and play on the other. Now think of your wife, tied to long hours in the home with the constant strain of the children. How about arranging spells for her, a holiday away from the child-ren-for her, too, hard work tempered with play! (Next week: "Vegetables," by Dr. |‘ Muriel Bell)