Maximum Rate of Work Work which requires an energy expenditure greater than 700 Calories per hour cannot be continued for much longer than one hour by an untrained man. Unless the man carrying the 43 pound load up the 35.8 per cent grade was well trained, he could not be expected to climb at 1.5 m.p.h. for more than an hour, as the energy expenditure at this rate is 890 Calories per hour. If the speed is reduced to 1.0 m.p.h., the energy requirement is reduced to 680 Calories per hour and the work can be sustained for a longer period. If the distance is great, the speed should be reduced so that the climber is not exhausted by the work. Efficiency must be sacrificed for endurance in order to accomplish work of long duration. If the distance is short, greater speed or heavier loads are necessary if the work is to be performed with the greatest efficiency. The well-trained individual is able to carry on work at a higher level of energy expenditure; thus he is able to perform work at higher speeds for longer periods. Racing Plan The steadiness in the rate of work is also a factor in efficiency. Work is done more efficiently if it is carried on at a steady rate. As shown before, it costs energy to accelerate. In distance races, whether running, swimming, rowing or bicycling, energy must be conserved and a steady state established at a dangerously high level of energy expenditure. Under these conditions the race will be finished in the shortest time if the athlete has maintained a speed at which a maximum steady state level has been established for the number of minutes required for the event. Then, at the proper distance before the end of the race, he increases the speed so that the maximum oxygen debt is reached at the finish. In this race plan the maximum energy is expended in the most economical manner. If the maximum energy has not been used in a race and the competitor has not finished in exhaustion, he has not turned in his greatest possible performance. Physiologic factors are not the only ones which enter into the efficiency complex. Other important factors such as genetic, environmental, and economic are discussed elsewhere.		Home Pace Motivation Measures of Endurance Computation of Dietary Requirement Work Efficiency Maximum Steady State Work Inefficiency of Anaerobic Work Estimation of Work Efficiency Efficiency of Grade Climbing Low Economy of Slow Work Maximum Rate of Work Levers of the Body Fatigue and Recovery General Fatigue Symptoms Anxiety State Organic Fatigue Cortical Motor and Sensory Centers Effect of Exercise on Mental Work Visual Fatigue Muscular Fatigue Fatigue Prevention and Recuperation