Distribution of Energy Adjustment of Speed Records of running events illustrate the adjustment of speed to the length of the race. The 100 and 220 yard dashes are run at full speed. The 220 is run at a faster average rate than the 100 yard dash because maximum speed is not attained until the runner is at least 50 yards from the start. During the first 50 yards the runner must accelerate from zero speed at the start to the maximum speed. Thus at least half of the 100 yard dash is completed before maximum speed is attained. When the race is continued to 220 yards the sprinter can maintain maximum speed for the last 150 yards. Patton was probably running faster than 24 m.p.h. during the latter portions of the dashes. The 440 yard dash cannot be run at full speed all of the way. The speed must be lowered about 3 m.p.h. (14 per cent) below maximum or the runner will exhaust himself before the 440 yards have been run. In order to run 880 yards the speed must be reduced about 5.5 m.p.h. (25 per cent) below the maximum. In order to complete the 1,000 yard and the mile distances, the speed must be reduced nearly one-third (29 and 33 per cent) below the maximum rate. In races of this distance steady state of physiological activity must be established. High concentrations of lactic acid must be endured and large quantities of oxygen must be acquired. In races two miles and longer, the rate of physiological activity attained is well below the maximum steady state level. The lactic acid concentration and the oxygen debt are small and the runner finishes the race in a condition which would allow him to run farther. Races of 15 miles and longer are run at approximately the same rate which is about half the maximum speed. This rate is well tolerated by the trained athlete. He finishes with the heart rate only mildly elevated and the breathing is fairly easy. The limiting factors in long distance races appear to be the nutritional status and the condition of the feel and legs. In every distance event the athlete exerts himself at the highest rate of energy production which can be maintained over the distance. In races in which a steady state of physiological activity is established (440 yards and longer), the runner increases his speed just before the end of the race and finishes the race nearly exhausted. A runner who finishes the race with "something left" could have finished in a shorter time either by running at an increased speed throughout the race or by starting his finish "kick" earlier.		Home Components of Physical Fitness Clinical Examination Differences Between Fit and Unfit Men Physiological Elements of Fitness The Step Test The Effects of Training on the Physiological Systems Work Output Physical Condition of Muscle Application of Muscular Force Maintaining Optimum Strength Tests of Muscular Strength Strength and appearance Strength as a measure of physical fitness Strength as affected by organic problems Strength as prophylaxis Role of inactivity in production of disease Lack of Sociability in Work Lactic Acid System Muscular Form Capillary Growth Heart Size Heart Rate Training produces physicochemical changes Muscular Strength Nervous Stimulation and Muscular Strength Quality of Champions Factors Which Limit Skill Kinesthesis Balance Reaction Time Muscular Tension Visual Aim Skill Center in the Brain Endurance for Exhaustive and Moderate Work Distribution of Energy