A study on the effect of physical load of baseball umpire, during a baseball game in the summer

Abstract

The purpose of this study was to investigate the effects of physical loads, measured physiologically and biochemically, on baseball umpires during a baseball game in hot weather in the summer.These baseball games were held under the high temperature of about 30°C, a high humidity of 70% and high levels of solar radiation with a black-globe temperature of 45°C.The results obtained were as follows.1) The decreases in umpires' body weights immediately after the game were significant without exception, being about 1.19kg (1.7%). This could have been due to perspiration during the baseball game.2) Blood pressures, systolic and diastolic, were observed to have decreased significantly after the game.3) Total protein, albumin, total cholesterol, blood urea nitrogen, uric acid and creatinine in blood were observed to have significantly increased after the game.4) The serum electrolytes sodium, chloride, calcium and phosphorus showed a significant increase after the game, but potassium was observed to have significantly decreased then.5) Protein and creatinine in the urine increased significantly, but the entire urine volume decreased significantly due to perspiration.6) The average energy consumption of the umpire during a baseball game was about half as much as that of a player.The total amount of physical exercise by the former was ‘mild’ in degree as compared with that of the latter.The physical load produced by the umpiring labor presumably resulted mainly from the heat stress brought about by exposure to the summer heat for a long time.7) The physical loads were different depending on the position of the umpire, the umpire-in-chief having the greatest load, followed in descending order by the second-base umpire, the first-base umpire and the third-base umpire.