An electrocardiograph study of twenty champion swimmers before and after one-hundred and ten yard sprint swimming competition
Creators: name: Hunt, Edmund Arthur
Publisher: name: University of British Columbia
Year: 2011

description: It was believed that a study of athletes under the stress of competition would present a somewhat different challenge than would the same tests held under laboratory conditions. The belief was that actual competition would produce a far greater emotional and physiological stress than could be produced in an artificial setting. For this reason then, nineteen highly trained and healthy, teen-age swimmers of championship calibre were selected for study before and after sprint swimming competition. One swimmer was studied a second time, two years after the first testing, making a total of twenty sets of observations. The subjects were studied before the exercise to determine their resting blood pressures and pulse rates and to record their resting electrocardiograms. The swimming races were, for the most part, held in regularly scheduled meets and were distances of one-hundred and ten yards. Four observations were made following official time trials of similar swimming-events. The study was to-be concerned with the changes and recovery of the electrocardiograms, pulse rates and blood pressures following the races. In reviewing the literature, no similar study could be found that employed the use of serial electrocardiograms that would present a view of the recovery of the heart during a selected time interval immediately following actual competition. Therefore, this study concerned itself with a thirty minute recovery period beginning three minutes after the race. Each subject, then, had electrocardiograms taken at: three, six, nine, twelve, fifteen, twenty, twenty-five and thirty minute intervals following the "all-out" sprint. Blood pressure readings were also taken at regular intervals and the pulse rate was automatically recorded by the electrocardiograph. The results of these measurements indicated individual variations in blood pressure and pulse rate. However, general trends were observed in the measurements of the P-R interval, the ST segment and the T wave. The P-R interval, in twelve of the twenty cases, was prolonged. ST depression was seen in eight cases. The T wave was lowered considerably in all of the cases, with T inversion in nine of the athletes. Eighteen of the twenty observations showed one or all of the following major variations: PR prolongation, T inversion, ST depression. These three changes of the electrocardiogram, if: of sufficient degree, are taken as evidence of cardiac disease according to medical tests. Several studies of athletes observed after exercise have also pointed out that PR prolongation, T wave inversion and ST depression are to be taken as pathological variations. In the present study, these variations were not present in the resting recordings of any of the subjects. These variations did appear, however, at different times throughout the thirty minute recovery period. The deflections of concern, for the most part, had returned to normal by the end of the test. This evidence might then suggest that such variation, in healthy, young athletes, appearing after strenuous competition, would be indicative of functional adjustment of the myocardium to this situation of physical and emotional stress.