“…The most noticeable change in the ECG has been in the T wave, which has been used to designate ventricular repolarization (Guyton, 1966). Increases in the amplitude of the T wave with training are well documented (Tuttle and Korns, 1941;Wolf, 1953;Beckner and Winsor, 1954;Cureton, 1958;Rose and Dunn, 1964) in both athletes (Bedner and Winsor, 1954; Rose and Dunn, 1964) and middle-aged subjects (Cureton, 1958). However, it has been indicated (Cureton, 1958) that if training is too strenuous and/or prolonged the T wave amplitude may decrease.…”