The cardiovascular condition of five members of the University of B.C. cross country team was checked weekly with the Cameron Heartometer. Heartograph measures taken twenty-four hours before competition were compared to the coach's subjective appraisal of the athlete's performance to see if fluctuations in any of the measures corresponded to fluctuations in performance. A record of the runners' training load was also kept. Using case study methods the information above was observed and studied to see if the heartometer is a practical device for anticipating staleness, incipient infection or general inability to adapt to the training load. The autonomic nervous tone of the athlete is indirectly represented by the heartometer measures. The measures of the heartograph were also statistically interpreted to see which measures showed significant trends during the nine weeks of testing. Each of the five athletes showed results that were different than those of his teammates. One athlete, with a long history of endurance training, significantly improved most of the aspects of his cardiovascular condition in the short nine-week season. This runner ran well throughout the season with no apparent staleness. Another athlete, who has had severe attacks of asthma, performed well until attempting a particularly heavy amount of work. After this work he ran a very poor race. The heartograph showed a rest-to-work ratio that had dipped sharply from previous readings, on a graph taken twenty-four hours before this race. A third subject had been training all year. From the beginning of testing this runner showed strong pulse wave responses. However, his performance was not as would be expected from an athlete that was adapting well to his training. During the season the athlete had a slight nervous breakdown which indicates that he was not adapting to the stresses of his overall programme. With a reduction of training his running improved somewhat as did certain measures of his pulse wave. The fourth subject trained hard but did not perform as well as might be expected for an athlete undertaking this amount of training. The fifth man trained moderately throughout the season. This subject was basically a middle distance runner and participated in cross country in preparation for the track season. His heartograph measures showed gradual improvements and three - systolic blood pressure, pulse pressure and rest-to-work ratio - showed significant linear increase during the training period. This runner performed as expected in all races. Four measures of the pulse wave showed parallel development with improving cardiovascular condition; these were the diastolic surge, rest-to-work ratio, systolic blood pressure and pulse pressure. The rest-to-work ratio showed variations that on observation best indicated staleness or inability to adapt to the training load. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate