Cardiorespiratory Adaptations to Training at Specified Frequencies

Twenty young male volunteers were randomly assigned to one of four training groups or a control group in a study of the effect of various training frequencies on cardiorespiratory endurance. Training consisted of treadmill running at a rate of seven miles per hour for a ten-minute period. As each subject completed a ten-minute run the grade was increased one percent for the next training period. The group trained for one, two, three or five days per week for five weeks. Improvement was measured by pre- and post-administration of the Balke treadmill test, the Åstrand-Ryhming (A-R) test of physical fitness, the Taylor, Buskirk and Henschel test of maximal oxygen intake, and by maintaining a record of the number of training sessions completed. While the Balke test indicated significantly greater improvement for those in the five-day group, the other methods of measurement favored either the two- or three-day groups. Pre-training correlations among the three tests indicated that the A-R test was significantly related to the Balke and oxygen intake tests but that the latter tests were not related.