The effects of conditioning on cardiorespiratory function in adolescent boys.

Pulse rate and oxygen consumption were measured for 19 boys (agen 12-13) assigned to either Distance, Interval, or No-Training regimens, during a 5 min. run at 6 m.p.h., zero % grade on a motor driven treadmill prior to a 12 week conditioning period, following conditioning, and after four months of deconditioning. Oxygen consumption was assessed by opencircuitry and heart rate monitored by direct electrocardiography. Both conditioning groups significantly improved cardiovascular fitness (Distance group: 175-152 beats/min. and Interval group: 175-159 beats/min.) at P less than .01, but no differences were noted between them. They differed significantly from the Control group (P less than .05) which showed no change (172-173 beats/min.). No significant differences occurred between any of the groups for Vo2 variables, but Within group analysis statistically favored the Distance group. Post-conditioning and -deconditioning comparisoms indicated taht deconditioning had a deleterious effect on cardiorespiratory function. Cardiorespiratory fitness improved to the extent that competitive running events of 2-6 miles are suggested for this age group, but as the data indicated, only after sufficient training. Task similarity of training and standard test and running volume apparently afforded a slightly greater improvement of cardiorespiratory fitness in the Distance group. Marked deterioration of fitness during deconditioning was attributed to complete absence of a training stimulus.