Assaciations Between Two Exercise Intensity Indexes (%VO2max & %HRmax) During Submaximal Ergometery Exercise with Spastic Cerebral Palsy Teen-agers

American College of Sports Medicine (ACSM) presumed that for normal people, heart rate (HR) monitoring represents a promising tool for measurement, because it is a physiological parameter that correlates well with energy expenditure (VO2) and since HR monitoring in fielded exercise or rehabilitation is facilitated and feasible,many more studies used %HRmax as a suitable method for prediction of %VO2max. Recently, some researches showed that relationship between %HRmax and %VO2max described by ACSM is not applicable to some patients or handicapped people. The objective of this investigation was to determine the relationship between %HRmax and %VO2max in 25 teenagers with diplegia spastic cerebral palsy (12±2 years old). HR and VO2 responses to McMaster ergometry protocol monitored continuously at rest, end of each stage and the end of protocol in 25 teenagers with spastic participated in this study voluntarily and the consent of their parents as well as specialist physician. These parameters were then used for calculation of %HRmax and %VO2max in the subjects. Regression analyses were conducted to determine correlation between these indexes. Linear regressions of %HRmax and %VO2max were performed for the cases. The findings showed that %HRmax is not equivalent with %VO2max and the regression line is not according to the identity line (%VO2max = 1.55×%HRmax – 66, R = 0.76). In the other words, at each stage of protocol the values of %HRmax were very higher than %VO2max in comparison with those used by the ACSM. These results suggested that the relationship between these indexes in spastic patients is not similar to guidelines of ACSM and each disease depends on influence in physical and cardio-respiratory fitness, while neuromuscular system affects the relationship between exercise intensity indexes. Thus, the %HRmax versus %VO2max relationship should be determined directly in each disease.