Absence of training-specific cardiac adaptation in paraplegic athletes

The distinctive nature of left ventricular (LV) adaptation reported in able-bodied endurance- and power-trained athletes probably reflects the different hemodynamic loading patterns that occur during acute exercise. The exercise-induced hemodynamic loads in spinal cord injured athletes are different to those in able-bodied counterparts (lower venous return and stroke volume, higher heart rate). We sought to test the hypothesis that wall thickness, but not chamber dimension, would be larger in endurance- and power-trained spinal cord injured athletes compared with sedentary spinal cord injured subjects.

We undertook resting two-dimensional, motion-mode, and Doppler examinations of 11 power-trained, 10 endurance-trained, and 5 sedentary spinal cord injured volunteers and compared structural and functional LV data by using ANOVA. LV structural data were also analyzed after being scaled to body mass (BM)(0.33).

There were no statistically significant differences among groups for any of the LV structural or functional measurements. However, there was a trend for larger mean wall thickness (0.95 +/- 0.12 vs 0.83 +/- 0.10 cm) and left ventricular mass (193 +/- 57 vs 164 +/- 66 g) in athletes compared with sedentary individuals.

It seems unlikely that endurance and power training elicits distinctive patterns of LV enlargement in spinal cord injured athletes. Small adaptations of the left ventricle may occur with athletic training in the spinal cord injured athlete. Research within this population is complicated by extreme heterogeneity in important physical, physiological, and athletic-related variables.