Improved exercise performance in pediatric heart transplant recipients after home exercise training

Abstract:  Pediatric heart transplant recipients have been shown to have reduced exercise performance. Studies of adult heart transplant recipients demonstrate improved endurance from regular aerobic exercise; however, this strategy has not been studied in children. We hypothesized that regular aerobic/strength training would improve exercise performance in children post-heart transplant. After an initial training session, an exercise protocol was performed at home for 12 wk, three days/wk. Aerobic exercise consisted of either running or use of an exercise bicycle to an established target HR for ≥20 min of a 30-min session for three days/wk. Subjects wore a HR monitor and kept a diary to monitor compliance. Two days/wk, strength training was performed with elastic bands to specifically exercise biceps and triceps groups for 15–20 min/session. Aerobic exercise capacity was assessed at baseline and post-training using the standard Bruce treadmill protocol. Strength was measured at baseline and post-intervention by dynamometer. Exercise and strength parameters at baseline and post-intervention were compared using paired student t- tests. Eleven subjects completed the 12-wk program, eight females and three males. The mean age at enrollment was 14.7 ± 5.3 yr (8–25) and mean time from transplant was 5.26 ± 5.34 yr (0.58–14.71). Endurance time and peak oxygen consumption improved significantly post-exercise; there was no difference in peak HR or systolic blood pressure. Strength improved in the triceps, quadriceps, and biceps groups. After a 12-wk inhome exercise intervention, pediatric heart recipients had improved exercise endurance and strength. The protocol was safe and implemented at relatively low cost. Further study is warranted to determine if the intervention can be extended to more children and whether benefits after such a short-term intervention can be sustained.