Additional cardiovascular fitness when progressing from moderate- to high-intensity exercise training in previously trained breast cancer survivors.

PURPOSE

Cardiovascular disease, often secondary to chemotherapy, is the leading cause of death in BC survivors. Increased aerobic capacity improves post-rehabilitation survival; however, many cancer rehabilitation programs are limited to lower intensity training. High-intensity interval training (HIIT) is associated with the largest improvements in aerobic capacity; therefore, this study aimed to determine whether HIIT would cause a greater increase in VOpeak than continuous moderate-intensity (MICT) exercise in previously trained BC survivors.

METHODS

Twenty BC survivors who had completed a low/moderate-intensity exercise rehabilitation program performed a VOpeak test and received a dual-energy X-ray absorptiometry (DXA) scan at baseline and after randomization into a 12-week HIIT or MICT program. ANOVA with repeated measures determined the effects of the different training programs on aerobic capacity and body composition.

RESULTS

Both groups began the training program near or above age- and sex-matched VOpeak norms. Pre- to post-intervention improvements in VOpeak (P = 0.006) and waist circumference (P = 0.007) were found in both groups; however, there were no between-group differences. Minute ventilation and peak workload increased in the HIIT group (P < 0.05) but not the MICT group. Body composition was not different after either training program.

CONCLUSIONS

These data suggest that transitioning from low/moderate-intensity exercise to moderate/high-intensity exercise causes further clinically relevant increases in VOpeak in previously trained BC survivors. HIIT did not cause a significantly greater improvement in VOpeak than MICT; however, future studies with greater intensity and frequency of training are encouraged.