Effects of resistance training vs high intensity interval training on body composition, muscle strength, cardiorespiratory fitness, and quality of life in survivors of breast cancer: a randomized trial

Purpose Breast cancer treatments often lead to unfavourable changes in body composition, physical fitness, and quality of life (QoL). We compared the effects of resistance training (RT) and high-intensity interval training (HIIT) on these outcomes in survivors of breast cancer. Methods Twenty-eight survivors of breast cancer, post-treatment (Stage I-III), aged 55.5 +/- 8.8 years and body mass index 27.9 +/- 5 kg/m(2) were randomly allocated to a 12-week supervised RT (n = 14) or HIIT (n = 14) intervention, 3 days per week. Body composition (dual energy x-ray absorptiometry), upper and lower body muscle strength (1-repetition maximum), cardiorespiratory fitness (CRF) (Ekblom Bak Cycle Test), and QoL domains (EORTC QLQ-C30 and EORTC QLQ-BR45) were assessed at baseline and 12 weeks. Results There were no significant differences between groups at baseline. Exercise attendance ranged from 81 to 85%. Between groups, there were significant differences (p <= 0.001) after 12 weeks in chest press strength for RT (mean difference [MD] = 4.7 kg) and CRF for HIIT (MD = 1.9 ml/min/kg). Within groups, there were significant improvements (p < 0.05) for % lean mass and % fat mass in both RT and HIIT, as well as for upper and lower body muscle strength, CRF, and QoL domains. No major adverse events were noted. Conclusion Both exercise groups improved body composition, physical fitness, and QoL domains over 12 weeks of RT or HIIT, although mode-specific benefits were apparent with more substantial improvements in lean mass and muscle strength with RT and reductions in % fat mass and improved CRF with HIIT. Tailored exercise programs should address the specific health needs of each patient.