Effects of Resistance Training at Different Intensities on Preventing Breast Cancer-Related Lymphedema: A 1-Year Randomized Controlled Trial.

[BACKGROUND] Breast cancer-related lymphedema (BCRL) is a relatively common and harmful complication after breast cancer surgery, and there is currently no effective cure. We hypothesized that, compared with the control group, 12 weeks of resistance exercise at different intensities could reduce the incidence of BCRL after axillary lymph node dissection.

[METHODS] 114 breast cancer patients undergoing axillary lymph node dissection were randomly divided into a Control Group (CG), a Low-to-Moderate Intensity Exercise Group (L-MIEG, 40%-70% 1-RM) and a Moderate-to-High Intensity Exercise Group (M-HIEG, 60%-85% 1-RM).

[RESULTS] (1) The 12-month cumulative BCRL incidence was higher in the CG (16.3%, 6/37) than in the L-MIEG (8.3%, 3/36) and M-HIEG (5.5%, 2/37). (2) Postintervention and at 6-and 12- month follow-ups, both intervention groups had smaller interlimb differences than the CG (P < .05), and the M-HIEG had smaller differences at 6-month than the L-MIEG (P < .05). (3) InBody analysis showed both intervention groups outperformed CG in segmental water differences, extracellular water (ECW), and single-frequency bioelectrical impedance analysis (SFBIA) (P < .05), and the M-HIEG was better at 6-month (P < .05). (4) At 6-and 12-month follow-ups, both intervention groups improved grip strength more than CG (P < .05), and the M-HIEG was superior at 12 months (P < .05).

[CONCLUSIONS] Different- intensity resistance exercises benefit BCRL prevention, with M-HIEG being more effective.