The Analgesic Effect of Resistance Training after Breast Cancer (ANTRAC): A Randomized Controlled Trial

Objective The objective of this blinded parallel-arm randomized controlled trial was to investigate the effect of resistance training (RT) on pain, maximal strength, and shoulder function in breast cancer survivors (BCS) with persistent pain after treatment. Methods Twenty BCS with self-reported pain ≥1.5 yr after treatment were randomized to an experimental group (EXP, n = 10), who performed a supervised progressive total body heavy RT program 2 times per week for 12 wk, or a control group (CON, n = 10), who was instructed to continue their everyday life. Perceived pain intensity, pressure pain threshold (PPT) levels, one-repetition maximum (1RM), and active range of motion were collected pre- and postintervention and at 3 months follow-up. Results There was a significant 11% decrease in peak pain intensity (P < 0.05) for both groups, a significant 48% increase in 1RM (P < 0.05), and a significant 35% increase in PPT levels (P < 0.001) for EXP, but not for CON. For EXP, maximal strength at follow-up was still significantly greater than at preintervention (P < 0.05), whereas PPT levels had reverted to baseline levels. There was no change in active range of motion (P < 0.05) and no change in arm circumference (P < 0.05). Conclusions RT had a significant effect on 1RM and PPT of BCS with persistent pain after treatment, demonstrating both a functional and analgesic effect of progressive RT in this population. Strength was largely maintained after detraining, whereas PPT levels were not, indicating that the process of RT rather than the gain in strength may be associated with analgesia.