“Knockout Cancer”: The Impact of Adapted Boxing Training on Quality of Life in Breast Cancer Survivors, a Case Study

Background: Exercise oncology research supports multicomponent interventions as complementary therapies to improve quality of life in breast cancer (BC) survivors. Nonetheless, evidence on sport-specific, engaging approaches, such as boxing-based concurrent training, remains scarce. Method: This case study aimed to evaluate the feasibility and safety, and to explore the effects of a 16-week adapted boxing protocol. Two BC survivors with a history of triple-negative BC in treatment were enrolled. The protocol integrated aerobic, strength/power, coordination, balance and boxing-specific exercises through individually adapted, progressive sessions performed twice a week. Outcomes were assessed pre- and post-intervention and included: (I) compliance and adverse event related to the protocol, (II) functional tests (handgrip, single leg stance, 30 s sit-to-stand, trunk/shoulder mobility tests, VO2max); (III) body composition parameters (fat mass, fat-free mass,); and (IV) validated questionnaires (EORTC QLQ-C30, FA12, PSQI, BIS, HADS, IPAQ). Results: Compliance was high and no serious adverse events were detected. Sit-to-stand performance, as well as VO2max and mobility/balance, improved in both patients after the intervention. Participant A showed a favorable body modulation. Participant B, on the other hand, reported a stable weight. Participant A reported large improvements across QLQ-C30 domains, while participant B exhibited mixed results, with improved emotional functioning and pain but declines in cognitive/social functioning. Conclusions: The boxing-based concurrent training protocol was feasible, safe, and well-tolerated. Despite the limitation of the case study, the observed functional and psychosocial positive changes highlight the need for adequately larger controlled trials to clarify the training protocol efficacy in order to optimize this exercise approach in BC survivors.