The impact of prescribed versus achieved resistance training intensity on strength, body composition, and psychological health in women survivors of breast cancer: Protocol for the EFICAN 2.0 randomized trial.

BACKGROUND

Strength training (ST) is recommended for survivors of breast cancer due to its health-related benefits. However, the optimal method for prescribing ST intensity in this population remains unexplored.

OBJECTIVE

To compare the effects of three intensity prescription methods on muscular strength, body composition, physical function and psychological health in survivors of breast cancer; and to examine how the training intensity progresses over time according to each method.

METHODS

A three-arm randomized trial will be conducted with 60 women survivors of breast cancer randomly allocated to: (1) daily estimated one-repetition maximum (1RM) using individual load-velocity relationship; (2) initial 1RM estimation via load-velocity relationship, without daily updates; or (3) initial 1RM estimation via a 10RM test, without daily updates. The intervention includes a 2-week familiarization phase and an 8-week intervention phase. Training intensity will be prescribed between 60 and 75% 1RM, following the American College of Sports Medicine guidelines. Primary outcomes include muscle strength, physical function, cardiorespiratory fitness, fatigue, pain, quality of life, anxiety, and depressive symptoms. The secondary outcome is the difference between prescribed and achieved training intensity, which will be continuously monitored in all groups using a linear velocity transducer, and analyzed over time. Adherence, adverse events, and deviations from the protocol will be recorded.

CONCLUSION

This trial will provide novel insights into the effects of different ST intensity prescription methods on physical and psychological outcomes in survivors of breast cancer. It will also determine whether traditional approaches achieve intended training intensities, thereby advancing knowledge on exercise prescription in oncology.