Upper limb strength deficits are frequently observed following breast cancer and its treatments. It is currently unknown whether these unilateral deficits can be corrected by a standard bilateral strength training intervention. Twenty three survivors of breast cancer were included in this analysis. Fourteen performed a 16 week resistance training (RT) intervention, 9 were assigned to a usual care waitlist control group. Electromyographic (EMG) analysis of the pectoralis major and triceps brachii were monitored during three maximal isometric contractions and a fatiguing endurance task. Muscular strength was significantly different between limbs at the start of the intervention (p = 0.02). EMG amplitude and median frequency did not differ between limbs at the start of the intervention. Muscular strength was significantly different between limbs in the RT group at the end of the intervention (p = 0.01). EMG amplitude did not differ between limbs or groups at the end of the intervention. Bilateral strength training did not correct the unilateral strength deficit observed in this group of survivors of breast cancer. Periods of unilateral strength training should be implemented into periodised RT programs in this cohort.