The purpose of this article is to determine the effectiveness of exercise interventions to improve body composition, quality of life, bone mineral density, mental health outcomes, cardiovascular outcomes, fatigue, and physical activity levels in young women with breast cancer. A systematic review of randomized controlled trials was performed using Embase, Ovid MEDLINE, PsycINFO, and The Cumulative Index to Nursing and Allied Health Literature. Participants were young women (aged 18–55 years) diagnosed with BC. Eight trials met the inclusion criteria and were assessed using the Cochrane risk of bias tool by two reviewers. Meta-analyses found no significant changes on body composition. Narrative analyses demonstrated inconsistent findings of exercise on bone mineral density, fatigue, and psychosocial outcomes. Positive effects were found for quality of life, cardiovascular outcomes, and physical activity levels. Firm conclusions could not be drawn due to the high heterogeneity, low quality, and limited number of articles available using this population. This suggests that further research is needed to address the impact of exercise on the side effects of breast cancer in young women.