Recreational physical activity during adolescence may play a crucial role in shaping breast tissue composition and potentially reducing future breast cancer risk, according to a new study.

The research, published in the journal Breast Cancer Research, found that teenage girls who engaged in regular recreational physical activity had lower water content in their breast tissue — a marker associated with lower breast density — along with reduced levels of stress-related biomarkers. Lower breast density has long been linked to a decreased risk of developing breast cancer.

Researchers said adolescence is a critical period for breast development, and lifestyle habits formed during this stage can influence biological pathways related to cancer risk later in life.

Highlighting the significance of the findings, lead author Rebecca Kehm, assistant professor of epidemiology at Columbia University’s School of Public Health, noted that breast cancer incidence among young women is rising while recreational physical activity among adolescents remains alarmingly low.

“The importance and urgency of this research are underscored by the rising incidence of breast cancer in young women and the alarmingly low levels of recreational physical activity observed both in this study and among adolescents across the United States and globally,” Kehm said.

The study adds to growing evidence that promoting physical activity during teenage years may offer long-term protective benefits against breast cancer, underscoring the need for public health initiatives encouraging active lifestyles among adolescents.