Following diagnosis and treatment, many breast cancer survivors experience an adverse event called lymphedema. Characterized by swelling in the extremities, lymphedema occurs as a result of fluid draining from the plasma into the spaces surrounding cells. This fluid, known as lymph, can contain white blood cells and nutrients but can also include harmful substances and debris. Breast cancer can cause lymphedema, and specific treatments, like radiation or chemotherapy, can also induce this condition. While lymphedema can arise at varying degrees of severity, it often impairs mobility and reduces activity levels.
Since exercise generally has beneficial effects on breast cancer survivors, a team of researchers wondered if resistance training could also influence lymphedema. Their report of the study, recently published in JAMA Network Open, investigated the connections between intense physical activity and lymphedema.
The study recruited 115 women with an average age of 54 years. At study initiation, 15 women had lymphedema, and notably, none of these cases worsened throughout the study. Participants in the study underwent dose-escalated resistance training three times a week for a period of three months. Workouts included exercises like squats, planks, rows, shoulder presses, and dumbbell curls.
Over the three-month exercise period, bilateral arm lean mass increased compared to baseline. In addition, the edema index, calculated as a ratio of extracellular water to total body water, improved in all patients undergoing the resistance training regimen. These findings suggest that resistance training reduces extracellular water, which can lead to discomfort, and enhances fluid balance.
The study concludes that intense resistance training did not worsen symptoms associated with lymphedema. In addition, the observed improvements in fluid balance and lean mass in the arms provide strong support for including intense resistance training in breast cancer treatment plans. Further, educating breast cancer survivors, particularly those prone to lymphedema, could prove very beneficial for survivorship.
Importantly, these findings contrast with historically cautious recommendations based on the fear that intense exercise, such as resistance training, could exacerbate lymphedema. The study highlights the importance of these findings and underscores the potential for shifting our understanding of the association between physical activity and lymphedema.
Sources: JAMA Netw Open, J Strength Cond Res
