Purpose <p>Explore the preventive effects of varying intensity progressive resistance exercise on breast cancer-related lymphedema.</p> Methods <p>A total of 114 breast cancer patients who underwent axillary lymph node dissection at Tangshan People’s Hospital from January to April 2024 were included. Participants were randomly assigned to three groups: the control group received conventional care; intervention group 1 received conventional care + low-intensity progressive resistance exercise; and intervention group 2 received routine nursing + moderate and high-intensity progressive resistance exercise. Body composition and grip strength were assessed pre-intervention, post-intervention, and at 3 and 6&#xa0;months follow-up to compare differences among the groups.</p> Results <p>(1) Body composition: At post-intervention, 3 and 6&#xa0;months follow-up, segmental water differences and extracellular water ratios, along with 1- and 5-kHz SFBIA in both intervention groups, were lower than in the control group. Intervention group 2 had a lower extracellular water ratio than group 1 at post-intervention, and at 3&#xa0;months follow-up, group 2 showed lower water differences and extracellular water ratios than group 1, with slight variations at 6&#xa0;months (<i>P</i> &lt; 0.001). (2) Grip strength: At post-intervention, 3&#xa0;months and 6&#xa0;months follow-up, grip strength in intervention group 1 and intervention group 2 was higher than that in control group, and the difference was statistically significant (<i>P</i> &lt; 0.001).</p> Conclusion <p>Resistance exercise enhances muscle strength and prevents lymphedema, with moderate-high-intensity exercise proving more effective than low intensity. Adverse events were minimal, suggesting that increasing resistance exercise intensity, while considering participants’ conditions, may yield better preventive outcomes.</p>