Introduction
Lymphedema is a persistent, often debilitating sequela of breast cancer surgery and radiation. Historically, breast cancer survivors have been cautioned to avoid heavy lifting or intense exercise, fearing exacerbation of swelling. Here is a review of two important publications on this subject.
The first is a landmark study entitled, Weight Lifting in Women with Breast-Cancer–Related Lymphedema, by Kathryn Schmitz, PhD et al. published in the New England Journal of Medicine in August 2009. The second study is entitled Resistance Training and Lymphedema in Breast Cancer Survivors, by Shamsesfandabadi et al. published in JAMA Network Open. in June 2025.
Both studies challenge the dogma of avoiding heavy lifting or intense exercise for fear of exacerbating arm lymphedema, but from slightly different perspectives and methodological approaches. Together, they contribute robust evidence supporting the integration of resistance training in survivorship care.
Study Designs and Cohorts
Schmitz et al. conducted a randomized controlled trial (RCT), the gold standard for causal inference — involving 141 breast cancer survivors with existing stable lymphedema. Participants were randomized to either a supervised, then self-managed progressive weightlifting program or a no-change control group. This pragmatic design aimed to test real-world implementation by using community fitness centers.
Conversely, Shamsesfandabadi et al. conducted a prospective cohort study without a control arm, enrolling 115 women, of whom only 13% had clinical lymphedema at baseline. The cohort underwent dose-escalated, intense resistance training three times weekly for three months. This design prioritized real-world effectiveness but lacked randomization, introducing potential confounding factors.
Thus, while both studies sought to test safety and efficacy, Schmitz et al. addressed causality more rigorously, whereas Shamsesfandabadi et al. examined the feasibility and short-term physiological changes of more intense training.
Exercise Protocols
The interventions differed notably in structure and intensity:
- Schmitz et al. used gradually progressive resistance training over a one-year period, starting with very low weights and increasing incrementally only when no symptoms worsened. Participants attended supervised sessions for 13 weeks, then continued unsupervised, with the program focusing on safe adaptation to lifting.
- Shamsesfandabadi et al. implemented dose-escalated, hypertrophy-oriented training thrice weekly for three months. The regimen included compound lifts (hex bar deadlifts, squats, presses) with linear progression, designed to achieve sufficient loading for muscle growth. Close supervision ensured adherence.
Therefore, while Schmitz et al. tested a cautious, community-friendly regimen aligned with conservative guidelines, Shamsesfandabadi et al. pushed toward an evidence-based, modern strength program more typical of athletic training, reflecting recent shifts in exercise oncology.
Outcome Measures
Both studies assessed lymphedema using objective methods but with different technologies:
- Schmitz et al. measured limb volume by water displacement — a classic, valid method — and used clinical assessments and symptom surveys.
- Shamsesfandabadi et al. used bioimpedance analysis (BIA) to quantify fluid compartments (extracellular vs. total body water), plus ultrasonography to confirm changes. This allowed fine-grained detection of fluid shifts not confounded by muscle hypertrophy, which can obscure circumference measures.
Moreover, Schmitz et al. evaluated functional strength (bench press, leg press) and self-reported symptoms over 12 months, while Shamsesfandabadi et al. focused on short-term body composition and fluid balance shifts, without long-term follow-up or patient-reported outcomes.
Findings
Impact on Lymphedema:
- Schmitz et al. found no significant increase in arm swelling in the weightlifting group versus controls. Notably, exacerbations were lower in the weightlifting group (14% vs 29%). Arm symptoms such as heaviness and pain decreased, with participants reporting improved daily function.
- Shamsesfandabadi et al. found no cases of subjective or clinical worsening. Objectively, the edema index (ECW/TBW ratio) decreased significantly, indicating a measurable reduction in fluid imbalance. This was consistent across the entire cohort, including high-risk patients with axillary lymph node dissection (ALND).
Strength and Body Composition:
Both studies demonstrated clear gains in strength and lean mass:
- Schmitz et al. reported significant improvements in upper- and lower-body strength tests, with no change in body fat.
- Shamsesfandabadi et al. observed significant increases in bilateral arm lean mass and total body water, signifying effective muscle hypertrophy. A mild decline in body fat was also noted.
These gains were achieved safely in both protocols, highlighting the feasibility of resistance training for functional recovery.
Clinical Relevance
The studies converge on a critical finding: Contrary to outdated guidelines, resistance training does not worsen lymphedema and may reduce symptoms and fluid accumulation. Both trials underscore that strength training is not only safe but potentially therapeutic, promoting muscle hypertrophy, fluid balance, and functional capacity.
Notably, Schmitz et al. provide stronger evidence for causality due to randomization and a longer follow-up. In contrast, Shamsesfandabadi et al. contribute modern physiological insights via BIA and show that even intense hypertrophy-focused training is safe — expanding the conversation beyond conservative rehabilitation to more ambitious fitness goals.
Limitations
Each study has constraints:
- Schmitz et al. lacked modern body composition tools like BIA, so muscle gains could obscure limb volume readings. However, its RCT design and large sample of women with confirmed lymphedema lend strong external validity.
- Shamsesfandabadi et al. did not include a control group, relied on a relatively short follow-up, and lacked patient-reported outcomes. The high adherence and robust BIA data partially compensate, but randomized trials are needed to confirm their results over longer periods.
Implications for Practice
Together, these studies provide robust support for evolving clinical guidelines. Breast cancer survivors should not be discouraged from resistance training; instead, supervised, progressive programs can be tailored for safety and therapeutic benefit. For clinicians, these findings encourage a shift away from fear-based activity restrictions toward proactive, evidence-based rehabilitation and fitness.
Schmitz et al. laid the foundation for safe, cautious weightlifting integration into community settings (e.g., the LIVESTRONG at the YMCA model). Shamsesfandabadi et al. extend this to show that properly dosed, intense strength training — resembling modern sports training — can also be appropriate, challenging survivors to aim not merely for function but for fitness and strength gains.
Conclusion
In summary, both studies reinforce a paradigm shift: resistance training is not merely safe for breast cancer survivors with or at risk for lymphedema — it may be an essential part of comprehensive survivorship care, promoting strength, fluid balance, and overall well-being. While future randomized trials should refine dosage, duration, and patient subgroups, current evidence strongly justifies moving from caution to prescription when advising exercise for this population.
References
Kathryn H. Schmitz, Ph.D., M.P.H. et al.: Weight Lifting in Women with Breast-Cancer–Related Lymphedema, N ENGL J MED 361;7 nejm.org August 13, 2009
Parisa Shamsesfandabadi, MD, et al.: Resistance Training and Lymphedema in Breast Cancer Survivors, JAMA Network Open. 2025;8(6) jamanetworkopen.2025.14765 June 11, 2025
