Harnessing Exercise: The Dual Benefits of Weights and HIIT for Cancer Recovery

A 12-week supervised exercise intervention—whether resistance training or high-intensity interval training—can increase circulating myokines with known anti-tumor properties and suppress breast cancer cell growth in vitro, according to a randomized trial published in Medicine & Science in Sports & Exercise.

The study enrolled 28 breast cancer survivors (mean age 55.5 ± 8.8 years) who were at least one year post-diagnosis. Participants were randomized to complete either resistance training (RT) or high-intensity interval training (HIIT), three times per week over 12 weeks, under supervision. Fasting blood samples were collected at baseline and after the final session (with a minimum 48-hour washout) to assess serum myokine concentrations and their effects on triple-negative breast cancer cells.

Both exercise modalities significantly reduced in vitro growth of MDA-MB-231 cells—by 22% in the RT group and 25% in the HIIT group—compared to pre-intervention levels. The difference between exercise types was not statistically significant.

Notably, specific myokines responded preferentially to the type of exercise. Resistance training significantly elevated serum levels of secreted protein acidic and rich in cysteine (SPARC), while HIIT increased oncostatin M (OSM). Both proteins have been implicated in the regulation of tumor proliferation, angiogenesis, and immune signaling, although their exact mechanisms in cancer suppression remain under investigation.

Importantly, the suppressive effect of HIIT on tumor cell growth was associated with favorable changes in body composition, including increased lean mass and reduced fat mass—findings that echo previous observations of the metabolic contribution to cancer control. However, these associations were not observed in the resistance training group, suggesting modality-specific mechanisms may be at play.

The MDA-MB-231 cell line used in the study is a well-established model for triple-negative breast cancer, which lacks estrogen, progesterone, and HER2 receptors and is often more aggressive and treatment-resistant. While the in vitro results are encouraging, the authors acknowledged limitations, including the small sample size and use of surrogate endpoints. The study did not assess whether myokine-induced tumor suppression translates into reduced recurrence or improved clinical outcomes in vivo.

Nonetheless, the findings reinforce a growing body of literature suggesting that physical activity exerts immunomodulatory and tumor-inhibitory effects independent of traditional risk factors. Prior work by the same research group has shown that even a single bout of resistance or interval training can acutely increase circulating anti-cancer myokines and reduce tumor cell viability in vitro.

Taken together, these results highlight the role of structured exercise as a potential adjunct to cancer survivorship care—one that is both accessible and adaptable. Clinicians may consider incorporating either RT or HIIT into rehabilitation protocols, tailoring recommendations based on patient preference, tolerance, and comorbidities.

Further research is needed to elucidate the long-term clinical impact of exercise-induced myokine changes and to determine whether these molecular signals mediate tangible benefits in disease-free survival. But in the interim, the message is clear: movement matters—and it may matter more than previously understood.