Resistance Training Cuts Cancer-Related Fatigue, Large Meta-Analysis Finds

A meta-analysis of 116 trials found that resistance training during breast cancer treatment cuts fatigue and boosts physical function. Adding aerobic exercise does not reduce these gains.

What the Research Found

Researchers pooled data from 116 randomized controlled trials. These trials included over 9,200 women with breast cancer. The team compared three approaches: resistance training alone, aerobic exercise alone, and combined programs.

Both resistance training and combined programs cut cancer-related fatigue compared to no exercise. The effect sizes were nearly the same. Resistance training showed a standardized mean difference of -0.52. Combined programs showed -0.47. Standardized mean difference measures how large an effect a given approach produces. These are medium-sized effects. They match noticeable gains in daily life.

Physical function improved even more. Women doing resistance or combined training scored 0.86 to 0.90 standard deviations higher than controls. That is a large effect. It reflects real change in strength and daily movement.

Does aerobic exercise interfere with strength gains? The main analyses found no major difference between resistance-only and combined programs for muscle mass or strength. A sensitivity analysis removed statistical outliers to test robustness. It did favor resistance training for lean mass and strength. But the gaps were modest.

This is strong evidence from a large, pre-registered meta-analysis. The main limit: most studies were short in duration.

What This Means for You

If you are in treatment for breast cancer, the data support exercise as a helpful add-on to standard care. Both fatigue and treatment-related weakness improved with exercise in these trials.

The interference effect — the idea that aerobic exercise blunts strength gains — does not appear to be a major concern here. If you enjoy both types of exercise, doing both is reasonable. If you only have energy for one type, resistance training showed the strongest single effect on fatigue and function.

The authors reported consistent findings across treatment phases. These include chemotherapy, radiation, and hormone therapy. Subgroup sample sizes varied.

What to Do

• Start with 2–3 resistance training sessions per week. Even bodyweight exercises or resistance bands count.
• If you have energy for aerobic exercise too, add it. Walking is a good option. The combination worked as well as resistance training alone for fatigue and function.
• Work with your oncology team to adjust intensity based on how you feel. Gradual consistency matters more than high intensity, according to clinical guidance.

Evidence strength: Based on a pre-registered meta-analysis of 116 RCTs with 9,206 participants (strong evidence).