Combined exercise: a winning strategy for post–breast cancer cardiorespiratory fitness

  Breast cancer, although increasingly well treated, still exposes patients to a higher risk of treatment-related cardiovascular toxicity. This toxicity can lead to a significant decline in cardiorespiratory fitness (CRF), a core component of overall health that is closely linked to cardiovascular and all-cause mortality. Despite growing interest in the benefits of physical activity among survivors, until now there had been no clear recommendation identifying which type of exercise is most effective for improving CRF.   This systematic review with a Bayesian network meta-analysis therefore aimed to compare the efficacy of 12 different exercise modalities in order to identify the optimal protocol for women who have survived breast cancer.   Understanding better to prescribe better   Rigorous methodology: The analysis included 41 randomized controlled trials involving 2,606 participants. The authors used advanced Bayesian statistical methods to estimate mean differences (MD) in VO₂max, the gold standard measure of CRF.   Interventions were categorized by intensity, frequency, duration, modality (continuous vs interval), and whether or not they were combined with resistance training.   The most effective exercise types compared with usual care were:  

• Moderate-to-vigorous aerobic training (M–V): significant improvement in CRF (MD: +3.4; 95% CrI: 1.9–5.0; high certainty).
• High-intensity interval training (HIIT): significant improvement (MD: +2.9; 95% CrI: 1.2–4.6; low certainty).
• Moderate-intensity continuous training (MICT): modest improvement (MD: +1.6; 95% CrI: 0.13–3.1; low certainty).
• Combined exercise (M–V + RE): moderate-to-vigorous cardio plus resistance exercise, yielding the largest improvement (MD: +4.3; 95% CrI: 2.5–6.1; moderate certainty).

  In addition, M–V + RE significantly outperformed MICT (MD: +2.7; 95% CrI: 0.4–5.0), highlighting the value of a mixed program.   The SUCRA ranking (Surface Under the Cumulative Ranking Curve) placed M–V + RE first (88.15%), followed by HIIT + MICT (79.69%), then M–V alone (76.48%).   Finally, the timing of exercise initiation (during vs after treatment) did not significantly influence outcomes, suggesting exercise is beneficial regardless of when it is implemented.   Notable limitations  

• Limited direct head-to-head comparisons between exercise types
• Often modest sample sizes
• No in-depth analysis of adverse effects or adherence

  Research perspectives   Future work should focus on larger randomized trials directly comparing exercise modalities, while also addressing safety, tolerability, and real-world clinical feasibility. It will also be essential to incorporate patient preferences, fatigue levels, and personal constraints into exercise prescription.