A new comprehensive study reveals that muscle strength and cardiorespiratory fitness play a crucial role in reducing the risk of death for individuals battling cancer. The findings, published in the British Journal of Sports Medicine, suggest that maintaining a good level of physical fitness could be a powerful tool in the fight against this deadly disease.
The Power of Physical Fitness in Cancer Survival
The research, a meta-analysis of 42 studies involving nearly 47,000 cancer patients, found that those with higher muscle strength and cardiorespiratory fitness had a significantly lower risk of dying from any cause compared to those with lower fitness levels. Specifically, patients with high levels of both were 31% to 46% less likely to die than those with low levels of both.
Key Findings of the Study
- Reduced All-Cause Mortality: Cancer patients with high muscle strength and cardiorespiratory fitness saw a 31% to 46% reduction in the risk of death from any cause compared to those with low fitness levels.
- Incremental Benefits: Each unit increase in muscle strength was associated with an additional 11% reduction in the risk of death. Similarly, each unit increase in fitness level was linked to an 18% lower risk of death from cancer.
- Advanced Cancer: The combined effect of strength and fitness resulted in an 8% to 46% lower risk of death from any cause in patients with advanced cancer (stages three and four)
- Specific Cancers: Patients with lung or digestive cancers experienced a 19% to 41% reduction in the risk of death from any cause with a combination of strength and fitness.
- Cancer Specific Mortality: Increases in cardiorespiratory fitness (CRF) were associated with a reduced risk of cancer-specific mortality.
These results emphasize the importance of assessing muscle strength and cardiorespiratory fitness in clinical practice to determine mortality risk in cancer patients, especially those with advanced cancer.
The Importance of Muscle Strength
The study highlights the critical role of muscle strength in cancer survival. Muscle strength was primarily assessed using handgrip strength, a key indicator of overall physical health. In many studies, low strength was categorized as grip strength below 13 kg to 25.1kg in women and below 20 kg to 40 kg in men.
Muscle Strength and Survival
- Higher muscle strength was linked to a 31% reduced risk of all-cause mortality in cancer patients.
- For advanced cancer patients, higher muscle strength was associated with up to a 46% lower risk of all-cause mortality.
- The positive association between muscle strength and survival was especially significant in patients with lung and digestive cancers.
Cardiorespiratory Fitness and its Impact
Cardiorespiratory fitness, often measured through VO2max readings or walking tests, is another significant factor in improving survival rates in cancer patients.
Cardiorespiratory Fitness and Survival
- High cardiorespiratory fitness was linked to a 46% reduction in the risk of death from all causes.
- Lung cancer patients, in particular, showed a significant survival benefit from high levels of cardiorespiratory fitness, with a 31% reduced risk of death.
The Mechanisms Behind the Benefits
While the study doesn’t pinpoint exact mechanisms, it’s likely that several factors contribute to the positive effects of muscle strength and cardiorespiratory fitness in cancer patients.
- Reduced Inflammation: Physical fitness helps reduce inflammation, a factor often linked to cancer progression.
- Healthy Body Weight: Maintaining physical activity assists in maintaining a healthy weight and muscle mass, both crucial for overall health.
- Improved Metabolism: Muscle is associated with a healthier metabolism, which can positively impact cancer outcomes.
- Enhanced Circulation: Exercise improves systemic circulation, ensuring better delivery of nutrients and oxygen throughout the body.
- Reduced Risk of Other Diseases: Fitness can lower the risk of type 2 diabetes, and cardiovascular disease, which often complicate cancer treatment and survival.
Exercise Before and After Diagnosis
Research suggests that physical activity before a cancer diagnosis also plays a significant role in reducing the risk of cancer progression and mortality.
Pre-Diagnosis Physical Activity
- Individuals who engaged in low levels of physical activity before their diagnosis had a 16% reduced risk of disease progression compared to those with no recorded physical activity.
- Those with moderate to high levels of physical activity saw a 27% reduction in risk of progression.
- The risk of death from any cause was reduced by 33% in those with low physical activity and by 47% in those with moderate to high levels of physical activity before their diagnosis.
- Even relatively low levels of physical activity have shown to be advantageous.
Even after a cancer diagnosis, engaging in regular physical activity can have profound benefits.
Post-Diagnosis Physical Activity
- Cancer survivors who are physically active have a lower risk of cancer recurrence and improved survival compared to those who are not active.
- Exercise can improve cardiovascular fitness, muscle strength, body composition, reduce fatigue, anxiety, and depression, and improve overall quality of life.
Implications for Cancer Care
The study’s findings underscore the need for tailored exercise prescriptions to enhance muscle strength and cardiorespiratory fitness in cancer patients.
Recommendations
- Assess Fitness: Healthcare providers should assess fitness levels, including muscle strength and cardiorespiratory fitness, to evaluate the mortality risk of cancer patients.
- Encourage Physical Activity: Clinicians should actively promote physical activity, including muscle-strengthening exercises and cardio, as part of cancer treatment and survivorship plans.
- Individualized Exercise: Tailored exercise programs should be developed to address the specific needs and capabilities of each cancer patient.
- Community-Based Programs: Implementing community-based physical activity programs can improve access to exercise for all cancer survivors.
Looking Ahead
As cancer diagnoses continue to rise, with an estimated half a million more people living with cancer in 2025 compared to 2020, the focus on physical activity and muscle strength becomes even more important. The findings from these studies provide hope and direction for improving the outcomes for those affected by cancer. By prioritizing physical fitness, patients can actively take part in their treatment, leading to better survival rates and enhanced quality of life.
