Strength and Stamina: The Dynamic Duo for Mid-Life Cancer Risk Reduction

This feels particularly personal right now, with a good friend having recently been diagnosed with stage 4 cancer. Seeing how quickly he deteriorated and acknowledging the long road ahead, it really is a horrible illness that I’m sure we all want to do everything to prevent. It was encouraging to come across 2 pieces of research this week that I think should be must reads for everyone, but particularly those of us in middle age.

The first piece of research was conducted by a team from multiple universities around the world. We’ll call this the Bettariga team. Their study aimed to examine the association between muscle strength and cardiorespiratory fitness (CRF) with all-cause and cancer-specific mortality in patients diagnosed with cancer. They also wanted to determine if these associations were affected by the type and/or stage of cancer. Specifically, they hypothesised that higher levels of muscle strength and CRF would be associated with a lower risk of mortality in cancer patients. They also investigated whether these physical fitness components were associated with a lower risk of mortality in different cancer types or stages.

The second research team (again from multiple universities) who we’ll call the Bohmann team explored the individual and joint associations of waist circumference and physical activity with cancer risk. Their hypothesis was that adherence to both WHO guidelines for waist circumference and physical activity is essential for cancer prevention and that meeting just one of these guidelines is insufficient. They sought to determine whether individuals with abdominal obesity could decrease their cancer risk by being physically active, and whether physically inactive individuals have lower cancer risk if they are abdominally lean.

The two research studies explored different aspects of physical fitness and cancer risk, and their findings can be summarised as follows:

First Research Study (Bettariga)

The study found that higher muscle strength and cardiorespiratory fitness (CRF) were significantly associated with a lower risk of all-cause mortality in cancer patients.

Specifically, cancer patients with high muscle strength had a 31% reduced risk of all-cause mortality compared to those with low muscle strength. Similarly, each unit increment in muscle strength was associated with an 11% reduction in all-cause mortality risk.

Patients with high CRF levels experienced a 46% reduced risk of all-cause mortality compared to those with low CRF levels.

When looking at cancer stage, muscle strength and CRF were significant predictors of all-cause mortality, particularly in patients with advanced cancer. For instance, in studies with a large proportion of patients with advanced cancer, high muscle strength was associated with a 23-46% reduced risk of all-cause mortality. Similarly, unit increments in muscle strength were associated with an 8-20% reduction in mortality risk in advanced cancer patients.

The study concluded that assessing muscle strength and CRF is crucial for predicting mortality in cancer patients. They also suggested that implementing tailored exercise prescriptions to enhance these physical fitness components throughout the cancer continuum may help reduce cancer-related mortality.

Second Research Study (Bohmann)

This study revealed that not meeting WHO guidelines for waist circumference and physical activity was associated with an increased risk of cancer. Participants not meeting the WHO guideline for waist circumference had an 11% increased risk of cancer, even when sufficiently physically active.

Similarly, individuals not meeting the WHO guideline for physical activity showed a 4% increased risk even if they were abdominally lean.

Not adhering to either guideline yielded the strongest increase in risk, with a 15% increase in cancer risk.

The researchers estimated that abdominal obesity coupled with insufficient physical activity could account for 2.0% of UK Biobank cancer cases. When focusing on obesity and physical inactivity related cancers, this figure rose to 6.1%.

When stratifying by sex, the combined risk of abdominal obesity and insufficient physical activity was greater for women than men. Women with both risk factors had a 25% increased risk while men had an 8% increased risk.

The authors concluded that adherence to both WHO guidelines for waist circumference and physical activity is essential for cancer prevention. Meeting just one of these guidelines was insufficient

What does this mean for us mid life athletes?

I’ve tried to distill both research studies into some key takeaways:

1. The Importance of Both Muscle Strength and Cardiorespiratory Fitness (CRF)

The research by Bettariga highlights that both muscle strength and CRF are significant factors in reducing mortality risk for cancer patients. Higher levels of muscle strength are associated with a reduced risk of all-cause mortality. This suggests that incorporating strength training into an exercise routine is crucial. Similarly, higher CRF levels are also linked to a lower risk of all-cause mortality and cancer-specific mortality. This underscores the importance of activities that improve cardiovascular health, such as running, swimming or cycling. Mid life athletes should not focus on one aspect of fitness at the expense of the other.

2. The Impact of Advanced Cancer

Bettariga’s findings show that muscle strength and CRF are particularly important for those with advanced cancer. While this might not be immediately relevant to healthy mid-life athletes, it highlights the protective effect of physical fitness as people age and potentially face health challenges. Maintaining both strength and CRF through exercise could play a role in mitigating the risk of mortality if diagnosed with cancer at a later stage of life.

3. The Significance of Waist Circumference and Physical Activity

The study by Bohmann demonstrates that meeting both WHO guidelines for waist circumference and physical activity is essential for cancer prevention. It's not enough to be physically active if you have abdominal obesity, or to have a lean waistline if you’re not physically active.

Abdominal obesity, indicated by a waist circumference above 88 cm for women and 102 cm for men, increases cancer risk, even in individuals who are sufficiently physically active. Therefore, mid-life athletes should not only exercise, but should also aim to maintain a healthy waist circumference and I would suggest a healthy overall body composition.

4. Combined Approach

Both studies underscore that a holistic approach to health is more beneficial than focusing on isolated aspects of fitness. Mid life athletes should aim for a well-rounded exercise plan that includes both strength and cardio, while also maintaining a healthy waist circumference.

In summary, these studies confirm that we can benefit from maintaining a well-rounded fitness regimen that includes both strength training and cardiorespiratory exercise, while also ensuring we maintain a healthy waist circumference and healthy body composition in line with WHO guidelines. If we take these steps, we can give ourselves the best shot at cancer prevention and even if we are unlucky enough to get diagnosed we have at least given ourselves a decent opportunity to successfully fight it.