A morning and evening stroll could cut your risk of bowel cancer – here’s why

The timing of peak activity throughout the day could play a crucial role in preventing cancer risks. Photo / 123rf
Researchers have found two daily peaks in activity could cut the chances of developing the disease by a tenth.
A stroll in the morning and during the night could cut the risk of bowel cancer, research suggests.
“Intriguing” findings in the study of more than 85,000 British adults also suggested that the timing of activity could make a significant difference to its impact.
Many studies have found a strong link between exercise and cancer prevention. But the new research on bowel cancer comes amid emerging evidence that finding the right time of day can add to the benefits.
The study, led by experts from Regensburg University, used data from the UK Biobank to assess 86,252 people aged 42 to 79, who tracked physical activity by wearing a device on their wrist known as an accelerometer.
Some 529 cases of bowel cancer occurred over a follow-up period of 5.3 years.
Researchers highlighted four activity patterns: continuous day-long activity, activity late in the day, activity in the morning and evening, and activity at midday and during the night.
They found two daily peaks in activity, at around 8am and 6pm, were “associated with reduced colorectal cancer risk, beyond the benefits of overall physical activity”. The activity could cut the cancer risk by a 10th, they found.
Bowel cancer – also known as colorectal cancer – can develop anywhere in the large bowel, which includes the colon and rectum.
It is the fourth most common cancer in the UK, with an estimated 44,000 people each year – or about 120 a day – diagnosed with the disease.
Professor Dr Michael Leitzmann, chairman of the Department of Epidemiology and Preventive Medicine at the University of Regensburg in Germany, was the lead investigator for the study, published in BMC Medicine.
He said: “Our study highlights that not only is physical activity important for reducing colorectal cancer risk, but the timing of peak activity throughout the day could play a crucial role.
“By identifying specific times – early morning and late day – when physical activity is most beneficial, our findings open new avenues for targeted prevention strategies.
“If confirmed by future research, this could provide a simple yet impactful way for individuals to further reduce their cancer risk through the timing of their exercise.”
Dr Helen Croker, assistant director of research and policy at the World Cancer Research Fund, which funded the study, added: “Being physically active is one of our cancer prevention recommendations, and we know that this cuts cancer risk.
“These intriguing new findings offer potential for developing more specific recommendations, including patterns and timing of physical activity, for reducing cancer risk.”
The study did not examine why timing had such an impact.
However previous studies in 2020 found that early morning exercise could reduce the risk of breast cancer and prostate cancer.
Experts said morning exercise could reset the body clock, reducing the risk of circadian rhythm disruption, which has been linked to increased risk of disease.
Other studies have found that exercise at lunchtime and afternoons is associated with lower mortality overall, including that from heart causes.
Research has also found that consistency of exercise timing can bring health benefits. Scientists have said that exercising at the same time of day helps to keep the circadian rhythm from being disrupted.
A study of men with Type 2 diabetes found that high-intensity training in the afternoon improves blood sugar, whereas doing the same regime in the morning led to a worsening of it.