Walking the Walk

The results of a large-scale study suggest the health benefits of walking are not just about how much you walk – how fast you walk matters too, underlining the importance of incorporating walking into comprehensive cancer-prevention strategies.

“Our study provides new evidence that a faster walking speed is associated with a reduced risk of developing any cancer and lung cancer, independently of physical activity level and grip strength,” said research team leader Professor Cheung Ching-lung, Associate Professor in the Department of Pharmacology and Pharmacy at HKUMed.

“We are also the first to show that C-reactive protein, white blood cell count, total cholesterol, low-density lipoprotein cholesterol, and glucose levels together mediated around one-fourth of the association between walking speed and cancer risk.”

The study utilised two prospective cohorts: one from a Hong Kong Osteoporosis Study (HKOS) and the other from the UK Biobank. UK participants (in the age range of 37–73) self-reported their own walking pace, while those in Hong Kong (in the age range of 27–96) underwent a timed six-metre walking test. The findings showed that fast walkers in Hong Kong had a 45 per cent lower overall risk of developing cancer while those in the UK had a 13 per cent decrease.

Several factors may be contributing to the discrepancy between the two risk percentages for the UK and Hong Kong, including: the difference in age range of the participants; the fact that one group were self-reporting and the other being objectively measured; and differences in ethnicity and lifestyle.

The most significant drop was observed in lung cancer, with risk falling by up to 53 per cent in the UK cohort, suggesting that faster walking may help protect the respiratory system and reduce cancer risk.

For the UK Biobank, walking speed was assessed using a self-reported question: How would you describe your usual walking pace? Participants were provided with three options: ‘slow’, ‘steady/average’, or ‘brisk’, which correspond to walking speeds of below 3 miles per hour (mph) or 1.34 metres per second (m/s); 3–4 mph or 1.34–1.79 m/s; and above 4 mph or 1.79 m/s, respectively.

Timed walk

In the HKOS, a timed six-metre walk test was performed during the in-person assessments between 2015 and 2019. Participants were instructed to walk along a six-metre straight line at a comfortable pace. Walking speed (in m/s) was then calculated by dividing the distance by the time walked. Previous studies have focussed mainly on the relationship between walking duration and frequency with cancer incidence and mortality, and so have measured walking over longer distances. Since this study was specifically looking at speed, they used the timed six-metre walk test which is a standard, validated method to objectively measure usual (habitual or normal) walking speed – not maximal effort, endurance, or cardiovascular response like heart rate elevation. “It’s specifically designed as a brief, reliable proxy for overall gait speed and physical function, rather than a prolonged exercise challenge,” said Professor Cheung.

In defining what constitutes a fast walking speed, he explained that a speed of 1.2 m/s – equivalent to approximately 4.32 kilometres per hour (km/h) – is associated with the lowest observed risk of cancer, beyond which further increases in speed show limited additional benefit. “For context, conventional jogging speeds typically range from 6.44 to 9.66 km/h (with a midpoint of about 8 km/h), meaning 1.2 m/s is roughly half the speed of moderate jogging,” he said.

While confirming that the results would likely apply to other forms of exercise, such as swimming or running, provided the exercise effectively trains major muscle groups, the team chose to concentrate on walking as the most convenient exercise option since it requires no special equipment or specific venue.

Muscle health

“Walking speed is a key parameter reflecting muscle health. Thus, we aimed to evaluate if walking speed can predict cancer risk,” said Professor Cheung. “Skeletal muscle plays a crucial role in regulating inflammatory and metabolic pathways. Sarcopenia, for example, is linked to chronic inflammation and dysfunction of lipid and glucose metabolism. These dysregulations are known to contribute to cancer progression.”

The ideal next step for this line of research would be to conduct a well-designed clinical trial with an exercise intervention, he said. However, such trials are challenging to implement. “Interventional studies involving physical activity are not only resource-intensive and costly, but also difficult to execute due to the challenge of achieving and sustaining meaningful changes in participants’ exercise habits and adherence over time,” said Professor Cheung. “Nevertheless, our observational findings offer supportive evidence that a simple, accessible modification – increasing habitual walking speed – may help reduce cancer risk without requiring major lifestyle overhauls or specialised facilities.”

In conclusion, Professor Cheung made a suggestion: “If you come across this article, consider taking it as a gentle nudge to make positive changes in your lifestyle. Adjusting exercise habits can be challenging and takes time, but it’s never too late to start. The benefits begin the moment you take that first step – so why not begin today?”