11 minutes of brisk walking a day could lower risk of early death

By Alexander Mok

The World Health Organization (WHO) as well as several international and local government health agencies recommend a weekly minimum of 150 minutes of moderate-intensity physical activity to maintain health. However, exactly how much is needed to achieve meaningful health benefits and appreciable population impact is unclear.

We conducted a population-level dose-response meta-analysis of large cohort studies, pooling nearly 200 studies and 100 population cohorts (totalling over 30 million adults) to examine the dose–response relationship between physical activity and several chronic disease and mortality outcomes in the general population. Using extensive data harmonisation methods to calibrate energy expenditure levels into marginal metabolic equivalent-of-task units, we were able to conduct the largest ever study of its kind.

In general, higher activity levels were linked with lower risks of death from all causes, with the greatest marginal health benefits accruing around the WHO recommended weekly minimum of 150 minutes of moderate activity. There were incrementally smaller marginal health benefits above this level up to around 300 minutes per week, beyond which additional health benefits were smaller and less certain, owing to a paucity of data and lower modelling precision for certain disease outcomes such assite-specific cancers (e.g. lung, liver, breast, and prostate cancers).

The most encouraging result was that appreciable health benefits can already be gained at levels below the current public health recommendations. For example, achieving just half the recommended level (equivalent to an 11-minute daily brisk walk) reduced the risks of early death by 23 percent, cardiovascular disease by 17 percent, and cancer by seven percent.

We modelled Population Impact Fractions (PIFs) to contextualise and translate the results for public health promotion. At the population-level, one in 10 premature deaths could have been averted if everyone had met just half (i.e. 75 minutes) the weekly target of 150 minutes. This translates to just as little as 11 minutes of daily brisk walking to reap meaningful health benefits such as longevity and lower risks of cardiovascular disease, and certain cancers.

Our findings have important implications at the individual and systems-level. Firstly, at the individual-level, it could motivate busy adults to start accumulating any increase in physical activity (as little as just over 10 minutes a day) to improve health and longevity. At the health systems level – especially in the context of Healthier SG – these dose–response associations facilitate modelling of the disease burden of physical inactivity and informs the potential impact of public health policy and community programmes for lowering the barriers and realigning population-level incentives for active living.

ABOUT DR ALEXANDER MOK