Exercise: Even a Little is of Benefit

Tuesday, September 6, 2011 // Uncategorized

Sometimes people are daunted by the amount of exercise that is recommended:

  This study fromThe  Lancet indicates that even 15 minutes a day of exercise can have health benefits.  The first is the summary from Journal Watch followed by the abstract from The  Lancet.

Minimal Physical Activity Confers Mortality Benefit

Just 15 minutes of exercise daily lowered 8-year mortality and cancer incidence.

Current guidelines recommend 150 minutes weekly of leisure-time physical activity (LTPA) to achieve a variety of health benefits, but the benefits of less exercise are uncertain. Investigators in Taiwan studied a cohort of more than 400,000 healthy people who participated in a privately operated medical screening program during 13 years. At enrollment, patients described and quantified their LTPA levels and were grouped into five activity levels (from “inactive” to “very high volume”).

Fifty-four percent of patients were “inactive” (<60 minutes of LTPA weekly), and another 22% were “low volume” (average, 92 minutes weekly). After a mean follow-up of 8 years, compared with inactive individuals, those with low-volume activity had significantly lower mortality from all causes (hazard ratio, 0.86), all cancers (HR, 0.90), cardiovascular disease (HR, 0.81), and ischemic heart disease (HR, 0.75), and a significantly lower incidence of all cancers (HR, 0.94). Most of these health benefits increased in dose-related fashion as activity level rose.

Comment: This cohort study cannot establish causation, but an average of 15 minutes of daily exercise — half the recommended amount — was associated with significantly lower 8-year mortality and cancer incidence. Many people might find this modest level of exercise more achievable than the recommended level; its potential benefit could encourage inactive individuals to introduce some level of exercise into their daily routines.

Bruce Soloway, MD

Published in Journal Watch General Medicine September 6, 2011


Wen CP et al. Minimum amount of physical activity for reduced mortality and extended life expectancy: A prospective cohort study. Lancet 2011 Aug 16; [e-pub ahead of print]. (

The Lancet, Early Online Publication, 16 August 2011
doi:10.1016/S0140-6736(11)60749-6Cite or Link Using DOI

Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study

Original Text

Dr Chi Pang Wen MD a b Corresponding Author Email Address, Jackson Pui Man Wai PhD c †, Min Kuang Tsai MS a b, Yi Chen Yang MS a b, Ting Yuan David Cheng MS d, Meng-Chih Lee MD e, Hui Ting Chan MS a, Chwen Keng Tsao BS f, Shan Pou Tsai PhD g, Xifeng Wu MD h



The health benefits of leisure-time physical activity are well known, but whether less exercise than the recommended 150 min a week can have life expectancy benefits is unclear. We assessed the health benefits of a range of volumes of physical activity in a Taiwanese population.


In this prospective cohort study, 416 175 individuals (199 265 men and 216 910 women) participated in a standard medical screening programme in Taiwan between 1996 and 2008, with an average follow-up of 8·05 years (SD 4·21). On the basis of the amount of weekly exercise indicated in a self-administered questionnaire, participants were placed into one of five categories of exercise volumes: inactive, or low, medium, high, or very high activity. We calculated hazard ratios (HR) for mortality risks for every group compared with the inactive group, and calculated life expectancy for every group.


Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week (95% CI 71—112) or 15 min a day (SD 1·8), had a 14% reduced risk of all-cause mortality (0·86, 0·81—0·91), and had a 3 year longer life expectancy. Every additional 15 min of daily exercise beyond the minimum amount of 15 min a day further reduced all-cause mortality by 4% (95% CI 2·5—7·0) and all-cancer mortality by 1% (0·3—4·5). These benefits were applicable to all age groups and both sexes, and to those with cardiovascular disease risks. Individuals who were inactive had a 17% (HR 1·17, 95% CI 1·10—1·24) increased risk of mortality compared with individuals in the low-volume group.


15 min a day or 90 min a week of moderate-intensity exercise might be of benefit, even for individuals at risk of cardiovascular disease.


Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes.

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