Any physical activity, even if only over 1-2 sessions per week or at lower levels than recommended, is associated with reduced mortality compared to sedentary lifestyle
EBM Focus - Volume 12, Issue 4
- Guidelines recommend adults perform at least 150 minutes of moderate physical activity or at least 75 minutes of vigorous activity during the week, but how that should be distributed throughout the week is not clear.
- A retrospective cohort study of over 63,000 adults in Great Britain categorized participants, based on their responses to an interview, as inactive (sedentary), insufficiently active (active but not meeting weekly recommendations), weekend warrior (meeting recommendations over only 1-2 sessions per week), or regularly active (meeting recommendations over ≥ 3 sessions per week).
- Compared to the inactive pattern, each of the three patterns with some activity was associated with a reduced risk of all-cause mortality, death from cardiovascular causes, and death from cancer. Randomized trials are needed to better our understanding of the influence of physical activity on health.
Recent guidelines recommend adults perform at least 150 minutes of moderate physical activity or at least 75 minutes of vigorous physical activity per week, but they do not provide strong recommendations regarding how that exercise should be distributed throughout the week (World Health Organization 2010, NICE 2014, US Department of Health and Human Services 2008). A previous observational study found that exercise spread over 3 or more sessions per week was associated with a reduced risk of death, but that the same amount of exercise spread over only 1-2 sessions was associated with a reduced risk only for men without major risk factors such as smoking or high body mass index (Am J Epidemiol 2004 Oct 1;160(7):636). To assess the association between physical activity patterns and mortality in a larger population, a recent retrospective cohort study pooled data collected from 1994 to 2012 from the Scottish Health Survey (SHS) and the Health Survey for England (HSE). In the study, 63,591 adults ≥ 40 years old (46% male, 93% white) were interviewed about physical activity patterns and medical and lifestyle history. Based on the interview, participants were categorized into one of four types of physical activity patterns: inactive (no activity) (reported in 63% of participants), insufficiently active (some activity, but not meeting weekly recommendations) (in 22%), weekend warrior (meeting recommendations in only 1-2 sessions per week) (in 4%), or regularly active (meeting recommendations in ≥ 3 sessions per week) (in 11%). Mortality was assessed for a mean follow-up of 8.8 years through The British National Health Service Central Registry. Participants who died within 2 years of the interview were excluded from the study.
Death from any cause occurred in 13.8% of participants, with 4.4% dying from cardiovascular causes and 4% dying from cancer. Compared to the inactive physical activity pattern, each of the three groups with some level of self-reported physical activity were associated with a reduced risk of all-cause mortality. The hazard ratio (adjusted for age, sex, smoking status, occupation, and long-term illness) for the regularly active pattern was 0.69 (95% CI 0.58-0.73), with similar ratios for the weekend warrior and insufficiently active patterns. Risks of death due to cardiovascular causes or cancer were also reduced. In additional analyses with the insufficiently active pattern as the reference group, the regularly active pattern had a reduced risk of all-cause mortality and death from cancer, but not of death from cardiovascular causes. The weekend warrior pattern did not have an altered risk of any mortality outcome compared to the insufficiently active pattern.
This large retrospective cohort study found that any moderate or vigorous physical activity in adults, including activity confined to 1-2 sessions per week or less than that recommended by guidelines, was associated with a reduced risk of all-cause mortality, death from cardiovascular disease, and death from cancer. However, physical activity was self-reported in response to questions from only one interview, so the categorization may not accurately reflect actual lifestyle over many years. Also, generalizability to other cultures and ethnicities may be limited, as the study used data from British population studies and 93% of the participants were white. Finally, due to the observational study design, confounders, such as the possibility that a participant’s health at the time of interview determined both physical activity and risk of death, cannot be excluded (though this limitation is somewhat mitigated by excluding participants who died within the first two years of the interview and by adjusting analyses). Randomized trials are needed to better our understanding of the health benefits of physical activity and optimal activity patterns. In the meantime, this study provides evidence to support an easy-to-understand and unambiguous association: any physical activity, even if confined to a small number of sessions per week or if less than that recommended by most guidelines, has health benefits.
See the Physical activity for cardiovascular disease prevention and Physical Activity Guidelines for Americans topics in DynaMed Plus for more information. DynaMed users click here.