Higher levels of physical activity -- regardless of intensity -- are associated with a lower risk of early death in middle aged and older people, a study claims.
The findings, published in the British Medical Journal (BMJ), also show that being sedentary, for example sitting for 9.5 hours or more a day -- excluding sleeping time -- is associated with an increased risk of death.The World Health Organization (WHO) guidelines recommend at least 150 minutes of moderate intensity or 75 minutes of vigorous physical activity each week for adults aged between 18 and 64 years.
However, these are based mainly on self-reported activity, which is often imprecise. So exactly how much activity -- and at what intensity -- is needed to protect health remains unclear.
Researchers led by Professor Ulf Ekelund at the Norwegian School of Sport Sciences in Oslo, Norway analysed observational studies assessing physical activity and sedentary time with death.
Studies included in the research used accelerometers -- a wearable device that tracks the volume and intensity of activity during waking hours -- to objectively measure daily activity levels.
Examples of light intensity activity include walking slowly or light tasks such as cooking or washing dishes. Moderate activity includes any activities that make you breath harder, such as brisk walking.
Data from eight high quality studies involved 36,383 adults aged at least 40 years with average age of 62.Activity levels were categorised into quarters, from least to most active, and participants were tracked for an average of 5.8 years. During follow-up, 2,149 (5.9%) participants died.
After adjusting for potentially influential factors, the researchers found that any level of physical activity, regardless of intensity, was associated with a substantially lower risk of death.