New evidence reinforces why sedentary behaviour is a killer and shows that just a few minutes of exercise per day could help slash the risk of heart disease and stroke.
Researchers suggested that swapping time spent sitting down for exercise led to better cholesterol levels, helps people stay a healthy weight and leads to a smaller waist circumference.
The findings, published in the European Heart Journal and supported by the British Heart Foundation (BHF), found that when “as little as four to 12 minutes per day were reallocated (from sedentary behaviour) into moderate to vigorous physical activity” there were benefits across all such measures.
The authors said: “Conversely, a greater proportion of time spent sedentary was detrimentally associated with all outcomes.”
Examples of moderate activity can include very brisk walking (4mph or faster), heavy cleaning such as washing windows or mopping, cycling at 10-12mph, or badminton.
Vigorous activity examples are hiking, jogging at 6mph or faster, shovelling, fast cycling, a football game, basketball or tennis.
The new study included 15,253 people in five countries who wore gadgets to measure their activity levels for 24 hours a day.
The results suggested a hierarchy in what was good for health, with moderate to vigorous exercise the most beneficial, followed by light exercise, sleeping or standing.
The study also found that replacing 30 minutes of sitting per day with 30 minutes of moderate to vigorous exercise had the biggest effect on people having a lower body weight.
Modelling showed that cholesterol levels also improved when as few as six minutes of sedentary behaviour were replaced with exercise, though more exercise was better.
Blood sugar levels were also lower, according to the modelling, if people spent more time exercising, standing, or sleeping than being sedentary.
Calculations in the study suggested that, for a 54-year-old woman with an average body mass index (BMI) of 26.5, replacing 30 minutes of daily sitting or lying time with moderate or vigorous exercise could also translate into a 2.5 cm (2.7%) decrease in waist circumference and a lower BMI.
Dr Jo Blodgett, first author of the study from University College London (UCL), said: “The big takeaway from our research is that while small changes to how you move can have a positive effect on heart health, intensity of movement matters.
“The most beneficial change we observed was replacing sitting with moderate to vigorous activity – which could be a run, a brisk walk, or stair climbing – basically any activity that raises your heart rate and makes you breathe faster, even for a minute or two.”
The researchers pointed out that although time spent doing vigorous activity was the quickest way to improve heart health, small changes could also have an impact if done for longer.
One example they gave was swapping a sitting desk for a standing desk for a few hours a day.
James Leiper, associate medical director at the British Heart Foundation, said: “We already know that exercise can have real benefits for your cardiovascular health and this encouraging research shows that small adjustments to your daily routine could lower your chances of having a heart attack or stroke.
“This study shows that replacing even a few minutes of sitting with a few minutes of moderate activity can improve your BMI, cholesterol, waist size, and have many more physical benefits.
“Getting active isn’t always easy, and it’s important to make changes that you can stick to in the long term and that you enjoy – anything that gets your heart rate up can help.
“Incorporating ‘activity snacks’ such as walking while taking phone calls, or setting an alarm to get up and do some star jumps every hour is a great way to start building activity into your day, to get you in the habit of living a healthy, active lifestyle.”