Daily short bursts of exercise 'lowers blood pressure'
Adding short bursts of exercise to your daily routine, such as cycling to the shops for 15 minutes or taking the stairs, lowers blood pressure, a study has found.
Increasing exercise habits - in exchange, say, for watching a bit more TV or extending a snooze - is good for the heart, researchers said.
However, they warned that people may need to do more than simple walking to really see changes.
Published in the journal Circulation, the study emphasised that everyday activities which raise the heart rate, such as cycling, climbing stairs or short bursts of running, have the biggest benefits.
Led by University College London (UCL) and the University of Sydney, the research looked at data for 14,761 people who wore activity trackers for 24 hours in a bid to explore the relationship between daily movement and blood pressure.
10 hours of sedentary behaviour
On average over the 24 hours, people spent around seven hours asleep, 10 hours in sedentary behaviour such as sitting, three hours standing, one hour slow walking, one hour fast walking, and 16 minutes taking exercise that increased their heart rate such as running and cycling.
The study found that an extra five minutes of exercise which raises the heart rate, such as stair climbing, running or cycling - in exchange for any of the other behaviours - could lower systolic blood pressure (SBP) by 0.68 millimetres of mercury (mmHg) and diastolic blood pressure (DBP) by 0.54mmHg2.
Systolic is the "top number" in a blood pressure reading and represents pressure when the heart pushes blood out around the body.
Diastolic is the "bottom number" and is the pressure when the heart rests between beats.
At a population level, a 2mmHg reduction in SBP and a 1mmHg reduction in DPB is equivalent to an approximately 10% reduction in the risk of heart disease, the researchers said.
To achieve such clinically meaningful improvements, people would need to reallocate 20-27 minutes from other behaviours to proper exercise for the top number, and 10-15 minutes for the bottom number, the study found.
For example, with systolic blood pressure, swapping 21 minutes of sedentary time, 22 minutes of standing or 26 minutes of slow walking for exercise such as cycling or jogging would have this effect.
For diastolic blood pressure, the benefits would arise from swapping 10 minutes of fast walking, 11 minutes of sedentary time or 13 minutes of sleeping for proper exercise.
Exercise is the key
Dr Jo Blodgett, first author of the study from UCL, said: "Our findings suggest that, for most people, exercise is key to reducing blood pressure, rather than less strenuous forms of movement such as walking.
"The good news is that, whatever your physical ability, it doesn't take long to have a positive effect on blood pressure.
"What's unique about our exercise variable is that it includes all exercise-like activities, from climbing the stairs to a short cycling errand, many of which can be integrated into daily routines.
"For those who don't do a lot of exercise, walking did still have some positive benefits for blood pressure.
"But if you want to change your blood pressure, putting more demand on the cardiovascular system through exercise will have the greatest effect."
Consistently high blood pressure is one of the biggest causes of premature death globally and can lead to stroke, heart attack, heart failure and kidney damage.
The study was funded by the British Heart Foundation.
Its chief scientific officer, Professor Bryan Williams, said: "We know that exercise can have real benefits for your cardiovascular health and also helps to lower blood pressure.
"We recommend doing 150 minutes of physical activity each week, and this interesting study shows that incorporating just a few extra minutes of physical activity each day could help further lower your blood pressure, albeit by a modest amount.
"Anything that gets your heart rate up can help. Incorporating short bursts of activity such as walking while taking phone calls or setting an alarm to get up and move around every hour, are great ways to start building activity into your day.
"These small changes will help get you in the habit of living a healthier, more active lifestyle."