Stop sitting for hours: two minutes of walking every 20 minutes

Key points

A seated day is not a verdict. In an experiment in adults with overweight, two minutes of easy walking every 20 minutes made sugar and insulin after a meal about a quarter lower and blood pressure three points lower over the day. The benefit came from walking; in a different experiment (10 adults without obesity) no reduction from standing was shown.

Who was tested and how

In an Australian experiment, 19 adults aged 45-65 with overweight (average body mass index 31.2 kg/m²) spent three days in the laboratory in random order: sitting without a break, or walking for 2 minutes every 20 minutes at an easy 3.2 km/h, or at a moderate speed. After 2 hours of sitting they drank a test drink (75 g glucose and 50 g fat), and sugar and insulin were measured for five hours (Dunstan D W Diabetes Care 2012. PMID 22374636^[1]).

Sugar and insulin

The total sugar rise over 5 hours was 6.9 mmol/L·h (124 mg/dL·h) with uninterrupted sitting, 5.2 (94 mg/dL·h) with easy walking and 4.9 (88 mg/dL·h) with moderate walking. That is about a quarter lower with easy walking and slightly lower again with moderate walking. Total insulin rise: 829 pmol/L·h (119 µIU/mL·h) versus 634 (91 µIU/mL·h) with easy walking (Dunstan D W Diabetes Care 2012. PMID 22374636^[1]). The pancreas needs less insulin to cope with the same load.

Blood pressure

In the same 19 people on the same day, systolic pressure with sitting broken up by easy walking was 120 mm Hg versus 123 with uninterrupted sitting, diastolic 76 versus 79. With moderate walking it was 121 and 77 (Larsen R N Nutr Metab Cardiovasc Dis 2014. PMID 24875670^[2]). Three points is modest, but easy: nothing to buy. Measurements were single readings once an hour, and the experiment lasted one day.

Standing is not enough: you need to walk

In another experiment, 10 adults without obesity completed three sessions: sitting, sitting with 2 minutes of standing every 20 minutes, and sitting with 2 minutes of easy walking. The total area under the sugar curve over 5 hours (not the rise, but the whole level) after two test drinks was 18.5 mmol/L·h (333 mg/dL·h) after walking versus 22.0 (396 mg/dL·h) with sitting and 22.2 (400 mg/dL·h) with standing. Blood pressure and cholesterol over the 5 hours did not differ (Bailey D P J Sci Med Sport 2015. PMID 24704421^[3]). The conclusion: if you want to help your sugar, the break must include steps.

How to apply this

• Set a timer for 20-30 minutes. Stand up, walk for two minutes, come back.
• Walk during calls, to get water, to the printer, on the stairs.
• After a meal, go for a walk rather than sitting down at once.
• Tie the break to a task: finished an email, take a walk.
• No need to rush: in the experiment the speed was easy, 3.2 km/h.

Who should see a doctor first

If you have chest pain or breathlessness on walking, dizziness, severe joint disease or recent surgery, discuss activity with a doctor. In diabetes with medicines that can lower sugar, measure glucose and record the results.

A repeat glucose result below 3.0 mmol/L (54 mg/dL) or above 8.9 mmol/L (160 mg/dL) is a reason to see a doctor. In diabetes targets are individual, and below 3.0 mmol/L (54 mg/dL) always means a doctor. Do not change prescribed treatment on your own.

Bottom line

If your work is seated, do not wait for an evening workout: interrupt sitting with two minutes of walking about every 20 minutes. For sugar, insulin and blood pressure it is an inexpensive way to help yourself today.

A real-life example: you are writing a document. Every 20 minutes a timer reminds you: get up, walk through the flat or corridor, pour water, come back. A working day gains a couple of dozen breaks and costs less than an hour.