Most of us have heard how sitting in our chairs all day long is bad for our health. Not only does it pack on pounds, but it also bumps up blood pressure, blood sugar, unhealthy cholesterol levels and excess body fat around the waist. It also weakens our musculoskeletal system and can cause vascular problems such as deep vein thrombosis, a condition in which a blood clot forms in a deep vein in our body, most often in the legs.

Although the medical community consistently advises us to get up and get moving, they haven’t answered these two practical questions: How often do we need to get up? And for how long?

A recent study led by Keith Diaz, an associate professor of behavioral medicine at Columbia University Vagelos College of Physicians and Surgeons, has those answers. The key finding -- just five minutes of walking every half hour during long periods of being seated can offset sitting’s most dangerous effects.

The only amount of walking-to-sitting ratio that significantly lowered both blood pressure and blood sugar was 5 minutes of walking every 30 minutes.

Unlike past studies that only looked at one or two exercise options, this study explored five different exercise breaks:

  • One minute walking every thirty minutes of sitting
  • One minute walking after 60 minutes of sitting
  • Five minutes walking every 30 minutes sitting
  • Five minutes walking after 60 minutes sitting
  • No walking at all.

The only amount of walking-to sitting ratio that significantly lowered both blood pressure and blood sugar was 5 minutes of walking every 30 minutes. This walking/sitting routine also had a notable effect on how participants responded to large meals by reducing blood sugar spikes 58 percent compared to just sitting all day.

“If we hadn’t compared multiple options and varied the frequency and duration of the exercises, we would have only been able to provide people with our best guesses of the optimal routine,” Diaz said in a press release.

The study was a small one with only 11 adult participants who came to Diaz’s laboratory, sat in an ergonomic chair for 8 hours and only stood up for their prescribed amount of walking on a treadmill or for a bathroom break. Researchers observed the participants during this period and checked their blood pressure and blood sugar. Both measurements are indications of cardiovascular health.

All walking regimens, except walking for one minute every hour, offered significant decreases in fatigue, as well as significantly boosting mood.

During the 8 hours, participants were permitted to use their laptops, phones and read. They were also given standardized meals. The researchers also regularly checked the participants’ moods, fatigue and cognitive performance. All walking regimens (except walking for one minute every hour) offered significant decreases in fatigue, as well as significantly boosting mood. None of the walking periods had any effect on cognition.

“The effects on mood and fatigue are important,” Diaz points out. “People tend to repeat behaviors that make them feel good and that are enjoyable.”

Diaz isn’t done exploring the relationship of walking breaks on our health and is currently testing 25 different routines.

“What we know now is that for optimal health, you need to move regularly at work, in addition to a daily exercise routine,” Diaz says. “While that may sound impractical, our findings show that even small amounts of walking spread through the work day can significantly lower your risk of heart disease and chronic illness.”

The take-away is simple. If you want to stay healthy, even if you’re deeply engrossed in your work, don’t just sit there. Take a five-minute walking break at least every half hour.

The study is published in Medicine & Science in Sports & Exercise.