Sitting too much: what it does to your body and how to offset it

Why is sitting for long periods a problem?

When you sit for a long time, the big muscles in your legs and back barely work. Your body uses less energy, and glucose and fats in the blood are used more slowly. Over the long term, that's linked with weight gain, type 2 diabetes and heart disease.

The UK's National Health Service (NHS) also lists back and neck pain, especially when you stay in the same position for a long time, and a gradual loss of muscle strength.

Many adults with desk jobs sit for 8 to 10 hours a day, once you add the commute, meals and evenings in front of the TV.

Can movement make up for sitting too much?

In 2016, The Lancet published an analysis of 16 studies with over a million adults followed for years. The researchers compared people by how much they sat and how much they moved.

What they found:

• in very active people, with around 60–75 minutes of moderate activity a day, sitting for more than 8 hours barely raised the risk of death;
• in those who moved very little, the risk was higher even when they sat for short periods;
• the riskiest combination was long hours of sitting and very little movement: 59% higher than in active people;
• watching TV for 3 hours or more a day raised the risk in almost everyone, except the very active.

It's an observational study, so it shows a link and doesn't prove the cause on its own. Its practical message is clear, though: if you sit a lot because of your job, the movement in the rest of your day matters enormously.

How much movement do you need?

The World Health Organization recommends 150 to 300 minutes a week of moderate activity for adults and, where possible, less time spent sitting. For people who sit a great deal, the WHO says it's good to aim for the top end of that range.

60 minutes a day can sound like a lot. It doesn't have to be done in one go. It could be a 20-minute walk in the morning, 15 minutes after lunch, the stairs, walking to the shop and a stroll in the evening.

To see how much you sit and how much you actually move, your free MentorSano account puts small movement steps on your daily to-do list, and the journal shows your steps next to your sleep and energy.

What can you do at your desk?

Habit	How to do it
A break every hour	stand up for 2–3 minutes: a glass of water, a walk to the window, a few stretches
Phone calls on your feet	talk on the phone while walking around the office or down the corridor
Short meetings, standing or walking	a chat between two colleagues can happen on the move
The printer and water further away	every trip adds a few steps
A walk after lunch	10–15 minutes; it also helps blood sugar after a meal
A sit-stand desk	switch between the two; standing for hours on end isn't ideal either

A reminder on your phone or watch every hour helps at first, until the break becomes a habit.

And at home, in the evening?

Evenings tend to add up to many hours in front of screens. A few ideas:

• stand up during every break between episodes;
• do a few simple exercises while you watch: getting up from the sofa, calf raises;
• a short walk after dinner, instead of the first episode;
• housework counts too: cooking, cleaning, gardening.

How can you tell how long you really sit?

Many watches and phones show the hours when you didn't walk at all, or nudge you when you've sat too long. You can also try a simple exercise: on a typical day, note the hours spent sitting at work, in the car, at meals and in the evening. Many people find they go past 10 hours.