Published research on how quickly sitting changes what your body does with a meal · Read this before you buy another class pass
No gym membership. No new programme. A free five minute check that shows which signals in your own answers speak loudest.
"I'm on the go all day, so I'm not sitting still anyway."
But how does this go for most people, in reality? Busy from seven in the morning and spending most of it in a chair. Sleepy after eating, an hour after lunch. A craving for something sweet at four. Getting out of breath on the stairs you used to take two at a time. The walk with the dog that is the main movement of the day. A back that is stiff in the morning when you wake up (and you blame your mattress). Being tired all evening without having done anything physical.
I am Jesse van der Velde. Not a guru and not a doctor. I study and share what published research says about how a body ages. I have been testing that on myself and with the people I guide for more than fourteen years.
The thought I hear many people say is "I move all day”.
But often it turns out to be different in reality from what people think.
And there is published research on what happens when you work sitting down, or study. What happens in your body when you take fewer steps in a day. And that decline goes faster than you think.
VIDEO SLOT · place a video or embed here
Almost everything you hear about moving is about the training or the sport you do.
Three times a week. 30 to 60 minutes. Heart rate up. Excellent, keep it up.
That way of looking at it has one problem.
The rest of the day is about fifteen waking hours, and what happens in them turns out to matter far more.
So when you did those three sessions, but little changed outside them, you wondered why your results were lagging behind.
There is a published study that explains why, and it was built by asking healthy people to move less on purpose.
In 2010 Rikke Krogh-Madsen, John Thyfault and colleagues published a study in the Journal of Applied Physiology.¹
What was studied: whether going from a normal number of daily steps to a low number changes how the body handles glucose, in people who were healthy to begin with.
How: ten healthy young men who did no structured exercise brought their daily activity down from an average of 10,501 ± 808 steps to 1,344 ± 33 steps a day, for two weeks.
At the start and again at the end the researchers did hyperinsulinaemic euglycaemic clamps with stable isotopes, took muscle biopsies, measured maximal oxygen uptake and drew blood. A clamp is the reference method: insulin is brought in at a steady rate and glucose is added at the rate that keeps blood sugar flat, so the amount of glucose needed to do that is the measurement.
The findings: the glucose rate needed fell by 17 per cent. The researchers traced that to a fall in insulin sensitivity in the tissue of the body, and not to anything the liver did, because the liver's own glucose production was unchanged. In the muscle samples the insulin driven ratio of a signalling protein to its total fell, most clearly after four hours of insulin infusion.
Maximal oxygen uptake fell by 7 per cent.
And fat free mass (muscle mass) fell in the legs, while the arms and trunk stayed unchanged.
Oxygen uptake down. Muscle mass down.
Read that again. Two weeks. Healthy young men. Nothing else in their lives was deliberately changed.
What "insulin sensitivity in the tissue" actually refers to.
In 2010 Muhammad Abdul-Ghani and Ralph DeFronzo published a review article in the Journal of Biomedicine and Biotechnology.²
What was studied: what insulin resistance in skeletal muscle is made up of, step by step.
How: a review article that brings the cellular and molecular work together into one story.
The findings: insulin resistance in skeletal muscle shows up as less glucose taken up when insulin is present, and it comes from a disturbed insulin signal plus a number of separate faults further along the chain, among them the transport of glucose into the cell, the phosphorylation that follows, and the burning and storing of glucose after that.
Disruption of fatty acid metabolism plays a central role in that. The authors also report that recent work has found a hitch in the energy production of the mitochondria, across a range of insulin resistant states.
So there is not one single place in the body where things go wrong when you move less.
There is a chain of problems. Insulin resistance, muscle mass, oxygen uptake. All of it gets worse. Already after 2 weeks.
Does this sound familiar? Take the free check now.
Our scientifically validated questionnaire gives you answers
One day. Fourteen people. In 2011 Brooke Stephens, Kirsten Granados, Theodore Zderic, Marc Hamilton and Barry Braun published a study in Metabolism. Fourteen adults, 26 years old on average, lean at 23.7 per cent body fat and well trained with a peak oxygen uptake of 49.1, each did three separate full days. An active day without sitting, on which they used 2,944 kcal and ate the same amount. A sitting day with a use of 2,195 kcal on which the food stayed the same, so there was a surplus. And a sitting day on which the food was brought down to 2,139 kcal to match what they used. The next morning insulin action was measured with an infusion of labelled glucose.³
39 per cent lower after the sitting day. Compared with the active day, insulin action fell by 39 per cent on the sitting day with the surplus (P < 0.001).³
18 per cent lower, even with food brought into line. On the sitting day where food had been reduced the drop was 18 per cent, and that did not reach the significance threshold (P = 0.07). What did reach that threshold was the comparison between the two sitting days: matching food to the lower expenditure kept insulin action higher than not matching it (P = 0.04).³
So a day in a chair does something that a smaller dinner softens and does not undo.
70 adults, and 1 minute 40 seconds every half hour. In 2013 Meredith Peddie and colleagues published a randomised cross-over study in the American Journal of Clinical Nutrition. Every participant did all three conditions: nine hours of sitting; a walk of 30 minutes followed by sitting; and sitting that was broken every half hour by 1 minute 40 seconds of walking. A drink that replaced a meal was given at the same three moments in each condition.⁴
The breaks beat both of the others on the two measures this page is about. Against nine hours of sitting the insulin response across the day fell by 866.7 units (P < 0.001), and against the single walk of 30 minutes by 542.0 units (P = 0.003). The glucose response fell by 18.9 against sitting and by 17.4 against the walk (P < 0.001 for both).⁴
And the result that points the other way, printed at the same size: on triglycerides the single walk beat the breaks, by 6.3 (P = 0.006).⁴ So one approach did not win everything. It won the two things that are measured on the day you eat.
You know how this goes for you. A conversation with a client showed me how this goes for most people.
Seven hours of work a day. Most of it sitting. Sitting on the way to work. Sitting on the way home. Sitting at the table to eat. After eating, sitting on the sofa. Most of our hours, we spend sitting.
For years I read tiredness as proof of effort. I saw it as proof of a long day.
Many people read a tired feeling at the end of the day as “fulfilled”.
While that tiredness actually comes from inactivity.
1. Relying only on the step counter in your phone.
Whether you look at it is of course up to you, and it is better than looking at nothing.
But be clear about what it does and does not do. It counts steps. It says nothing about how those steps are spread out, and in that cross over study the spreading was exactly the variable: the same walking, cut into pieces of 1 minute 40 seconds every half hour, beat one continuous 30 minute walk on both glucose and insulin.⁴
2. One long session at the weekend.
This is the most commonly made plan there is, and the study gives it real credit. In the direct comparison it was the continuous walk that won on triglycerides.⁴
What it does not do is cover the other six days. The two week study took no one's exercise away. It took away their ordinary steps, and insulin sensitivity still fell by 17 per cent.¹
3. Buying a standing desk and then sitting at it.
Owning the desk changes nothing until the pattern of the day changes. The comparison that counted in that study ran between nine hours of sitting and those same nine hours, broken up every half hour.⁴
4. Deciding that you are simply not the sporty type.
This is the one to lay to rest first, because nothing comes after it. The two week study used healthy young men, and the one day study used lean, well trained adults with a peak oxygen uptake of 49.1.¹ ³ Both of those groups moved along with the measurement. Being sporty was not what protected them.
This is the heart of it. If one day in a chair shifts the measurement in trained adults, then "do you do sport" is no longer the useful question.
The question becomes: how do I really do it, on an ordinary day?
Whether you move for half an hour on most days. How often there are vegetables or fruit on your plate. Whether anyone has ever said that a value was too high. What runs in your family. How often the craving for something sweet comes.
And the honest limit, which the scan prints itself: this is a risk picture, not a symptom score, and a blood test confirms it.
That is what the research made available. Krogh-Madsen and colleagues took the steps away for two weeks and measured what followed.¹ Abdul-Ghani and DeFronzo set out the chain that comes under pressure.² Stephens and colleagues brought it down to one day, and separated the sitting from the food.³ Peddie and colleagues showed that how the movement is spread across the day is a variable of its own.⁴
What was missing: a way to lay your own answers beside it.
On one condition. That analysis has to be about you: your movement, your plate, your family, your cravings, question by question alongside what published research describes. A general list of exercise tips does not tell you which signals in your answers are the hard ones.
BioProfile has built that first step. A scientifically validated questionnaire, five minutes, free and with no account.
You answer questions about your movement, your food, your history and your cravings. After that you see which signals in your profile speak loudest, and what the research says about them. Not a medical examination. An analysis of your own answers. You use the outcome yourself, or you put it on the table with your doctor.
You do the free check. Five minutes, no account, and there is nothing to buy.
Even if you do nothing with it, you have traded "I am too busy to sit still" for an analysis of your own answers. That trade is worth five minutes.
And the next time an hour goes by in the same chair, you know what that hour is doing while you work.
Do it while this page is still open. Tomorrow has fifteen waking hours either way.
Our scientifically validated questionnaire gives you answers
The scan is not a medical examination. It is an analysis of your own answers. If complaints persist, consult your doctor.
