How does sitting affect health and how much exercise do we need to counteract the effects of inactivity? Are 10,000 steps a day really enough to preserve health and beat back the crawling death of prolonged sitting? Is there a distinction between too little exercise and too much sitting?
In a new study, researchers went combing for answers, studying the effects of acute exercise on metabolic health markers.
Before we take a look, let’s be clear that this article won’t be focusing on biomechanical implications of inactivity. Research connecting sitting with poor posture and pain has failed to live up to the outrage. Links between inactivity and metabolic decline, however, are gathering steam.
We know that exercise can immediately drive a bunch of metabolic benefits that can last for at least a day after. Insulin sensitivity, glucose tolerance, postprandial lipemia and a myriad of other cardiovascular disease risk factors have all improved after acute exercise.
But, new research has found that after a dose of prolonged sitting, these exercise benefits may not be as powerful.
Scientists from the University of Texas have discovered that a period of sedentary behaviour triggers what they’ve called ‘exercise resistance.’
This is where after a period of inactivity, you can become immune to the benefits derived from an exercise bout.
Ten untrained and recreationally active volunteers completed two four-day periods, consisting of:
- Sitting for 13.5 hours per day, taking less than 4,000 steps.
- Sitting for 13.5 hours per day, taking less than 4,000 steps, with a 1-hour treadmill workout on the evening of the fourth day.
The morning after, participants completed a high-fat/glucose tolerance test, analysing plasma triglycerides, glucose, and insulin response. The aim was to compare findings and unfold the impact of a single exercise bout on metabolic health markers.
So, how does sitting affect health?
Interestingly, they found no differences in lipid, glucose and insulin metabolism between trials.
These results suggest that prolonged inactivity before exercise induces a kind of ‘exercise resistance.’ Where the body fails to respond with the usual cascade of metabolic improvements following exercise.
It remains to be explored whether the same exercise resistance might occur after a single day of sitting. Another avenue would be to look at how much activity it would take to mitigate this metabolic stagnation if your job requires you to sit all day long.
Plenty of things left to dive into here, but two things that emerge out of the clutter, clear as crystal:
1. The more you sit, the less you’ll gain from a given amount of exercise, thanks to exercise resistance.
2. Consistency beats intensity, every time.
Keep it moving.
- Inactivity induces resistance to the metabolic benefits following acute exercise. Atkins, et al. 2019