I was at the American College of Sports Medicine (ACSM) Annual Conference
in Denver earlier this month, where sports medicine docs, athletic trainers, physical therapists and exercise physiologists from around the world were presenting their most current, cutting edge research1.
Some of the most popular topics for research this year included the damaging effects of sitting.
It may not come as a surprise to you. For the last several years we’ve been hearing bold statements in the media regarding the dangers of sitting. One of the boldest statements I’ve heard to date:
“Sitting is the New Smoking”… But is it really?
I attended a number of research presentations on the dangers of sitting at the conference.
Much of this research went into detail on how sitting for 3, and 6 hours at a time impacts our blood vessels. As it turns out, long-term, uninterrupted sitting can cause endothelial dysfunction, which is the reduced ability of the blood vessels to expand and contract, regulate platelets, antioxidants, and electrolytes. Endothelial dysfunction contributes to hypertension, high cholesterol and diabetes.
But it’s important for you to know that in this research,
Subjects really sat for 3 and 6 hours at a time.
There was no standing up, potty breaks, or water breaks. And most of the time, no leg movement.
Now, that’s something not everyone does on a regular basis, unless you’re in an airplane, driving long distance, in a hospital or physically impaired. If you’re really unlucky, you may have to sit for a 3-hour meeting once in a while. But generally, most of us get up at least once every three hours, and most likely move our legs a couple of times during those hours.
The good news is that these studies showed the dysfunction caused by sitting for 3 and 6 hours can be alleviated
with movement- if it’s done at least once per hour. If you’re not in a place where you can stand up, the dysfunction can also be mediated by heel raising, extending your legs, and other kinds of leg-fidgeting. But the best thing to do would be to get up and walk for 5-10 minutes2,3.
Exercise can make a big difference with this issue.
When subjects from one study exercised before sitting, they were able to keep normal blood vessel function for up to 3 hours of uninterrupted sitting.
So, while sitting does have some very dangerous effects, there are things you can do to reduce your risk.
At the end of one specific symposium presenters stood up and took questions. I asked them point-blank: From your research what conclusion can we take to the public?
The answers were varied to include:
- Any movement is good.
- Fidgeting helps, tapping your heels or moving your legs in some way is good.
- Just stand up regularly.
But, they all agreed that the best way to make sure you’re counteracting the negative effects of sitting for long periods is to get up and walk for 5-10 minutes every hour.
After attending these presentations I’m not sure that I’d say sitting is as bad as smoking. But, long-term sitting combined with other kinds of inactivity probably is.
For example, one study found that when active adults who regularly took 10,000 steps per day reduced their steps to 5,000 per day for 5 days, they significantly reduced their insulin sensitivity and glucose tolerance. And, one day of 10,000 steps was not enough to bring their blood sugar metabolism back to normal4.
So, on top of getting up and moving every hour, you’ll want to continue walking as much as possible.
And, if your daily steps don’t include some heart-rate raising exercise
at least 120 minutes of moderate, or 90 minutes of vigorous exercise every week, you’ll want to add that in to maintain the health and strength of your heart, lungs, and blood vessels. And you’ll want to strength train your total body twice per week to keep muscles and bones strong, and defend against the aging process of sarcopenia.
Fortunately, if you have a desk job, you’re not as bad off as popular news articles may have you think.
For optimal health, move regularly:
- Stand once per hour
- Walk every day
- Get regular exercise
Have a comment or a thought? Share in the comments below.
2. Restaino, Robert M., Lauren K. Walsh, Takuma Morishima, Jennifer R. Vranish, Luis A. Martinez-Lemus, Paul J. Fadel, and Jaume Padilla. “Endothelial dysfunction following prolonged sitting is mediated by a reduction in shear stress.” American Journal of Physiology – Heart and Circulatory Physiology 310.5 (2016): https://www.ncbi.nlm.nih.gov/pubmed/26747508
3. Morishima, Takuma, Robert M. Restaino, Lauren K. Walsh, Jill A. Kanaley, Paul J. Fadel, and Jaume Padilla. “Prolonged sitting-induced leg endothelial dysfunction is prevented by fidgeting.” American Journal of Physiology – Heart and Circulatory Physiology 311.1 (2016): https://www.ncbi.nlm.nih.gov/pubmed/27233765
4. Reynolds, L. J., Credeur, D. P., Holwerda, S. W., Leidy, H. J., Fadel, P. J., & Thyfault, J. P. (2015). Acute Inactivity Impairs Glycemic Control but Not Blood Flow to Glucose Ingestion. Medicine & Science in Sports & Exercise, 47(5), 1087-1094. https://www.ncbi.nlm.nih.gov/pubmed/25207931