Sitting worse than not exercising?

Here's another thing I learned at the Be Active conference, which is admittedly a little hard to wrap my head around, but in many ways makes sense.

First (and the first time I heard about this was 6 years ago): the people who perform the most intense activity tend to have some of the lowest total daily physical activity volumes, in terms of time spent. This makes sense on a couple levels.

• High intensity exercise is more efficient: if you run hard for 20 minutes, you'll burn at least as many calories as if you had jogged for an hour.
• If you play sports, you'll likely try to limit your physical activity throughout the rest of the day so you don't waste your energy before practice or a game, and then afterwards, you'll want to rest and recover

I am a perfect example of this. Back in grad school, every Saturday we'd have a rugby game. Most of our games were in Washington DC, and often we'd drive up, play, and drive back in the same day. For us, it was about a 5 hour drive up--sedentary time. Then I'd play rugby for 2 hours. Then drive back for another 5 hours. And that night what would I do? Get together with the rugby guys to watch a movie or play video games for 3 hours. So for the majority of my waking hours, 2 were spent doing physical activity, and 13 were spent sitting.

Contrast this with my father's typical Saturday. Get up and go walk to dogs for an hour. Come home and do yard work for 4 hours. Maybe go run some errands, where he'd likely spend at least an hour or 2 walking around, interspersed with driving. Etc, etc, etc. To make up some numbers for comparison, we'll say my Dad only spends 5 hours sitting, and 10 hours doing light physical activity throughout a Saturday.

Now, without doing any math at all on these two examples, lets just assume that our caloric expenditure on a given Saturday was equal. Now on the one hand, I'm going to be increasing my fitness level, and my dad's not. Absolute fitness level is currently regarded as the best predictor of health and survival.

What this NEW research is getting at is that sitting time, independent of physical activity, also strongly predicts survival. So that the more time you spend sitting in a day, the worse your survival will be, even if you do hard exercise when you're not sitting. The main presentation had an amazing and very complicated 3D graph to represent the risks of different combinations of physical activity levels and sitting times (low, medium, and high of each). I don't remember the details, so I am just going to make it up to illustrate their point. 

High sitting times, low physical activity times: we'll use this as the benchmark. The risk of getting cardiovascular disease and dying of these people is 100%.

On the opposite side: low sitting times, high physical activity times: 30% risk of CVD and dying

Now what about the inbetweens?

High physical activity and high sitting times: still about 75% risk of CVD and dying.

So the take home message is that, even if you're like me and play sport on the weekend, you can't be a complete bum the rest of the time, no matter how tired you are. Get up and go walk the stiffness out, or go for a recovery swim, or at least just stand and watch your movies.

On a related note, one thing I'm really interested in looking at, which also came up to a small degree at the Be Active conference, is if just standing still is superior to sitting. The main application I see to this is at offices. One of my friends on his own decided to stand at work from now on (he's a computer programmer). He chose to do this because he thought it would help him feel better by forcing him into a better posture, and he says it has significantly helped decrease his neck and back soreness. On top of these benefits, I imagine there would be a slight, but ultimately significant over a whole work week, increase in caloric expenditure.