Monday, January 12, 2009

Fat people don't cope well with stress and it makes them stupid

Now this is what I call an experiment!



Sorry for the harsh headline, but that is me dumbing down the study below.

I've written about stress before and Dr Dan had a good post on the subject today too. Stress via increased cortisol can make you fat, but now this indicates that when you are fat you cope less well with stress. A nasty vicious circle.

Higher body fat percentage is associated with increased cortisol reactivity and impaired cognitive resilience in response to acute emotional stress


Objective:

Cortisol is elevated in individuals with both increased emotional stress and higher percentages of body fat. Cortisol is also known to affect cognitive performance, particularly spatial processing and working memory. We hypothesized that increased body fat might therefore be associated with decreased performance on a spatial processing task, in response to an acute real-world stressor.

Design:

We tested two separate samples of participants undergoing their first (tandem) skydive. In the first sample (N=78), participants were tested for salivary cortisol and state anxiety (Spielberger State Anxiety Scale) during the plane's 15-min ascent to altitude in immediate anticipation of the jump. In a second sample (N=20), participants were tested for salivary cortisol, as well as cardiac variables (heart rate, autonomic regulation through heart rate variability) and performance on a cognitive task of spatial processing, selective attention and working memory.

Results:

In response to the skydive, individuals with greater body fat percentages showed significantly increased reactivity for both cortisol (on both samples) and cognition, including decreased accuracy of our task of spatial processing, selective attention and working memory. These cognitive effects were restricted to the stress response and were not found under baseline conditions. There were no body fat interactions with cardiac changes in response to the stressor, suggesting that the cognitive effects were specifically hormone mediated rather than secondary to general activation of the autonomic nervous system.

Conclusions:

Our results indicate that, under real-world stress, increased body fat may be associated with endocrine stress vulnerability, with consequences for deleterious cognitive performance.

3 comments:

Marc said...

Chris,
A little off topic here.
I clicked on what you are reading.
The Greatest exercise machine of all.
What do you think about the exercises and the article? I liked it. I do not have the mobility/felxibility to pull of a quality one legged pistol. But the others I did ok in. (no, I did not crank out 10 one armed pushups ;-))

Chris said...

For other readers - when it pops off the list - the article is here

Marc:

Hi there. I think that is a great article and agree with the points that Maxwell makes. He - as I've posted before - is an amazing and inspirational athlete.

One thing that can concern me about bodyweight exercises is the boredom of high reps and the wear and tear on the joints. However he chooses tough moves where you simply can't do that many reps.

I am no great athlete at these by the way - I can do a single pistol - there is a balance thing to them- a few one arm pushups and a maximum of about 6 chins. There is a good pistol tutorial here.

As ever, thanks for the comment

Marc said...

Thank you Chris.
That was a great link!!
From tennis and soccer my ankles and hamstrings are tight.

Marc