From the September 2012 issue of Runner’s World

The most unhealthy type of body tissue is also the least visible

By Ian Taylor

THE PROBLEM
Our priorities are all out of shape. When we worry about fat, we focus on the stuff you can pinch between your fingers, the stuff that droops over waistbands and sabotages the silhouette. But something far more sinister is going on beneath the slightly wobbly surface. When it comes to fat, what you see is not necessarily what you've got.

Adipose tissue – plain old fat to you and me – comes in a variety of forms. The stuff just beneath your skin is called subcutaneous fat. It's not particularly pretty but nor is it particularly harmful, so long as you don't carry it in excess. Visceral fat, however, is something else entirely.

“This builds up deep in your abdomen from the top of the liver down. It surrounds your organs, so your liver, pancreas and kidneys are cushioned and floating in a mass of fat,” says Professor Jimmy Bell, a researcher at Imperial College in London who uses MRI technology to map fat in the body.

In recent years, scientists have confirmed that as far as your health is concerned it's what's on the inside that counts. The hidden fat, the tiny globules seeping into your organs and flowing through your bloodstream, is what increases a person's risk of Type 2 diabetes, heart attacks and other chronic health conditions. A recent study published in the journal Hypertension Research is one of many to have established a link between visceral abdominal fat and coronary heart disease.

THE SOLUTION
Although visceral fat clings to your internal organs, its grip is not particularly strong. When you decide to take action – through diet, running or another form of exercise – your body first uses the fat stores that are most harmful to your health. Starting with the lipids in your blood, you then reduce the dangerous fat in your liver, followed by visceral fat in the abdomen, and then finally the subcutaneous stuff you can pinch between your fingers. No matter how far or how fast you can run, so long as you can maintain it, you will keep the hidden hazard at bay. If you move it, you lose it.

WEAPONS OF CHOICE
Running is the enemy of visceral fat. Choose the best kind of training based on your current fitness levels, then strike

Training type: High-intensity intervals
Best for... People with good baseline fitness levels
Why? Research from the University of Virginia found it is the most effective exercise intensity for reducing visceral fat
How? 400m @ 8–10RPE*; Rest for 2 mins; Repeat x 8; 3–5 times a week

Training type: Tempo intervals
Best for... People returning from injury or looking to start a maintainable fitness program
Why? Research from University College London found that exercising for 60 mins three times a week reduces visceral fat by 60 per cent
How?
Run 1600m @ 4/10 *
Run 3200m @ 6-7/10
Run 1600m @ 4/10
Run 3200m @ 6-7/10
Run 1600m @ 4/10

* RPE = rate of perceived exertion. Eight to 10 represents almost maximal effort. Four represents easy running, six to seven ‘comfortably hard’ pace that you feel you could maintain for up to 20 minutes.

Like this article? Subscribe to Runner’s World and save up to A$35 on the retail price (delivered directly to your door) and receive a FREE pair of Brooks socks PLUS if you subscribe for two years you will also receive a FREE Runner’s World watch.

If you missed picking this issue up at newsstands you can purchase your Runner's World back issue here today!