Ultramarathoner Dean Karnazes holds several records for the longest endurance runs.

In 2005 he ran 350 miles in 80 hours and 44 minutes without sleep. A year later he ran a marathon in each of the 50 states in 50 consecutive days.

Now we don't recommend trying Dean's endurance feats, but we can recommend exercising to the point of seeing what you can endure without injury.

That, in a nutshell, is the definition of endurance training.

Endurance training can be anything that builds strength, whether it's swimming one, then two, then three laps; biking 2, then 4, then 6 miles; or walking 2,000 daily steps on your way to 10,000 or more.

If you are overweight or obese, you can get big benefits very quickly from adhering to this kind of exercise routine.

A recent study from the University of Illinois at Urbana Champaign found that six weeks of this type of endurance exercise training significantly decreases circulating inflammatory progenitor cells in obese adults.

Circulating inflammatory progenitor cells are stem cells found in bone marrow and blood that play a big part in boosting the risk for heart disease, diabetes complications, cancer, joint pain, and dementia. And their numbers are higher in obese and overweight people.

But by pushing yourself just a little harder — a few more steps every day will do it — you can significantly reduce the tissue inflammation they cause.

So set your challenge (whatever helps you expand your physical ability), and be prepared for some ultra rewards.