A Des Moines man who’s considered an “extreme runner” is giving a pep talk tonight for other runners who aspire to tackle the challenge of ultra-marathons. Rusty Bishop has completed four major endurance events in the past four years and says it’s a matter of training — your mind and body. He says the biggest part of the run is mental, not physical, though he says “There is pain that’s involved in many these runs; it’s how your body tolerates that pain, mentally and physically.” Two of the ultra-marathons Bishop has run were 150-mile seven-day tests through the Sahara and Gobi deserts. All runners had to carry a week’s worth of food, clothes and supplies in their backpacks. He’s also run the RAGBRAI course of 374-miles across Iowa in nine-and-a-half days. Bishop’s first marathon was a fundraiser in 1996. He runs to raise money for medical research into blood-related diseases and cancers, primarily through the Leukemia Society. Bishop is 35 and says at many ultra-marathons, he’s among the -younger- participants. Most extreme runners, he says, are closer to 50. He says “You have to want to do this. You have to have that desire and I think a lot of younger individuals don’t have that desire to put their bodies through that type of pain and go those distances.” Bishop, who runs the Gong Fu Tea House in Des Moines, has degrees from Iowa State and Drake and is a Des Moines native. His free seven p.m. talk tonight is at the Jester Park Lodge in Granger.