CHICAGO (CBS) — A Chicago lawyer who coaches runners and runs marathons leaves for Antarctica this week, to attempt a feat few have ever accomplished: completing marathons on all 7 continents, and in all 50 U.S. states.

Brendan Cournane has run 86 marathons. Number 87 in Antarctica would be the historic one for him.

“When you think about all 50 states and all 7 continents; there’s some who have done all 7 continents, there’s some – about 600 – who’ve done all 50 states, but a lot fewer who have done all 7 continents and all 50 states,” he said.

It’s summer in Antarctica, so Cournane said he expects temperatures in the low to mid-30s, with the possibility for snow.

Cournane said the marathon is run on a dirt trail that connects science stations. If it’s snowy, he said he has grippers he can put on the bottoms of his running shoes.

He’s also run a marathon on the Great Wall of China, one at Mt. Kilimanjaro, and one in Australia in which the starting “gun” was actually a total solar eclipse.

When he’s not running marathons, Cournane is a Chicago lawyer who also coaches hundreds of people – virtually and in-person – to run the Chicago marathon.