Watch on Soap2day. As an avid endurance athlete and someone who is always seeking the next challenge, Justin Kinner was naturally drawn to the Grand Slam of Ultrarunning. The "Slam" is a series of four of the oldest 100-mile foot races in the United States. The Slam starts in Virginia at the Old Dominion 100, followed by the world-renowned Western States 100, just 21 days later in California.