Mike started running to stay in shape for his first passion in athletics—wrestling. He left high school with the most wins in Hudson High School history, and a 119-24 career record, which included a Wisconsin state best 41 wins in his senior campaign. After spending two years on the University of Wyoming Cowboy wrestling team, he transferred to the University of Wisconsin-Madison to finish up his undergraduate studies.

At the U of Wisconsin, Mike enrolled in a marathon training class in his last semester, and ran the 2004 Mad City Marathon as the final exam for the PE elective. He ran a 2:36—good enough for third place overall—and he was hooked. Two years later, he earned his first bid to the Olympic trials at the Grandmas Marathon, running a 2:20:28.

Before joining Team Strands, he spent the two years training in Rocehster Hills, Michigan with the Hansons-Brooks Distance Project, where he improved his marathon best to 2:16:20 at the 2008 Bank of America Chicago Marathon.

His father, Jeff Reneau, was 10th in the 1968 Olympic Marathon Trials and 11th at the 1969 BAA Boston Marathon. In 2007, when Mike placed 32nd in the U.S. Olympic Marathon trials, they became the first father/son duo to compete in the Olympic Marathon trials.