Mannie was a former walk-on at Akron and eventually became a starting offensive guard for an Akron team that finished 8-2 and ranked eighth in Division II. He previously worked at Ohio State as a graduate assistant and was the strength and conditioning coach for Toledo before joining MSU in December, 1994.

Mannie was elected into the USA Strength/Conditioning Coaches Hall of Fame in 2014, and served on the Collegiate Strength and Conditioning Association Board of Directors. He is currently the longest tenured head football strength and conditioning coach in the Big Ten.

In addition, Mannie has written a monthly column for “Powerline," the nation’s oldest coaching publication, since 2000. He also serves on the advisory boards for organizations such as the National Strength Professionals Association (NSPA), the information-based Athletic Strength and Power (ASAP) website, and the Ultimate Strength and Conditioning website.

Under Mannie’s tutelage, two assistants have gone on to work for NFL teams as strength and conditioning assistants, and numerous others are strength and conditioning head coaches or assistants for universities all across the country.

Two of Mannie’s off-season workout regimens, the “Fourth Quarter” and the “Bottom Line” have helped mold the recruits and athletes that head coach Mark Dantonio has used to contribute to his five 11 win seasons in the past six years and MSU record eight straight bowl appearances, including back to back New Year’s Six bowl victories in the 2014 Rose Bowl and 2015 Cotton Bowl.