Mike Mentzer, popularly known as 'Mr. Heavy Duty' for his high-intensity workouts, died on June 10, 2001. Mentzer passed away at the age of 49 due to heart attack, as reported by Generation Iron.

Mike Mentzer is known for his intense training regimen, earning him the nickname 'Mr. Heavy Duty'. His workout included lifting heavy weights until failure. According to Steel Supplements ...

That’s when he told me he was following Mike Mentzer’s ‘Heavy Duty’ training method. For those who don’t know, Mike Mentzer was an American bodybuilder with a very impressive physique ...