What was Mike Mentzer’s cause of death?

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.

Mentzer's brother, Ray, was the one who found his body. Here's a look at his decline and the circumstances that led to his death.

Mike Mentzer's decline

According to the aforementioned report, Mike Mentzer overused performance-enhancing substances during the 1980's Olympia prep. The 1978 Mr. Universe claimed that he needed to be productive and used amphetamine as a pre-workout, ignoring all the health warnings. The report also claims that Mentzer woke up twice "at death's door" during his prep. He felt so fatigued that he was unable to move a single muscle and stayed in bed until he felt better.

Things went south for Mr. Heavy Duty in the 1980 Mr. Olympia as six-time winner Arnold Schwarzenegger announced his comeback and secured his seventh win, with Mentzer placing fifth.

Mentzer, along with other bodybuilders including three-time Mr. Olympia Frank Zane, boycotted the 1981 Mr. Olympia for an alleged wrongful placement. In 1983, Mr. Heavy Duty became the editor of Workout Magazine. He enjoyed his work but still relied on amphetamines to meet deadlines. This resulted in him staying awake for two to three days at a time.

However, Mike Mentzer lost his job when the magazine shut down. Soon after this, he lost his beloved father, and his 10-year relationship with his fiancee, Cathy Gelfo, also ended. All these events pushed Mentzer closer towards his eventual demise.

Mike Mentzer's competition history

Mr. Lancaster in 1971 - secured first place.
AAU Mr. America in 1971 - secured 10th place.
AAU Teen Mr. America in 1971 - secured second place.
IFBB Mr. America in 1975 - secured third place.
ABBA Mr. USA in 1975 - secured second place.
IFBB Mr. America in 1976 - secured first place.
IFBB Mr. America in 1976 - secured first place.
IFBB Mr. Universe in 1976 - secured second place.
IFBB North American Championships in 1977 - secured first place.
IFBB North American Championships in 1977 - secured first place in the middleweight division.
IFBB Mr. Universe in 1977 - secured second place in the heavyweight division.
IFBB USA vs. the World in 1978 - secured first place in the heavyweight division.
IFBB World Amateur Championships in 1978 - secured first place in the heavyweight division.
IFBB Mr. Universe in 1978 - 1st
IFBB Canada Pro Cup in 1979 - secured second place.
IFBB Florida Pro Invitational in 1979 - secured first place.
IFBB Night of Champions in 1979 - secured third place.
IFBB Mr. Olympia in 1979 - secured first place in the heavyweight division.
IFBB Pittsburgh Pro Invitational in 1979 - secured second place.
IFBB Southern Pro Cup in 1979 - secured first place.
IFBB Mr. Olympia in 1980 - secured fifth place.