Vince McMahon may be a septuagenarian, but don't try telling that to the WWE chairman.

It has been well documented over the years that McMahon, whose passion for wrestling extends to bodybuilding and fitness, is a full-blown workaholic who pushes himself to the limit.

“I don't like to sleep. I'm missing something when I'm sleeping,” the 71-year-old leader of the world's biggest wrestling company likes to say.

And he's not just exaggerating. His voracious work ethic includes a brutal training regimen that would put many of the performers on his WWE roster to shame.

McMahon, however, recently suffered a major setback that threatens to slow down his breakneck work schedule. During a rigorous training session, he severed his quadriceps while doing squats with heavy weights.

In typical McMahon fashion, the injury wasn't enough to keep him out of the office, as he reportedly was back at work a day after undergoing surgery.

McMahon, who reportedly wanted to keep the injury secret, missed the Backlash pay-per-view and a series of TV tapings, but is said to be recovering nicely.

The injury wasn't the first time that McMahon suffered a major injury to his quads. At the age of 59, he severed both quadriceps tendons as a result of a blown finish at the 2005 Royal Rumble. A controversial ending to a match between John Cena and Batista forced the WWE owner to make an unplanned appearance, and in doing so tore one of his quads while hurriedly sliding into the ring

“I was sprinting as fast as I could and I dove into the ring ... I wasn't warmed up, I didn't stretch and that unfortunately is major surgery,” he later admitted to the Wall Street Journal.

McMahon, of course, played off the incident like a pro after being helped from the ring. He refused help from son Shane and attempted to walk from the building unassisted, but when putting all of his weight on his left leg to compensate for the injury to his right leg, that leg buckled and he suffered the tear to the left quad as well.

Doctors sewed his quadriceps tendons back through his kneecaps, and in the process cleaned out his knees. “They're stronger now than even Mother Nature had intended,” McMahon would boast. “You always have to turn negatives into positives.”

McMahon was out of action for months following that injury, but worked his legs back into lifting gradually, eventually returning to leg-pressing 800 pounds for reps and doing free weight squats with a safety squat bar.

While the latest incident only involved one quad tear, McMahon is 11 years older and, at age 71, the recovery process looks to be an arduous one. But like anything else he takes on, McMahon doesn't take no for an answer.

McMahon, who became the front cover of Muscle & Fitness magazine in 2006 when he was 60 years old, graced the cover a second time last year. He told the magazine that age has nothing to do with his outlook.

“Age really doesn't have anything to do with it,” said McMahon, who had done 700-pound squats before his double quad tear. “I had a personal best a few weeks ago on the incline Hammer Strength machine. I did five reps with 450. It's important to make gains, but it's important to be safe. If you have an injury in the gym, it sets you back so much it's not worth whatever gain you were going to make. That's why strict form is so important. It's about form, not the weight.”

McMahon, who admitted to taking steroids years ago, says his muscles these days are due to his workout plan. His feats are even more impressive considering the fact that he doesn't have the luxury of time.

The third-generation promoter considers the gym sacred ground and trains in his corporate WWE facility where neither growling muscleheads nor cell phones are allowed. It's a place where “Go hard or go home!” is the motto.

And no one goes harder than Vince McMahon.

“I'm still making gains,” McMahon told Muscle & Fitness last year, revealing at the time that he was 240 pounds with five percent body fat.

His tenacious work ethic is legendary among those who have worked in WWE. Company executive Paul “Triple H” Levesque called his father-in-law “a machine.” Wife Stephanie McMahon agrees. “He leaves the office at 11 at night and then goes to the gym,” she told TMZ earlier this year.

Pat Patterson, McMahon's right-hand man for many years, laughed when Newsweek asked him about the possibility of his longtime friend retiring.

“Never. There was a convention for workaholics in Chicago once and I said to Vince: 'You should go there.' You know what happened? No one showed up ... they were all too busy working.”

Reach Mike Mooneyham at bymikemooneyham@gmail.com, or follow him on Twitter at @ByMike Mooneyham and on Facebook at Facebook.com/MikeMooneyham.