Aging Arnold Schwarzenegger, 77, 'Being Slowly Reduced to a Weakling' as Ex-Beefcake's Muscles are 'Wasting Away'

Pumping Iron star Arnold Schwarzenegger is learning bigger isn't always better when you're 77.

The Terminator star, who once mocked "weaklings," has been forced to alternate his he-man gym workouts with gentler physical-therapy exercises to ensure his aging bones don't crumble after years of injuries and abuse, sources told RadarOnline.com.

Said an insider: "He put his body through torture during his bodybuilding days and his Hollywood heyday during which he did many of his own stunts, and he's paid a hefty price.

"He did a lot of damage that resulted in multiple injuries."

In fact, the former Mr. Universe has needed repairs on a shocking number of his body parts, including surgery on his rotator cuff, back, shoulder, leg and both knees.

He's also had three open-heart surgeries, a pacemaker implanted and a hip replacement.

"The aches and pain still linger to this day," the source said. "He's a lot less mobile than he used to be."

But now, the former Twins star is "taking better care of himself and adapted a workout regime that's kinder to his old body, so he doesn't overexert himself."

The Conan the Barbarian strongman "realizes he doesn't have to lift a ton of weights to get results," and now uses resistance bands and body-weight exercises as well as barbells, a source said.

"It's the less-is-more philosophy and he's feeling better because of it."

A rep for the star said: "Arnold has trained with weights for more than six decades and still does at 77. He shares workouts in his free daily newsletter, Arnold’s Pump Club, and shares his current workout in his fitness app, The Pump."

Have a tip? Send it to us! Email RadarOnline.com at tips@radaronline.com.