ROBERT IRWIN HANGING BY A THREAD

The in-demand star is putting his health at risk with his exhaustive schedule

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He's one of the most popular stars in the world right now, with his run on Dancing With The Stars catapulting him to stratospheric new levels in the US.

But is Robert Irwin's rapidly ascending star doing his health more harm than good?

"Robert doesn't know how much more he can take," a source close to the Irwins spills to Woman's Day. "The stress is getting to him. He's put so much pressure on himself, both Bindi and Terri are worried.

He's wound up so tight, they're terrified he's heading for a mini breakdown.

"But he's only making it worse by not being able to sleep. His body aches and as much as he loves the dancing and the performing, he's running out of steam fast."