Questions about Michael Jackson's health have dominated conversations about the pop icon since his unexpected death last week from cardiac arrest.
But the singer's trainer, actor and bodybuilder Lou Ferrigno, said Jackson was "in fantastic shape."
"He might have been a little thin because he was under a lot of stress training for the tour," Ferrigno, who played the Hulk in "The Incredible Hulk" TV series, said in an interview that aired on "Good Morning America" today. "But when I put him through the routine and everything, I mean, it was just fine. I mean, very energetic."
He said Jackson could have handled his tour, which was scheduled to begin next month.
"He was dancing as good as anyone. And, you know, I'm an expert. And I was with Michael. If I didn't feel Michael could've pulled this off, I would've told him," Ferrigno said. "I think he was going to give the greatest tour in his entire life."
Ferrigno's assessment of Jackson's physical condition stands in stark contrast to one writer's description of the Gary, Ind., native.
Ian Halperin, who is publishing a new biography on the "Thriller" singer, wrote in December that Jackson had only six months to live. He said Jackson suffered from a rare form of lung disorder.
"On some days, he could barely talk," Halperin wrote recently in a British publication. "He could no longer dance."
Halperin said it would have been impossible for the father of three to complete one concert, much less the 50 he had planned.
Halperin, whose book, "Unmasked: The Final Years of Michael Jackson," is due for release in late July, said the former Jackson 5 lead singer was suicidal on some days.
The singer's representatives have denied claims that Jackson's health was on the decline, saying the "moon-walker" passed a four-hour physical in preparation for his London concerts.
Ferrigno, who has known Jackson for 15 years, said the pop icon was "very energetic" during workouts and "was in fantastic shape," although "he might have been a little thin because he was under a lot of stress training for the tour."
Ferrigno, 57, said he last trained with Jackson, 50, about three weeks and would go to the singer's home three or four times a week.
The two used tools like exercise balls and did a lot of core training to get Jackson in shape.
"He didn't want to weight train. So he mostly wanted to deal with flexibility and conditioning," Ferrigno said. "He didn't look like he was in pain because he was on the treadmill. He did the stretching exercises."
In addition to training, it seems that Jackson kept a strict diet.
"I think he was a vegetarian. And he only ate once a day. But I just told him the proper supplements to take," Ferrigno said. "The most important thing was the attitude, the mind because he really wanted to be in his best shape."
According to lighting designer Patrick Woodroffe, Jackson didn't always appear in peak condition during rehearsals for his upcoming tour.
"The sense in the camp was that we were nervous. We were nervous about whether we would be able to pull off the show," he said in a BBC radio interview.
The singer would often miss rehearsals, said Woodroffe, who watched Jackson rehearse two days before he died.
But his final rehearsal began to change the view of the crew.