The star, who also fronts Britain's Got Talent and The X Factor in his native U.K., tells British tabloid the Daily Mirror that he makes up to four transatlantic flights a week just to keep up with his hectic filming.
He also heads a record label and a television production company.
And despite insisting he feels fit and healthy, Cowell admits his American commitments may face the axe once his contract is up next year.
He says, "I don't want to come over as whiney because I am very grateful that I have got these jobs. But there is a point where I am not sure we can keep this schedule up.
"It takes longer and longer to make these shows because you have to put more into them, and I am not sure we can sustain me doing three shows a year, with the record label and the TV production company.
"Most people do one show a year and I do three and they involve a lot of travelling. One may have to go. I don't know which one. That is the problem, I like all of them. I can't imagine not doing Britain's Got Talent and I can't imagine not doing X Factor.
"But I guess America is more likely to go because I have got one year under contract. Maybe that will be the end."
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