A fitness guru to such celebs as Cindy Crawford and Bianca Jagger is holding a $125,000 work of art hostage, court papers charge.

Upper East Side gallery Historical Design says in a Manhattan Supreme Court suit that it lent Radu Teoderescu the two-painting set, called “Gymnasium,” in 2010 for his workout studio. It wants the art or $125,000.

Teoderescu could not be reached for comment.