A book that suggests that corporate executives need to be fit as well as success-oriented has just made a strong six-figure sale to the Free Press at Simon & Schuster via senior editor Fred Hills, who won the tentatively titled Becoming a Corporate Athlete by Dr. Jim Loehr, writing with Tony Schwartz, at auction. Loehr runs a Florida-based workshop operation called LGE (in which Schwartz is a partner) which treats athletes as well as business types, and has found they have many needs in common, including the need for periodic recovery and renewal of physical and spiritual energy. Hills beat out two other leading contenders, Viking and HarperCollins, in the stretch to win North American, first serial and audio (paperback to Fireside) rights in a sale negotiated by agent Alice Martell. She has already, she said, received preemptive offers from Germany and Israel.