The Fitness Guide: Where to Work Out When You're on the Road.

You've finally gotten into shape but constant business travel threatens to thwart your exercise regime. Although most hotels have gyms, many are poorly equipped. Others have begun offering "exercise rooms" or in-room equipment rentals, but fees can be as much as $50 a day. Some hotels have even stopped issuing local jogging trails because of safety concerns.

These are a few of the things that frustrated business traveler and fitness buff Kyle Merker, a former accountant with Arthur Andersen, when he traveled. "It was difficult to maintain my exercise routine. You'd get to the hotel gym and find a broom closet with a bike in it," says Merker. That experience inspired him to write, The Fitness Guide: Where to Work Out When You're on the Road (Incline Press; $14.95) for other hindered exercisers. The pocket-size book lists impressive hotel gyms and local fitness centers in major business cities around the country that allow day guests. Merker has worked out in all 400-plus entries, rating each on equipment, amenities, atmosphere, locker room facilities and costs, which can range from $5-$25 daily.

Among the hotels with excellent facilities is the Four Seasons Resort and Club (800-3323442) in Irving, Texas. Free and open to guests only (some hotels charge guests), its 176,000sq.-ft. Sports Club is full-service and housed in a separate budding. It features strength and cardiovascular equipment, tennis classes, indoor and outdoor pools, a spa, golf course and basketball court.

Merker ranked Chicago's six-level Athletic Club at the Illinois Center (312-619-9000) one of the best equipped clubs. A day pass, available only to guests at select hotels, costs $ 18.