See if there is a fitness center on board, and commit to a daily routine of exercise. Virtually all modern ships have equipment ranging from treadmills to stationary bikes. The fitness center can get crowded, so try to pick less busy times, like early mornings or late evenings, for your workout. If you don't mind missing the on-board entertainment, the fitness center is likely to be sparsely populated during show times.
See if the fitness center offers any formal classes. You may discover offerings ranging from yoga and Pilates to spinning and aerobics. These are usually free; if there is a charge, it will probably be nominal. You may need to sign up ahead of time for the shipboard exercise classes. If so, sign up early, as space may be limited.
Use the jogging deck. Most ships have a specified jogging track, and it can add a pleasant element to your exercise as you power walk or run along an open deck with a beautiful ocean backdrop.
Instead of using the elevator, always take the stairs when going to an upper deck. This will add little bits of exercise throughout your day.
Choose on-shore excursions that include physical activities, like a walking tour of a city or a sightseeing bicycle ride. It might be tempting to take a bus tour, but you'll get a closer, more personal look at the sights and also get in some exercise if you choose an activity that includes a bit of a workout.
Make use of the ship's amenities that promote physical activity. Many newer ships offer on-board ice skating, roller blading and rock-wall climbing. Even ships that don't feature these extras will at least have a swimming pool where you can do laps, or plenty of places to go for a walk.
