Take the stairs. The big cruise ships nowadays have elevators, which is a great convenience for some people. But taking the stairs is also an excellent source of exercise, and it requires minimal effort. Avoid the elevators and take the stairs whenever possible to stay in shape while on your cruise vacation.
Swim. Seriously, it's that easy! Take a break from sunbathing to cool off in the pool, and use that opportunity to swim laps or join in on playtime with the kids. You'd be surprised how much exercise you can get in the pool without even realizing you're doing it!
Sign up for an activity or class. The best exercise you'll get on your cruise is the fun kind. If your ship offers fun physical activities, like volleyball, basketball, or tennis, a rock climbing wall, or group exercise classes, take advantage! These classes can fill up early, so make sure to sign up as soon after boarding as possible. You'll be able to stay in good health and still enjoy the best parts about cruising.