Is it possible to stay in shape abroad? Do students join gyms?

While I'm not much of a gym person, I know several people on my program who were and none of them had a problem. Most of them used the university gym, as we were direct enrollment students. One joined the swim team and another the track team. Several joined the climbing club. One went for a lot of runs.
For students who are not direct enrolled in a university, it may take more effort, but there were plenty of gyms around if you wanted to join them.

You do A LOT of walking and traveling while you're abroad so if you're not a gym person that alone will keep you fit. there are gyms everywhere, you just have to find them! And yoga classes as well.

Hi Kaitlin,
To answer your first question: yes, it is absolutely possible to stay in shape while studying abroad! Chances are you'll be in a fairly big city, so you'll have access to gyms, fitness classes, yoga studios and most of the same kinds of services you'd have at home. As one of the other commenters suggested, you might be able to use the gym at your university, which should have almost everything you need. If that's not an option for you, there will likely be a gym pretty close to where you live -- keep in mind that it may be smaller than what you're used to, but that doesn't mean it won't do the job! Many gyms and facilities offer promotional pricing for new students, so be sure to ask about prices or even try shopping around to see where you can get the best value.

Running or biking trails are a bit trickier, depending on where you're studying. If you're in a very bike-friendly city like Amsterdam or a fitness-loving place like Rio de Janeiro, you should have no problem finding outdoor exercise spaces. Other cities, especially if they have lots of hills, major air pollution or just a lack of parks and green spaces, may not have the same kinds of outdoor amenities, so you'd be better off sticking to the gyms.