What should you choose between yoga and the gym ?

Both have their own advantages and purpose. It's upon you to identify what is your fitness goal and what will be the best to achieve it. And I guess by gym you mean physical exercise, whic can be done anywhere regardless of the location under the guidence of a fitness professional. Ya so it would be much easier to decide what will be best for you after setting a goal.

The yoga is preferable and secondly Gym can also be practiced.The benefit of yoga is physical,mental and spiritual level.Yoga help to relax mind and body and reduce stress level.Yoga increase flexibility,strength and immunity.Yoga keep joints and muscle very free from tense.Yoga prevent against  forthcoming diseases.

The Gym other side keep muscle strong and fitness of body.if Gym practice discontinued, the muscle become again loose.The important thing people use Gym for body building.

Yoga has good effect for longer period though it left.

The practices of Yoga offer flexibility, strengthening, and toning. Yoga is not only about muscles but about raising your consciousness. It takes care of your mind and body together.To practice Yoga, no equipment is required and you can do with a limited space. You do not have to spend long time travelling to the Gym and the best of all you do not have to pay the monthly fees, unless you choose to practice Yoga with a professional.

If you want a body that everyone admires and in a short time, Gym might be the only answer. Gym is great for fast results. 

While a session at the gym can drain you. Yoga does not make you hungrier , instead it regulates the body for optimum intake. Yoga acts on the body, mind, and intellectual well-being.