In order to improve your fitness you should focus on some baseline workouts, in generally those workouts are cardio, strength, and combination workouts.

At first there are the cardio exercises which help your heart to pump, without any hard work, the blood through your blood vessels; they also help to burn excessive calories which cause you lose weight. Obviously the easiest cardio exercise is walking; there are many other exercises like running, swimming, and rowing.

Besides those outdoors exercises you can try indoor cardio machine, like treadmills, elliptical trainers and stationary bikes, there are so many workout indoor options available these days, just choose the one that fits well your needs.

The second workout that you should focus on is the strength training which helps to burn more calories; this physical exercise consists in doing some sit-ups, push-ups, leg extensions.
You can combine both cardio and strength training workout, obviously the most popular one is circuit training, and it combines a cardio warm-up and other strength stations, we can also mention two other popular workouts which are yoga and Pilates, both help to improve your strength and flexibility.

Of course constant attention needs to pay toward stretching, regardless of the kind of the workout you are doing, because there is a thick link between stretching and injuries, so in order to avoid any injuries you should stretch the right way and of course this should be done before your workout.

Finally the above workouts can be done at home or by joining a gym, if you feel that you need a professional trainer so joining a gym club would be profitable, there you can get benefit of the latest workout equipment, and enjoy the team work, but if you feel more comfortable by setting up your own space training, you can practice your fitness workouts in your preferred area.