Hello kid,
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Yoga will improve your body posture relaxes your mind and make u a good, decent and a calm minded person, it releases your stress. Yoga will only concentrate on particular things like mind.
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Workout will help you u to fit, helps you to make a good body posture, will help you to improve immune system and be healthy. Here workout is for all over body including mind.
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Now the point is what is your target? If you just want to be fit then choose workouts and if your target is to spend a easy, peace minded life then go for yoga.  Do let me know your target and if further queries you have