How can you work out when u just had a leg injury n had a surgery?

You can do upper body workouts with weights. Make sure you are in a sitting position so you don't put pressure on you injured leg. Do sit ups and crunches with your legs propped up on a ball or pillows.

Lie in your back and do leg lifts and circles with the good leg to keep your abdomen and the good leg in shape. Do the same thing on your stomach if your bad leg allows for you to lay on your stomach.
Do plenty of stretching exercises to keep your body flexible and limber.
The main thing is not to stress the injured leg, while keeping the rest of your body flexible and strong.
Good luck, and good for you for not looking at an injury as an excuse to be a total slug!

Ask your doctor if you are allowed to work out.

Sit and do upper-body workouts. Simple as that. And when you regain use of your leg, just start running or whatever you did normally to get back in shape.

start out slow with simple movements such as straighting your leg if you can. If you can walk on it than do so and rely on crutches as little as possible, the simple motion of walking and moving will help to start off with little risk of injury. try to do this as much as possible until you feel safe progressing towards therapy using weights. riding a stationary bike is very good because it has no impact on the knees cushion the medial and lateral meniscus, it can have variable resistance, and it provides a decent range of motion. elliptical machines also provide the same benefits but focus more on the full extension of the leg. As you progress and add weighted work outs as part of your therapy I would stay away from leg presses and squats because the can put a lot of stress on the knee. They are a great exercise for building muscle and I fyou want you can perform them with caution using low weight and high reps until full recovery. when you can implement higher weights into your routine

My son had a broken femur forever. 2 non-unions & 6 surgeries. Over 2 1/2 yrs. He did upper body workout at the gym, and also when the stitches come out..pool excercises.