One form of exercise that is extremely fun and easy to exercise with is sleds. It is entirely concentric and is pushing against friction instead of gravity, which created the eccentric movement that can damage muscles. If you can use the sled, doing this before reaching a level of exhaustion is a perfect way to trigger the usage of your muscles. Since activities are required to maintain the strength that your muscles do have with muscular dystrophy, this is a safe exercise to achieve this goal.
My physical therapist introduced this form of exercise to me. It is a perfect way to improve strength, improve the cardiovascular system that can prevent you from getting colds, enhance fat loss that may come from medicine usage, and will condition your entire body. While people typically push a sled running, I walk as fast as I can with the sled because it takes the pressure away from my lower body. It can function as a push, pull, or drag exercise instead of requiring weighted instruments to do so.
It is one of my favorite types of exercise because I challenge myself to push it as fast as I can, and occasionally have someone hold a rubber band around my waist to make it more challenging. I found it is a perfect way to improve my endurance, which allows me to bike, swim, row, and walk on the treadmill. Cardio is not as damaging as weight-lifting (if performed correctly) and can serve as a safer way to introduce exercises into your lifestyle.
The exercise is a perfect start to the morning since there is a reduced recovery time between exercise and can start your blood pumping early in the morning. Along with physical benefits, it reduces stress in the body allowing your brain to perform a task or learn things from college or school in general.
I would recommend understanding how to correctly perform this exercise by watching a video, asking a personal trainer, or a physical therapist who can ensure it has a substantial benefit. I enjoy this exercise because it is low impact and does not seem to stress my muscles in any way. I use it as a warm-up before doing a workout as it gets my mindset on the next few exercises to come. It is an incredibly safe exercise tool and can have profound effects if used correctly and at a frequent rate.