Even very small changes in muscle size can make a big difference in strength. This is especially true in people who already have lost a lot of muscle. Increased strength improves your ability to do things such as getting up from a chair or climbing stairs.
Your muscles are active even when you are sleeping. Their cells are still doing routine activities they need to do to stay alive. This work is called metabolism, and it uses up calories. That can help keep your weight in check, even when you are asleep!
To do most strength exercises, you need to lift or push weights. You will need to keep gradually increasing the amount of weight you use. You can use hand/ankle weights sold in sporting goods stores. You can also use things such as empty milk jugs filled with sand or water, or socks filled with beans and tied shut at the ends.