If you are really out of shape, you will need to warm up on a larger scale. Just remember to start off slowly, and work your way up to harder and more intense exercises. If you are an athlete just returning to your sport after the off-season or an injury, you will be more prone to muscle cramps, like those just getting started. By building on the intensity of your workouts, you will build muscle mass more quickly as well, so don’t overdo it from the start, and be sure to take enough time to rest between workouts.
It’s also very important to keep your muscles, and the rest of your body, hydrated. Be sure to drink lots of water before, during, and after your weight training or any other workout. You should supply your body with water before you feel thirsty, so drink at regular intervals.