It is generally recommended to do external rotations before your workout as a warm-up exercise to activate and prepare the muscles around your shoulders. This can help improve stability and reduce the risk of injury during your workout.
Some effective rotator cuff warmup exercises to prevent injury before a workout include arm circles, shoulder external rotations, and shoulder internal rotations. These exercises help to increase blood flow to the muscles, improve flexibility, and reduce the risk of injury during your workout.
You should take 15 minutes to properly stretch before a workout. Failure to stretch properly can result in injury, and can also limit the size and strength benefits of the workout.
You should eat a Meal before you start your workout and after
You should always eating a light and nutritious pre-workout snack before you start your routine. Lance Armstrong has a website that should answer your questions about pre-workout meals: www.livestrong.com/article/58800-preworkout-foods-eat/
It is not mandatory but having a small meal before a workout doesnt hurt. It will give you the energy that you might require for a good workout. Remember not to have a full stomach meal before a workout as it is not recommended.
you should stretch your legs and arms for warming up
That depends entirely on the contents of your pre-workout supplement. You should always check with your doctor or nutritionist before taking, changing, or combining supplements.
You should always stretch before working out. Failing to stretch properly before a workout will result in injuries. Shin splints are a common injury for runners and they are frequently a result of not properly stretching out. "Mountain climber" exercises are a great way to improve agility and speed.
No, you should eat protein before and after, but drink a lot of water during.
You should buy the Firm Workout DVD if you are generally interested in the product. I would recommend reading reviews before purchasing your choice of DVD.
According to the McGill University Department of Physiology stretching before a workout can actually be damaging to a person's body. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071358/
It is generally recommended to do mobility exercises before your workout to help warm up your muscles and joints, improve flexibility, and reduce the risk of injury.