First she needs a warm up, stretch the muscles and prepares the body
Second workout begin exercise
Cool down your heart and body need to relax
Supplements are the most common cause of vitamin A toxicity. Vitamin a toxicity tends to not occur from eating vitamin a rich foods
A consequence you may suffer is an injury. Exercising without stretching can cause injury.
To prevent injuries, because if you are running around and exercising, if you haven't warmed up, you could pull a muscle or injure yourself. Cool downs help calm your body down and lower your heart rate.
All of these are serious health risk from anorexia, however i think the most serious health risk from anorexia nervous is Death.