People who experience flashbacks, nightmares, and impaired functioning following a life-threatening or other horrifying event are .

experiencing posttraumatic stress disorder is the correct answer.

Explanation:

Posttraumatic stress disorder is a severe mental disorder that develops when someone has faced terrifying events such as severe accidents, the sudden death of their family member, war, terrorist event,sexual assault, and natural disaster.

Symptoms of Posttraumatic Stress Disorder are

these are common warning signs of overtraining syndrome:

washed-out feeling, tired, drained, lack of energy

mild leg soreness, general aches, and pains

pain in muscles and joints

sudden drop in performance

insomnia

headaches

decreased immunity (increased number of colds, and sore throats)

decrease in training capacity/intensity

moodiness and irritability

depression

loss of enthusiasm for the sport

decreased appetite

increased incidence of injuries.

a compulsive need to exercise

the maintenance of fluid balance during exercise. author information: fluid supplementation is necessary for exercise in which fluid losses must be offset by intake to avoid the negative effects of hypohydration on health and performance.