Which benefit of stretching can make your mood better after exercise ?

One possible explanation could be that aerobic exercise produces endorphins, or “feel good” chemicals. It also increases your heart rate, which triggers norepinephrine, a chemical that may help the brain deal with stress more effectively. Plus, exercise helps to increase blood flow to the brain.

you spelled it wrong - it's obesity.   there is a lot of info on this topic on line.   just google some health articles.  

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