Which one of the following measures how well your heart gets oxygen-rich blood to all your muscles while you’re exercising?

a. metabolism

b. muscular endurance

c. endorphins

d. cardiorespiratory endurance

death, cancer and other harmful things to the body

explanation:

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

you may having too much sleep.. a good night sleep consists of about 7 hours. more than that could be the reason you're still tired throughout the day.