Some nights chang has problems falling asleep. other nights, he wakes up several times during the night and has difficulty returning to sleep. chang likely suffers from which sleep disorder? â

Insomnia would be your answer. Insomnia means, persistent problems falling and staying asleep.

Awoodchuck could chuck around 700 pounds worth of wood

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.