Yungoos evolves into Gumshoos at level 20, during the day. Rockruff will always evolve into Lycanroc, but the form depends on the game you're playing. Midday form appears in Sun, and Midnight form appears in Moon. Type: Null evolves into Silvally with high happiness.
Skeletal muscles are the muscles found in your legs and arms and throughout the body. The skeletal system is different from the smooth muscle system in organs like your liver and the cardiac muscle in your heart because the skeletal muscles contract voluntarily.
Your heart beats faster when you workout because your muscles are working harder, and need more oxygen and nutrients to keep them moving. Since those necessary things are carried to the muscles by your blood, your heart must pump faster to move more blood through your arteries to get to the muscles.