General term for muscle tissue; used in anatomy, fitness, and everyday contexts.
Exercise builds muscle.
I can't lift my arm because of muscle pain.
I do strength training every day to build muscle.
I do sit-ups every night to strengthen my abs.
After exercising, the muscles in my calves feel tight.
This movement really uses the muscles in your back.
After I stopped exercising because of an injury, I lost muscle.
artificial muscle; synthetic muscle