肌肉 (jī ròu): muscle

In order to prepare for next month's marathon, he goes to the gym every day to train his muscles.

After moving house, all my muscles are sore; even lifting my hand feels difficult.

The bodybuilder's muscle definition is very obvious, attracting many spectators' attention.

Sitting for long periods for work easily causes neck muscle stiffness, so the doctor suggested I stand up and move around every hour.

She has been practicing yoga for three years; not only have her muscles become stronger, but her posture has also improved a lot.

With aging, the body's muscle mass gradually decreases, so older adults need to appropriately supplement protein and do some strength training.