When the muscles start to tense, the stretch is beginning.

A muscle in his face started to twitch as he quickly turned and walked back to the steps.

Her muscles had started screaming hours ago, but she wasn't about to complain.

The man was large, but his muscle had long since started to turn to fat.

The good news is that when you do the same activity again, your muscles will start to get used to it.

The muscles in his legs started to push him forward.

I felt like all my muscles were starting to atrophy.

Those muscles then start to weaken and eventually get smaller.

But you also have to change speeds, and that's very hard to do when your muscles start complaining.

"The muscles in my right leg started to wear out," he said.