Experts say too much caffeine alone can cause caffeine intoxication, leading to insomnia, anxiety, restlessness, muscle twitching.

专家表示， 单独摄入太多咖啡因会导致咖啡因中毒，导致失眠、焦虑、烦躁、肌肉抽搐。

She straightened up suddenly, though it was clear she was pressing her feet down hard on the floor; from behind, I could see her leg muscles twitching.

她突然直起身来， 尽管很明显她的脚正用力地踩在地板上。从后面，我可以看到她的腿部肌肉在抽搐。