Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

运动前的热身非常重要！尤其是冬天，由于气温较低，血管更容易处于应激状态，肌肉和关节更容易僵硬。所以建议大家做一些简单的拉伸运动，比如腿部、背部和手臂的拉伸，或者一些低强度的有氧运动，如快走或慢跑。