五、Preparation for an Activity准备活动

For a footballer to work at optimal level his muscles have to be prepared with warming up and stretching is vital before any strenuous activity． Warming up and stretching not only gives a good magnitude for gestural ease and less muscle tension but also prevents injury． For instance，if warming up and stretching has not been enough the force executed by quadriceps could give rise to injury to the hamstring，reason being the quads are very strong and exert tremendous force． ^［5］ The hamstring has to be strengthened as well but many neglect this muscle．

为使足球运动员在最佳状态下运动，肌肉系统在任何剧烈运动前的准备活动中预热和伸展非常重要，热身和伸展活动，不仅使机体灵活柔软，肌肉紧张感减轻还可预防伤病。比如：若热身和伸展活动不充分，股四头肌用力可能导致肌腱受伤。因为股四头肌太强壮了，可产生巨大的力。所以必须加强肌腱的力量训练，但很多教练员忽视了这块肌肉的训练。 wHSq8DsWSqfNllxcVf9ipwa3fOPWmBD2DG1AxIfc3Hds96miJp1N7Pr1pbGJRXs8