求翻译：研究发现，在培养过程的各种因素中，应力刺激具有非常重要的作用[17]，尤其是对于运动系统的组织是必不可少的[ ]是什么意思？

Study found that in the process of training in a variety of factors, stress stimulation has a very important role [17], especially for sports organizations of the system are essential []