Why Do Athletes Chew Gum While Playing?
athlete：运动员，田径运动员，擅长运动的人；
Chew：咀嚼，嚼碎，（因为紧张）咬住，（为尝味道）不停的咀嚼；
Gum：牙龈，树胶，齿龈，树脂，口香糖；在……上涂胶，用黏胶粘；
为什么田径运动员会在比赛中嚼口香糖？
Who would have thought that chewing gum affects cognition, but studies have a link between chewing and brain function.
cognition：感知，认识，认知；
谁能想到嚼口香糖会影响认知，但研究发现，咀嚼和大脑功能之间存在联系。
When we chew something, the receptors in our mouth that sense taste and pressure from the jaw movements start firing and sending electrical signals to the brain. These electrical nervous system signals move to the brain, which works to understand these signals. This added brain activity places the mind in a more alert state, which is why focus and concentration are improved.
receptor：受体，感受器；
jaw：下巴，下颌；
nervous：神经；
concentration：专心；集中；浓度；
improved：改良的；改进过的；
当我们嚼东西时，我们嘴里感受味觉和下巴运动的感受器，开始向大脑发送电信号。这些电子神经系统的信号转移到大脑，大脑负责理解这些信号，这增加了大脑的活动，使大脑处于更加警觉的状态，这就是为什么专注和的注意力都得到了改进。
Additionally, increased brain activity means more energy for those mental metabolic processes, so blood flow to the brain also increases while chewing. The greater blood demand from the brain makes the heart beat quicker so it can supply what is needed.
additionally：另外；
metal：精神的，心里的；脑力的；
metabolic；新陈代谢的，变形的；
demand：要求；需求；请求，需要；招唤；
另外，增长的脑部活动意味着为精神新陈代谢过程提供更多的能量，因此在咀嚼时，向大脑的血流量也会增加。大脑更多的血液需求，使心跳加快，从而提供所需的血液。
To sum it up, chewing activates the receptors in our gums that send information to the brain. The added bonus of an increased heart rate also allows the muscles to receive more bloods.
sum……up：总结，概括；
bonus：奖金，红利；意外收获；
总结一下，咀嚼激活了我们牙龈上的感受器，向大脑发送信号。心率增加的好处也允许肌肉能够接收更多的血液。
So now you may be wondering... does this mean that the harder you chew, the better the focus levels? Yes... to an extent. Chewing harder gum does boost attention more then softer gum. Similarly, chewing flavored gum is better for cognitive functioning, as it activates more receptors in the mouth than chewing flavorless gum.
to an extent：在（某种，一定，很大）程度上（范围里）；
boost：使增长，使兴旺；提高，增长，帮助，激励；
flavor：风味，滋味；给……添风味；
cognitive：认知的，感知的，认识的；
functioning：动作，运行；
因些，现在你可能会好奇，这是否意味着你更用力的咀嚼，专注力就会更好？是的，在某种程度上。用力的咀嚼比轻柔的咀嚼更能提高注意力。同样的，咀嚼有味道的口香糖更能对感知功能更好，因为它此咀嚼无味的口香糖激活口中更多的感受器。
This is why so many professional footballers and basketball players chew gum. They think faster and it speeds up their actions and reflexes.
speed up：加快速度；加快；
reflex：反向动作，本能反应，反向作用；反制的；
这就是为什么很多专业的足球运动员，蓝球运动员嚼口香糖。他们思考的更快，这也加快了他们的行动和反应速度。