Human studies have focused primarily on older adults and suggest that regular exercise can improve the speed with which the brain processes information because declines associated with aging could actually stem from declines in fitness. Some scientists speculate① that reduced mental functioning often attributed to aging may be the result of a sedentary② lifestyle and related factors such as medications and poor nutrition.
Children who engage in regular physical activity do better in school than their sedentary classmates. But until recently， the academic edge conferred③ by sports participation was thought to come from the increased self-confidence， better mood， and the ability to concentrate that come from burning off steam in exercise. Now， however， some scientists point to possible physiological connections.
Aerobic exercise increases the amount of certain brain chemicals that stimulate growth of nerve cells.
Inactivity may also have detrimental effects on mind and body alike. Cognitive④ scientists recognize that mind is body， and body is mind. The most beneficial forms of exercise is to engage both.
① speculatevi. 思索；沉思；推测 vt. 推测，推断
② sedentaryadj. 坐着的，需要(或惯于)久坐的；(鸟等)定栖的；(贝壳)固定附着的
③ confervt. 给予，赋予 vi. 商谈，协商
④ cognitiveadj. 认知的；认识的
锻炼使你更聪明
对人类进行的研究主要集中在老年人身上，这些研究表明，经常锻炼可以改善大脑加工信息的速度。因为与老年有关的种种衰退实际上可能是由于健康衰退。一些科学家认为，人们常常把智能的降低归因于衰老，而智能降低可能是案牍生活以及诸如药物和营养不良等相关因素造成的。
经常参加体育运动的孩子比他们那些不爱活动的同学在学习上更出色。然而，直到不久前人们还认为，参加体育运动之所以会带来学习上的优势，是因为在运动中消耗精力的时候一个人可以增强自信心，改善情绪，集中注意力。可是现在有些科学家指出，有可能是生理上的原因。
增氧健身运动会增加某些大脑化合物的数量，继而刺激神经细胞的增长。
懒散也有可能对身心产生不利的影响。认知科学家们公认心就是身，身也就是心。最有益的锻炼方式就是对心身两者都进行锻炼。
