4. According to Harvard psychiatrist John J.Raety, M.d., coauthor of a book on psychological disorders called Shadow Syndromes, a single workout can raise your brain's levels of antidepressant chemicals, such as dopamine, serotonin and norepinephrine.
5. If you are feeling down, exercise may help pick you up. Although researchers disagree on this issue, one review of past studies found that long-term exercise, especially when it includes long-lasting, strenuous training sessions, has about as much of an effect on depression as psychotherapy. ( Of course, this doesn't mean you shouldn't seek therapy. If you believe you may be suffering from depression, the first thing to do is to consult a mental-health professional. )
6. Working out helps you deal with stress in your job, relationships or any area of life—possibly because exercise is a form of stress itself and helps condition your body to deal with it. When Australian researchers compared people who did 30 minutes of aerobic exercise three times a week to those who practiced progressive-relaxation techniques, they found that the former group responded better to acute stress and had lower blood pressure.
7. Even a little exercise can make you think less anxiously, Studies have shown that any amount of exercise, from a brisk 10 minute walk to an intense aerobics or weight-lifting session, seems to decrease feelings of anxiety.
8. Aerobic exercise may make you think better. Over time, cardio exercise (coupled with a healthful diet) improves the flow of blood that carries oxygen and nutrients to your brain.
9. Working out regularly may make you smarter now and lessen the possibility that you'll lose brain function as you age. According to a recent animal study at the University of Illinois, exercise can actually help the brain develop new cells.
10. In several studies, regular weight training or aerobic exercise was shown to improve the quality and duration of sleep. Naturally, this can make you less fatigued and be able to function better during the day.
11. Like meditation, hobbies or any other leisure activity, exercise gives your mind a needed break from everyday thoughts, responsibilities and commitments.
Finally, there's one more reason to keep exercising. When you work out regularly (but don't overstrain), your body simply, functions better—you are better, healthier and less likely to suffer painful physical conditions. And that just plain feels good.
众所周知，锻炼有益于身体健康。但是，许多人并没有意识到锻炼对智力也有好处。当然，我们不是说，练习举重会一下子把你变成另一个爱因斯坦——研究表明，有规律的锻炼能改善心境，提高自尊心，甚至增强大脑的功能。
就像身体和头脑在健康方面的其他关联一样，科学家们开始了解到，锻炼身体为什么能提高智力、改善情绪，但也知道了更多的可能性，新的研究还在继续进行。对于那些致力于促进头脑和身体不断发展的人，这里有12条新千年开始锻炼计划的附加理由。
1．锻炼能给你带来愉悦和成就感，并且，做某件明知对自己有好处的事，会增强你的自尊心。
2．锻炼会使身体分泌内啡肽，这种物质能缓解痛苦，有助于产生所谓的运动快感。
3．练习举重最能提高你的睾丸素水平，这样有助于心境的改善，尤其是如果你的睾丸素水平天生较低。
4．哈佛大学精神病医生、医学博士约翰·瑞特是一本关于精神错乱的、书名为《影子综合征》的合著者。他认为，一次锻炼就能提高大脑中抗忧郁物质的含量，如多巴胺、血清素和去甲肾上腺素等。
5．如果你情绪低落，锻炼能帮助你重新振作。尽管科研人员对此并非一致认同，但有一份回顾过去多种研究的报告表明：长期锻炼，特别是长时间持续进行的高强度训练，对治疗抑郁症的效果，同心理治疗几乎一致。（当然，这并不意味着你不应该寻求心理治疗，如果你觉得自己遭受抑郁症的痛苦，咨询心理健康专家是首要之事。）
6．锻炼能缓解你的工作、人际关系和生活中其他方面的压力——可能是因为锻炼本身也是一种压力，有利于自身调节。澳大利亚研究人员作了这样一个比较：把每周做三次30分钟有氧健身操的人与进行逐渐放松练习的人作比较，他们发现：前一组更能承受较大压力，血压更低。
7．即使是少量的锻炼也能减轻你的焦虑。研究表明：任何强度的锻炼，从10分钟的散步到剧烈的有氧运动或举重练习，好像都能减轻焦虑。
8．有氧运动有助于思考。日积月累，心脏锻炼（加上健康的饮食）会改善血液循环，给大脑输送更多的氧气和营养物质。
9．有规律的锻炼可以让你思维敏捷。大脑功能随着年龄增长，日益退化的可能性也随之降低。根据伊利诺伊大学动物实验的最新研究，锻炼其实有助于大脑产生新细胞。
10．多项研究证明，有规律的举重练习或者有氧运动能改善睡眠质量，增加睡眠时间。自然，疲惫感也会随之减少，白天的工作会更有效率。
11．如同沉思、爱好或其他休闲活动一样，在日常思考、承担责任和义务之余，锻炼会给你的大脑提供所必需的休息。
最后，还有一条坚持锻炼的理由。当你有规律地锻炼时（但不要过度），你的身体一定会更好——更强壮、更健康，更少遭受疼痛，那种感觉好极了。
早睡早起会使人健康和聪明。
millennium [mi'lenim] n. 千年期；千禧年
What does a millennium mean to you?
一千年对你来说，意味着什么？
exhilaration [i,zil'rein] n. 愉快；令人高兴
I felt the strangest sensation of fear and exhilaration.
我有一种既害怕又快乐的感觉。
psychotherapy [,psaiku'erpi] n. 心理疗法；精神疗法
The doctor said that she needs psychotherapy.
医生说，她需要心理治疗。
aerobic [,ei'rubik] adj. 需氧的；增氧健身法的
She started aerobic classes to build her endurance.
她开始进行有氧课程来增强她的耐力。
许多人并没有意识到锻炼对智力也有好处。
做某件明知对自己有好处的事，会增强你的自尊心。
如果你情绪低落，锻炼能帮助你重新振作。
But study has found that working out regularly improves your mood.
work out：算出；制定出；解决
Researchers disagree on this issue, one review of past studies found that long-term exercise.
disagree on：对……持有不同看法