调查者发现每天散步有利于睡眠质量。他们同时也提出只有早上锻炼才对晚上睡觉有利。那些晚上锻炼的人实际上有更多的睡眠问题。一个可能的解释是晚上和早上锻炼相比会影响睡眠质量。早上锻炼可能会让生命钟变得有序，而晚上锻炼则会打乱这种秩序。但是还需要更多的调查来证实这

I am here tonight to wish your club a happy birthday. Now, I myself have reached that stage in life where I like to have my birthdays remembered but not my age. I suppose I am what is called middle-aged, which is when you start eating what is good for you and not what you like. I am proud of your club because it is set up for our senior citizens. This is a place you can come to for peace and quiet, where you have tea and chat with people of your own age group.

Researchers have found that daily walking may improve sleep quality. They have also noticed that only those who exercise in the morning have the beneficial effects on sleep. Those who exercised in the evening actually had more trouble falling asleep. One possible explanation is that morning versus evening exercise may affect sleep quality. Morning exercise may get the body clock in good order, and evening exercise may upset it. However, more research is needed to confirm this theory.