The human body needs a certain amount of sleep to function properly. The rest period changes throughout the lifetime. At birth its the highest with a baby liable to sleep for 20 out of 24 hours. It decreases gradually and becomes stable at 7-8 hours. Through most of a person’s active live, 8 hours of sleep is enough and at older age(>60) when physical activity has come down even 6 hours of sleep would be enough.
Of late(last 20 years or so), going to bed late and getting up late has become norm. Synchronizing your body cycle to the Sun is a good practice and helps you give a head start compared to others who get up late. Its a loss to waste the daylight hours sleeping(unless your profession demands like you are working in a different shift etc). By the time its 2 to 3 hours post sunset the human mind is already winding down and operates at a reduced start of activity and alertness.
Human beings have evolved over time. The first human beings appeared around 2.5 million years ago. Out of this 2.5 million years, we have had electric light for less than 150 years. So its safe to conclude that our biological clock is tuned to operate along the time cycle of the Sun.
I am not advocating sleeping less. Just go to bed early and get up early. You can give this a try and see for yourselves if what I advocate makes sense. But you need to do this for 7 consecutive days to feel the difference. Sleep for no more than 8 hours and go to bed before 10 PM compulsorily. Try it out !Yamaha Receiver RX V457 »« Benfish stall at Karigori Bhawan