I agree the water consumption needs to be looked at. I found that by drinking about five pints a day not only do I feel less tired but it also stopped my muscle cramps.
This may also be linked with cutting out tea and coffee, low manufactured sugar consumption, I take the sugar from fresh fruit.
Less booze
Agree about the swimming We invested in a swimspa about four years ago which is indoors and is used every day. You swim into a powerful current.
Cut out general vacuous TV and select a program to watch if you must. Better to learn to play a musical instrument and use the time as a form of meditation.
Limit computer time
Pack up earlier and go to bed early.
I would strongly advise against a nap in the day as it means the sleep will be lighter at night.
Good pillow and mattress, quiet bedroom and a wife/partner that does not involuntarily kick in the night
Medical checkup for diabetes or other problems
All this might sound like a recipe for creating a boring old fart, but there is not much more boring than being around someone who is tired all the time. Perhaps short tempered with the tiredness.
As you become older you become weaker. Although I look fit and much the same as I did when I was twenty five apart from the hair loss, I cannot lift the two 56 lb weights above my head which I used to do with ease. Hopefully by the time you are in your sixties as I am you will have established your business enough to delegate much of the harder work and have earned enough to give yourself the breaks you deserve after a hard working life.
If you read the thread on sleep started by Gray you may just find sleep by reading Arbtalk posts!
Your eyes are becoming very heavy, you are becoming very sleepy, you need to lie down, you feel a great weight....................