Yepthatsme,
You might try fast walking in the morning and slow strolling at night. I was a lifetime walker until lately and subscribed to several walking magazines.
Most authorities agreed that fast walking stimulates metabolism which can keep you awake if done at night whereas a slow stroll can be relaxing.
Fast walking in the morning gave me energy for the whole day and kind of organized my mind, but it kept me awake or awakened me if I did it at night whereas slow strolling relaxed me and I would be tired enough to sleep.
Might be worth a try.
smile