I'll bet you are sleeping well after all that fresh air and exercise. For myself, I find that the "tired" after 8 hours in front of a computer/at a desk and the "tired" after 8 hours working outdoors are completely different feelings. After long hours at a desk, I feel "bad tired", exhausted and stupid. After long hours of physical exercise, I feel "good tired"...relaxed and mentally sharp.

Exactly how I feel about the different kinds of being tired After all those years of office work and commuting and being mentally tired, it is so refreshing to be physically tired!