I used to cycle regularly 1 year ago. Then I switched over to motorcyle and completely stopped bicycling for an year. Over this time I have become obese and developed a huge pot belly. For exercise sake, I recently started cycling again. I feel very tired after cycling, and an unbearable temptation to go to bed. And when I get up in the morning I still feel somewhat tired and not as refreshed. Also I sometimes have a headache right when I get up. Why does this happen? Is it due to my obesity ? Could the fast movement of my legs be causing too much shock to my waist and belly area and induce body ache ?
Headache often equals...dehydration.
Beyond that, general physical condition could have a lot to do with it...not to be unsympathetic. Eventually, healthy eating and more cycling will catch you back up with everything.