I usually run in the evenings after work (as the thought of getting up earlier in the morning horrifies me!) and after the post run endorphin fuelled high has worn off, I'm really tired and really exhausted the next day.
I guess my body is still adjusting to all the extra effort being put into this relatively new exercise plan (I'm on week 5) and I am watching my calories - so there are fewer going in, but shouldn't I have more energy by now?