Let me say right away that I'm in my very late 30's ... ok I'm 41!, and extremely unfit. The good news was that I realised I had to make a change so I started C25K two weeks ago, knowing that I'd have to repeat some weeks due to my lack of fitness, and that was ok, I accepted that. The problem is that I have just completed my 5th run from week 1, and I feel like I am going to die. My legs feel like lead weights, lungs on fire, and I was almost dragging my knuckles across the floor on the last run. Why does this seem to be getting harder not easier? The 3rd & 4th runs were far easier in comparison. I'm drinking plenty of fluids and try to keep to a schedule for my runs (using a treadmill), but this morning was really really disheartening. I WILL stick at it (as enough is enough), but can anyone offer me any advice as to why I feel that this is getting harder not easier? And any other tips in general. Thank you.