I've recently finished c25k and I'm mow regularly running 5-6k. Since the weather has improved I've ventured off road - into the hills and woods near us. The terrain is much steeper and rougher under foot and I've found I'm running more slowly. This might be due to the hills which I'm sure will get better with practice ! but should I expect to be slower on more uneven terrain? I was running 5k in about 31-32 mins. Now I'm managing 4k in 30 mins. It's quite demoralising.
Any advice?