Average pace

I dont think you can compare the two. You will go out there, with an agenda in mind, but your body will tell you something different to what you want your body to do. I think you should just run the first mile, and see what feels comfortable, then take it up a notch if it feels right. Be in mind as well, that the way we approach hills and downhills with our running, is going to be different to how you run on a flat. It might take a little adjustment to begin with...

tony thorpe wrote (see)

normally would someone make back there time going downhill after running up?

No.

Running downhill you've got gravity on your side but it's not like freewheeling on the bike; every time your foot hits the ground your muscles are actually working as brakes to stabilise you, so running up and down, on average, is much less efficient than running on the flat.  So you will be able to run a quicker average pace on a flatter course.

No you will not catch up the time on the downhills, that's why people look for flat courses to do fast times. You should usually be faster on a flat course.

However, a word of caution. When you run downhill you do get a break, and a chance to recover, on the flat it is constant grind. If all your training has been done on hilly routes you may find it feels quite challenging to run 13 miles on flattish terrain. Although I live in a hilly area, and think I do benefit from extra strength from them, I try to include some much flatter runs regularly in my training so I am used to the flat as well.

You'll just have to go and see - may well find it much easier and a bit faster, but don't be suprised if not. Remember the crowds of runners will slow you down (unles syou are right at the front or the back) & don't waste too much energy dodging round them in the first few miles.

Give it a go Big G!

Running on the flat is definitely quicker, just doing go in expecting it to be dead easy. Think it was Greg Lemond who said "It doesn't get any easier, I just get faster." 

You'll definitely be faster on a flat course. By way of example we have two parkruns in the Glasgow area, one hilly and one flat and most people are up to a minute faster on the flat one.

I go on effort, rather than pace. I too train on quite hilly routes and my races are often quite a lot flatter than my training is so on race day I will try to run based on the percieved effort. If, on race day, it all feels very easy, because you're on the flat, then you probably have some room to up the pace a notch or two. If you find you're struggling, you've probably been lulled into going out too fast by how flat the course is, so will need to slow down.

It's a cliche but, listen to your body.

Big_G: I'm the same. I have a flat 10K race on Sunday and am aiming to run about what your PB is. All my training is on hills, so I've not got anywhere near that time on training runs and neither have I expected to (or tried to). I am hoping that the flat course will give me the help I need to make that time.

Running Rodent wrote (see)

Tony - a word of warning - you mention 'all the energy gels' helping you on the day. Have you been using these gels in training? It's really not a good idea to try out gels under race conditions, or to increase consumption beyond what you're used to. If you discover on the day that they don't agree with you, there can be disastrous consequences for the digestive system. If you haven't tried them before, I'd forget about them on the day - you don't really need them for a half marathon.

I agreed with Rodent. Gells are very individual and i have known enough people who have been sick on them, to tread the water carefully. I take them, but no more than three in a half marathon, and i think it is partly, in the head, you think they are going to work better for you. I take the zero tablets which i feel work better since stabilise your body better.

I don't take any in a half.

unless it's a hot or humid day, no real need to take fluids in a half either, unless you're running for 2hours or so.

How did it go?

I love the way you start by saying it went really well, your time and your plans for the next one before casually dropping in that you're in a and e!

Good time though, well done.