UKH

Hi, I've been running for over 12 years, mainly 5K to 10 miles and thrown in a few HM trail runs.

I've recently decided to get more serious on HM trail runs and was wondering, can you pace predict these runs. No race is the same, so I normally just run by feel, speed up and slow down according to the terrain.

I have a race in 5 weeks (Penshaw HM) the last 1km is all ascent, so my thoughts are make time up during the main race, as I know I'll slow down considerably on that last 1km climb.

Would be nice to hear any advice, Thank You

Fast start, slot into your other runners running at your pace, eye balls out for last 2k to beat them.

Feel crappy on the finish line and great on reflection.

Perfect race strategy in one short sentence.  

Or start steady,  speed up and enjoy the rush of passing all the clowns that went off too hard.  

That's more like it!   

Not looking forward to the 20 degree plus climb at the end.

On the Garmin watches, at least the posher ones, there is a PacePro function which I have used once on an Ultra to try to slow myself down at the beginning. It takes your expected time, considers the splits and asks whether you go fast or slow up hills. The race didn't go that well (I think I need to accept that I am a positive split kind of runner and I was trying to fight that) but what it was suggesting felt about right in terms of differences in pace on hills, descents and on the flat.

On the web when planning this, the possible paces were ridiculously fast for me and the terrain, but once on the watch I could alter that to meet my needs to stay on track.

This may be irrelevant, but it looks as if the tech is out there to try to optimise peoples pace on these vary variable races.

Very interesting, Garmin do seem to have never ending features.  I did use my Stryd software to look at this run and it was claiming I can run up a 15 degree incline at 5:20 km pace, no chance!!!

I think for this race it will be all on feel, trying to save some energy for the last killer 1km.

I've had that new watch itch for a few weeks now, but can't really find a watch that justifies the expense over my old Polar V-800. 

Do you have a heart rate monitor (chest strap not wrist based)?

I'd be minded to ignore the last km when planning, start steady and push it towards the end ... and then just accept the last km will be hell but it's only a km.

Always my plan but end up starting too fast and hanging on for dear life. Thankfully manage to control myself on marathons but have had some pretty unpleasant 10km to HM experiences. 

Yes, Heart rate belt, I still run with a V-800.

Thanks, that's sounds like something I could do. I don't have access to hills that steep near me anyway, so can't actually simulate that last 1km.

It's so much nicer to haul places in on the second half of a race than see people come past you and there's nothing you can do about it. Think about as bank account, once you go too overdrawn you start racking up charges and the wonder of compound interest means it much cheaper to do this towards the end

I'd run using % of max heart rate, say stay at 85% and then throw the kitchen sink at the final 2k. 

Personally I'd be looking to hold some back but to some extent it's a maths question.

There's a 1km/ 100m hill behind my house. At a steady run it takes 7 mins. At a walk it takes 12 mins. At the end of a half marathon, the range of times is probably somewhere between these times. So would going flat-out for the previous 20k and taking 12mins for the climb be quicker than going steady for 20 and then 7 for the climb?

Anyone's guess!

On reflection, the maths question shows that the difference in pure time isn't huge, unless you're in contention for prizes :-D 

What would you enjoy the most? Feeling strong and powering to the finish or crawling over the line after walking up the hill?!

Thanks for the info and to everyone who has posted. As this is my first HM for a few years, I'm going to run by feel, while keeping in mind the information and advice you guys have given.

If you're into racing, there is a limited amount you can gain by incremental improvement.  At some point you have to throw your hat in the ring and go for it, preaccepting the consqequences might not be pretty

I was going to say something similar (and similar to rob-hutton). Racing is different to running a pace or for a time. If you want a time or to run a pace then try some of the suggestions like using a HR monitor or winding it up through the race to overtake people. The latter makes you feel good but you're unlikely to run as fast as you're actually capable of doing. If you want to race hard and try to run to your potential you have to commit from the start. Go hard at the start, settle in with a group of similar speed (if there is one) and hang on. If you get it right you'll run to your potential, if you don't you'll hit the wall and blow up (too many metaphors?) (lactic build up and slowing down because you've gone into oxygen debt). I've done both and when you get it right it's much more satisfying the running to a pace or coming through the field. When you get it wrong it's horrible! It's a hard way to run but it's "proper" racing. When you've tried it a few times you get used to it and get a feel for your starting speed and will get better at it. If you're finishing really strong you've got it wrong and have more in the tank and could have run faster - you should be hanging on for dear life, unless you're the winner of course. The interesting thing is that if you try this method and it works you'll find that your position in the race changes very little after the first couple of miles. Very few people will come past you.

Totally agree with this - it's also a really good test of fitness. When fit my position in fell races is usually set after 2km and doesn't change much. When unfit (now!) I drop places towards the end as my head is faster than my lungs and legs.