Help - Half Marathon Pacing Tips


I have just run my 3rd half and was really disappointed with my performance of 2hr 15sec. I am really struggling to crack the pacing for the distance and know that I should be able to achieve close to 1hr 50min.

I seem to have got into a cycle of running the first 6 miles in about 48 mins, and then running on empty from about mile 11.

I do 10ks in 50 mins and hope to go sub 50 this year. I do 10 mile races in 1hr 24 mins. In addition to this I am training up for a marathon and have now got my long runs up to 15 miles, and taking about 2hrs 30min.

Some of the problem is probably mental. For example on my last half I was still comfortable with the pace at 6 miles but when I checked my watch, I went into the 'oh no - too fast' attitude and then did mile 7 in 10 mins. managed to pick up the pace but hit real problems again at 11.

I do not have a training/running partner and am not in a club. I have one freind who runs some races with me but she is really fast and competitive and tends to use me to score points off and boost her ego - which probably does not help me. Come to think of it, I do better int he races she does not do!!

Any advice, hints etc gratefully accepted.


  • 9 minute miling would be the key I reckon FB!

    I am about your pace- my 10k pb is 51:07 and my half marathon pb is 1:55:35. Consider running some shorter races at 9 min mile pace, don't go faster, use the mile markers to get a feel for that pace.

    Keep existing training going, enter 1/2M and run at 9min mile pace for 13miles. Result: sub 2 hr 1/2M.

    Otherwise: join running club for company and inspiration, use gels on longer runs to lose the empty feeling.

    Im not an expert, just a few ideas that have worked for me!
  • Er... go slower? ;-)

    I'm about the same speed as you for the shorter stuff - 49 & 1:20 - but 1:47 for the half. And 8 min miling early on is too quick - only by 10-15 sec, but too quick anyway. By the time you did a slow mile 7, the damage was already done - you'll still be paying off mile 1 at mile 13.

    You're absolutely right - you should be capable of 1:50, but you have to throttle back really early on, probably earlier than you suspect.

    Of course, if you're not doing enough miles in training (a long run of 13-16 miles, and maybe 25-30+ miles total), or not hydrating properly, you may suffer anyway.
  • Swerve is right FB. Its the pace early on that is the key. Just sacrificing a couple of minutes in the first half equates to a drop in pace of 20 seconds per mile which should feel really comfortable. You should then have plenty of energy in the bank to keep going for the full distance at an even pace if not slightly faster.
  • can I ask ...while this thread is going... what I should aim for in blackpool on sunday. My 10k is still only 59:30 but hoping to lose a fair bit off that as my weight drops. I don't actually know what time to expect or what to pace myself at really. So far a very hilly 10 miles has taken me 1h 57mins. Any advice gratefully's my first half..

    Sorry to but in on your thread FB....
  • FB... ditto what others have said about not going off too fast.Your other times are similar to mine and I did a 1/2 in March in 1-52 and felt comfortable.. Try not to make this a mental/ panic hurdle.. You just need to 'tweek' your trainig and pacing. I joined a running group this year and it really has helped with speed work and confidence.. also knwing when to push the speed a bit. Try to keep an eye on your split times and aim for even splits in first half of race.. working towards faster splits in 2nd half.. Also don't forget the basics.. are you eating enough and well hydrated??
    Good luck and don't worry!!!!!
  • GavoGavo ✭✭✭
    FB, I'd recommend (as others have) starting more slowly - 8:30 - 9:00 min miles for the first 4. I think that this may help in keeping your stamina for the later part of the race.

    I also break races down into halves so once you have got to 6.5 then you can count down - only 6m, 5m to go etc. I'd also recommend, if you can in this weather, doing a few easier 1/2s if you can find them.

    Taking on some fuel halfway could also help - either energy gels or sweets or whatever works for you.
  • FB: They are all correct, go slow early.

    You have to teach your body the pace you want to run at. I would suggest you measure a flat course and mark the miles, then try to run each mile at about 8:45.

    Before you start the traing run do whatever pre-race warm-ups you do and then go out. Settle into a rythm and assess how your body feels. Keep adjusting the pace until you can 'feel' the speed you want. It takes a while to get there.

    I know for myself that the paces I can run at are:
    5k - hurts all the time. Can't talk
    10k - just uncomfortable. only a few words
    10m - very, very slightly unconfortable. can say single sentences
    1/2m - comfortable. You can run and chat
    marathon. - easy, do knitting and run at the same time.

    Good luck, you'll get there
  • MTDRF,

    Great advice - I wish I'd followed it myself at the weekend.

    The only problem is that the first mile of a marathon or half-marathon often seems really easy, and it is not until you look at your watch that you realise how much you've pushed it. And by then the damage is usually done - according to most sources a fast first mile is by far the most damaging.

    I think that for these distances it is definitely worth forcing yourself to run very slow for the first mile after which you should be able to gauge your level of effort better.
  • Everyone,

    Obvious really!
    I managed my 10 mile 1.24 time by doing steady miles, but have not been able to do it since. It is all about dicipline really, and a need to get it sussed for the marathon.

    At the moment I am doing about 30 miles a week in training made up of one long run and shorter ones.

    Hydrating is a problem. I find that I need to pee a lot before races (nerves)and so can't take a lot on board before hand, and then find it really difficult to actually drink from a bottle and run, so am going to experiment with a camel back.

    My diet is good. I love food and cooking and have a couple of really good books.

    I do some training on a treadmill, which I had hoped would help teach my body what different speeds feel like. I suspect that I just get carried along with the crowd at the beginning of the race, and as you say the damage is then done.

    My next half is August 3rd, and I really want to try and get that one right.

    Is there anyone on the south side of Glasgow looking for a training partner??
    I have'nt plucked up the courage to join my local club yet (Giffnock North).
  • Hi freefall, everyone else have pointed out the things to help with your pacing. One thing I found very helpful for 1/2 marathons was building in regular tempo runs at 1/2m pace in the 2 months beforehand. I would usually run an 8 mile loop, 1 mile warm up and 7 at my target pace. I used my hrm to make sure I stuck to the right effort, and measured the overall loop (never bothered measuring the exact mile intervals.)

    By the time the race rolled around I was so familiar with how my pace should feel it was much easier on the day.
    By the way, unlike Mak the dog, I wouldn't describe 1/2m pace as comfortable! But it shouldn't be back-of-the-throat burning either.

    Good luck.
  • freefall - thanks for bringing up this question -

    I'm slower than u but it sounds like I have EXACTLY the same problem. My 5k times etc predict a 2:07 halfmarathon, and I still can't crack 2:15!

    My symptoms are like yours, and I was beginning to figure out that it was all about the early pacing mistakes - the replies on here make so much sense.

    Now to go away and practice better pacing...

    ....but my next half is on Sunday - EEK!

  • Laura,

    how do you find your target pace for a 1/2M? Thank you
  • One way of doing it Awww Spud is, using a race calcultor (sorry no link) to find your predicted finishing time, working this pace out on a treadmill and then as Laura says find out your HR for this pace by running on the treadmill and then run at this HR in training.
  • Laura, Pizza Man et al,

    I like the HRM suggestion, especially when used in conjunction with the treadmill. It never ocurred to me to use the HRM to set my effort on the road based on the treadmill rate. Doh!

    It creates a purpose for using the thing too.

    I have 3 weeks of holiday coming up before my next 1/2, so I was hoping to use that time to really try and get the pacing sussed and to push my distance on for the the marathon.
  • Easy early on is the key . Nine minute miles for the first few miles and then you can pick it up. If you can't pick it up you are still inside two hours by over two minutes.
    Your 10K times however suggest much faster.
    Have a good holiday and fly it when you come back.
  • There is a formula for predicting your time! I hope you are good at maths

    PT = predicted time
    PD = distance of the event you want to predict for
    KT = Known Time for a Distance
    KD = The Known Distance

    PT = KT x (PD/KD) ^1.07

    where ^1.07 means raised to the power of.

    For me there is less that 1% error for all my PBs from 5k to 15miles.

    The formula is inaccurate for events of less than 2 minutes or longer than 3 hours.

    email me if you want the formula in an excel spreadsheet.
  • Either slow down at the start by 20 - 30 seconds per mile (short term solution) or train so you can keep up the pace for the half marathon (takes longer).
  • In another thread If found a link to a pace calculator!
    prediction calc
  • Mak, yes that is a useful site but if you go to the first page there are other useful calculators such as comparing performances at different ages. Try it, its fun.

  • So let me get this straight....

    Do 8.30-9.00 minutes miles up to, say, mile 5, then pick it up? What pace would you suggest to pick up to and would you pick it up even more on the the last couple of miles?

    I have done my recent 10ks in May in 51:00 and in March, I was amazed I got a time of 1:54 for my first half marathon, when I was expecting a time well over the 2 hour mark. I can't quite believe that based on my 10K pace that I could, in theory, achieve a 1:50 H/M time. Very interesting!!! I'd die of joy, if I could get a something near the 1:50 mark. :0)

    So does this negative split thing really work? My next two H/M's are in September, so I'd like to try this out, if it's the way to go...



  • well I am going to give it a go, cos it seems to make sense, and I am really frustrated with my current performance. But it is going to take a lot of dicipline at the start.

    I also, accept the value of the comment about extending the training to ensure that I can keep up the quicker pace, but I suspect that will come gradually over the months, especially as I train on.

    The key thing at the moment is to ensure that I am performing at optimum based on current training.

    My 10ks have really developed well over the last year. I have knocked 6 minutes off last years PB, by increasing the training and running at an even pace. I just need to adopt the same tactic with the halfs. The 10ks are probably the root of my problem, in that I am trying to run the 1/2s at 10k pace, probably because I have more xperience there and have been doing them for longer; and have put quite a lot of focus on them, without thinking of the impact that has on the longer distances.
  • Angela, negative splits do work. good luck, go for sub 1.50! (if one of your 1/2s is the GNR, don't be too disappoint ed if you don't, it's too crowded). Once you set off too fast you're in energy debit for the rest of the race.

    Re use of hrm, I used it for all my training and racing and so got an idea of what my training ranges should be.
    For me, a 1/2 m effort equates to about 85-86% working heart rate. So I made sure my tempo runs were run at 80-85% (at the lower end of usually).
    I set my 1.45 target on the basis that my previous pb was 1.51, and it sounded like a good number!
    As my training went on, the pace I was running the tempo runs got faster, and I did one time trial of 10 miles 2 weeks before the race at my target pace on a flat route where I'd measured the mile markers previously.

    So by then, I knew running at 85% would get me a min/mile pace of about 7.45, which is exactly how it worked out in my race, got 1.40 (watch time). Unfortunately it's been downhill ever since!

  • My message crossed with yours freefall. Just for comparison, my 10K race effort is about 93% whr. If I set off on a 1/2m at that effort I would die a death about half way!
    Try wearing your hrm in your race and make yourself stick to the level you've set. Experiment in your training (on the road, inside the readings might not match what you'll experience outdoors) and work out your target effort levels.
  • FB: Using a HRM may add another complication factor to your runs, its a matter of indivdual preference. I tried for nearly a year to run with a HRM, and I didn't improve. I could never get the % figures calibrated for a race. In the end I ditched it and now I just run at the perceived levels of effort.

    The advice to make the 1st mile really slow is really good. I usually try to start further back than my predicted time because:
    a) you are held back over the 1st mile as the field spreads out.
    b) you get to overtake a few people, which is a confidence boost.
  • Once again, I completely agree with MTDRF:

    I arrived late at the GNR a couple of years ago and had to start much further back than I wanted. However, this turned out to be a god-send. My first couple of miles were way below my intended sub 1:30 pace because I was boxed in by the weight of runners around me (I think I ran a 9-minute mile followed by an 8-minute mile). However, once I got some clear road ahead of me I was then more than able to make up the lost time and finished in 1:27 feeling much better than usual...

    Also, it was a fantastic feeling to be overtaking people along the way. This definitely gave me a real boost.

    A useful tip in training is to try and increase the pace for the second half of your long runs. This should help get you used to running a negative split.
  • I have only run 4 halfs now but my first was in 2.07 and the most recent in Sheffield (which is a tad hilly) was a PB for me in 1.47. A couple of things really helped me get quicker and one is starting slow as everyone else seems to be saying. I ran the first six miles saying to myself over and over again 'keep something back' like a mantra and I would test myself every mile or so by accelerating past someone and slowing back down again just to ensure i was holding back and judging it by how easy it felt to overtake. Being quite bad at pacing myself I found it helped me know what i had left by how easy I felt it to accelerate - might sound like tosh but it helped me.

    The second thing was speedwork which i now do every week. I hate it but it works ;)
  • Laura, it doesn't sound like tosh - it sounds spot on.
    You seem to be doing everything right. I wish I could.
  • So lets see. If my 10k is 59:30 using the calculater suggests a half of 2h 16

    Thats miles of 10:46

    How much slower should I start, and then pick up by. I assume if you start TOO slow making up the time ceases to be an option as you are to far back to make it up.
  • you could time a few shorter runs at a quicker pace that you can sustain to give you an idea of how fast and more importantly how long you can sustain them for then you could use these times to work out what is practical in terms of what you think you will be able to make up.
  • Snail,
    I may be wrong but I think a 2-16 half is about 10-23 per mile not 10-46.
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