Half Marathon - not quite lasting the distance

Hi all

Done a number of half marathons in past and always folloed the advice of never running more than 10 miles in training as no need to do full distance to be able to run a half marathon. However every time I seem to lose all energy in my legs in last couple of miles and slow down. So to me logically I would be better over training - say one 15 miler every month - so that the HM did not come as such a surprise to my legs. It is my thighs that seem to die on me.

Also I've always thought that training for a distance you need to train about double the distance every week in total - so for a Half training would be about 26 miles per week - perhaps this is also too low?

Any advice would be appreciated - I'm trying to run a HM in October in sub 1:35 - curently running about 25 miles a week and my 10 mile training time is about 77 mins, 5 mile about 35 mins (flat out).



  • Thanks - I've been running (this time!!!!) for about a year - does that make me a non beginner?

  • Absolutely go over the distance in training to improve your stamina for HM! As an extreme example (and I'm not suggesting you do this), after I'd trained for and run a 50K, I set off on my next HM thinking "13.1 miles? Not a long way - go for it!" (I PBd by 3.5 minutes). Slightly less extreme, I was once told to "train for a marathon, then race a half-marathon." And seriously, if you regularly run 15 miles or even further, you'll find the HM a lot easier. I think you're being too cautious with "one 15 miler every month" - try working up to a 15-miler every other week, and even, once you're used to those, go a bit further (but remember they're caller long SLOW runs - don't try to do the longer runs too fast, or to increase the mielage too rapidly.

  • Running over distance for most races is a good thing - marathons and ultras excepted.

    As DB above says, do them much slower than race pace, though.

  • Debra thanks - if you've trained for 50k you must know what you're talking about - I'll build up to a 15 miler over next few weeks and see how it goes - will be quite exciting as I've never run further than a HM before!

    I'm guessing that you didn't train over the distance to run your 50k!!

  • Wilkie - thanks - I suppose I'm opening a can of worms here and probably should read another thread but when you say MUCH slower than race pace - what does that mean and why?

    Currently I'm running three 5 mile runs a week and trying one easy (about 8 mins+ whole way, one gradual build up from 8 mins down to about 7 mins, and one flat out to try and improve my speed - last one in 6:52/mile) and also doing one long run c. 10 miles and aiming for about 7:45/mile - is this too fast? If so why? Is it because this might lead to injury or some other reason I'm not aware of?


  • SFF: you're welcome. I think the mental effect of the longer runs (13.1 miles no longer seeming a long way) can have as big an effect as the actual physical training.

    For 50K I didn't go over distance but I ran B2Bs - back-to-back long runs Sat & Sun, working up to 27+10 miles in training. And yes, those second long runs were a killer at first. I also found that with each progressively-longer run, the mile or two miles more than I'd done previously were the hardest part - but the next time, those same miles were much easier. Also, it made training for a marathon easier - I knew I could do the distance, I just needed to work on the speed! Presently training for my first 50-miler and worrying because the furthest I'll go in training is about 28+12, which still leaves a LONG way extra to go on the day.Oh well, it will be an interesting experience!

  • DB - WOW! How long does that take??

    As regards running over the distance it makes perfect sense that mentally as well as physically it will be easier to run a HM if I have run further in training - I think I just needed some reassurance from some people who have done it to confirm I was right.


  • I knocked 20 minutes off my (admitedly slow) half PB in a year - I was training for a marathon at the time and I'm sure the fact that I'd run beyond 13 miles made a massive difference to how I felt. The splits show no sign of tailing off at all. OK, so I didn't have much left to pick up the pace, but I certainly didn't die.

    When they say run slow, they mean SLOW - in my case, the half was at ~10:20 min/miles, and I was doing my long runs at 12:xx. So ~ a minute or so slower would seem a resonable place to be.

  • I knocked off a flat HM at Dorney Lakes earlier this year in 1.41 and did a very hilly South Downs HM (3,000 ft of climb) a few weekends ago in 1.50 - winning my age category (over 50).

    My very limited experience is that a HM is as much a mental challenge as anything. If I reach 6 miles and start thinking "Still not even half way yet" then I know I'm in trouble. For what it's worth I ran a few very slow but very long training runs in the months before each HM. I mean 14 to 15 miles in well over two hours.

    I can't testify to the physcial benefits, although I'm sure there were some, but mentally I found it much easier to keep going. During the races I kept thinking, this will be over far quicker than my last training run. So I would say running over the distance in training does definitely help - although as I said I am far from an expert and this is simply my own experience.

  • The idea of the long slow run is to build up stamina without doing any damage to your muscles, and without completely exhausting yourself.  It also means you recover more quickly for your next training run.

    At least a minute a mile slower than race pace would be my suggestion.  It seems hard to do - you want to run faster - but it does seem to work.

    Do shorter speedwork sessions during the week to work on running faster.

    Have a look at the Smartcoach training plans on this site, that will give you an idea of pace for slow runs and for speed work.


  • Thanks everyone - I've just been trying to link everything you say to Mitochondria but I'm struggling to gt my head round it - my understanding is that to develop maximum endurance ability you actually need to train at near full capacity to maximise your mitochondria which maximises your endurance ability - anyone got a simple science explanation??

  • McFloozeMcFlooze ✭✭✭

    No, that's not right!  To maximise your mitochondria you train slow - keep your heart rate slow, think nice and easy.  This trains your body to use fat for fuel instead of carbs and stimulates your mitochondria.  Also it allows you to do a long run with minimal damage so you can carry on training in the week.  If you had to take 4 or 5 days off following a really hard, long run it would be counter-productive, no? And it's much, much more enjoyable which is a key consideration in itself image.  Go on Bing maps, pick the OS drop down, choose a nice off road route and go off exploring.  Finish with a huge pub lunch and a pint, no nicer way to spend a Sunday IMO.  

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