1:52 2:08 split for 4hr Marathon

Does anyone have any advice/thoughts on the idea of doing a 1hr 52 min then 2hr 8 min split for a marathon to try and get 4hrs? I read about this somewhere, its saying that most 4hr runners will be under prepared for the full marathon and will therefore definitely slow, so cant aim for a close split, need to have time in the bank for the inevitable losses in the last 6 miles or so. Presumably a 1:52 half will have to be pretty comfortable and not near to PB pace.  

 

Thanks

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Comments

  • literatinliteratin ✭✭✭

    That sounds like a massive split to me, and more likely that under-prepared runners would destroy themselves running the first half too fast, and then struggle in the second half as a result.

    It also seems odd to base your race strategy on planning to be under-prepared. Unless the race is in the next two weeks and you've run out of time to train. It may well be true that 'most 4h runners will be under-prepared', but there's no need to be one of them.

  • MillsyMillsy ✭✭✭
    Lit has said pretty much what I was going to say.



    If a 1.52 pace for the first half is pretty comfortable then you should be able to replicate that in the second half. If you are underprepared, now is the time to focus on not being that person.
  • Wouldn't it be fair to say that all but the most experienced/talented marathon runners will fade in the last 6 miles or so, therefore you are pretty much guaranteed to fail if you set out at 9min miles. How many runs in training between 13 and 22 miles would you consider sufficient to be properly prepared?

  • MillsyMillsy ✭✭✭
    Talent will have very little bearing on it. It will be down to sufficient preparation and also picking a sensible target to aim for (based on previous results and amount of training done) and actually sticking to that pace.

    I can see the advantage of planning to have 60-90 seconds in the bank at halfway just in case of any minor issues (shoe lace / toilet stop etc) but any more seems unnecessary unless the course is significantly hillier in the second half.



    Is this your first marathon? If I remember correctly I did 3 X 20 milers and about another 5 runs of over 13 miles.



    Are you following a plan? Have you done any other races?
  • literatinliteratin ✭✭✭
    scottles wrote (see)

    Wouldn't it be fair to say that all but the most experienced/talented marathon runners will fade in the last 6 miles or so, therefore you are pretty much guaranteed to fail if you set out at 9min miles. How many runs in training between 13 and 22 miles would you consider sufficient to be properly prepared?

    Not really. My friend who has only run one marathon (in about 3:58) had a half marathon PB of (I think) just under 1:50 when she did it. It would have been suicidal for her to aim for a first half that close to PB pace; she faded a little bit in the second half, but not drastically. I don't know how many long runs she had done or what mileage, but I know that although she had trained consistently, it was not as much as I would do (I have run three marathons either side of 3 hours). You're only 'guaranteed to fail' setting out at 9 minute mile pace if you aren't fit enough to run a marathon at that pace.

  • Thats your legs falling off that is.... Over a minute a mile slower.



    Whats your HM PB ? If you double that and add 20 then thats about the time for the full.



    I'd assume a bit of slowing down in the last half - but not 16 mins.

    (damn just checked last year and I slowed about 7 mins on the last half - but I know I was underprepared on the long runs.



    Year before was better 3 mins slower - but due to pacing the first half better.



    If you go too fast in that first half - you will pay BIG time over the second half.
  • I am doing London for the second time. last time I did 4:35 but was very underprepared due to a fractured rib a month before. I had done two runs of 15 miles. At the time, with this training, I was able to run a half in 1:46, so knowing how underprepared I was, I set out very conservatively (I thought) and went through halfway at 2:07 and felt like I had hardly broken a sweat. I still did suffer at 20 miles onwards but managed to plod home at 10.5 min miles after a mile of walking (to avoid cramping) to get 4:35.  This time I am hoping not to crack a rib and prepare better! However, I still think realistically I wont be ideally prepared for the distance as I wont be able to do enough long runs to prevent some significant slowing In the last few miles, so just trying to think of the best strategy and read about the 1:52/2:08 split.

  • MillsyMillsy ✭✭✭
    What makes you think that you are not prepared for this years race?
  • If you're in 1.46 shape still, then I think going out in 1.52 will cost you. Its just a bit too fast I fear. Maybe do the 1.56 and then you have an extra 8 mins over the second half for slowing to get under your goal ?
  • Cos I have only run 13 in training so far. have another 13 this weekend then a half race next weekend then hopefully a 15 17 and 20 to fit in and that's it! I doubt that is enough to qualify as ideal.  

  • I guess its a careful balance between time in the bank and overcooking the first half.

  • I was one of those people.

    I dropped about 15 minutes in the second half of my first marathon due to being undertrained / overambitious. This comprised rattling along happily at target pace until about 17 -18 miles then gradually slowing to an interminable plod for the last few miles.

    I considered this to be a bit of a disaster and certainly not something I would deliberately plan for.  A two or three minute buffer is probably reasonable provided your goal time is realistic.

     

  • I'd think about not using the half as a race but focus on using it as race prep.



    You're not ideally trained up for the half - so racing it will take it out of your legs.



    Why not use it to go at your marathon pace and maybe even sneak a bit longer onto it afterwards ?



    If you've done 1x 13 then you could do :



    15

    13

    17

    20

    15

    20

    easier week

    Race ?



    (i think thats the right number of weekends ?image
  • "Time in the bank" is a fools errand.  If you're not fit enough for sub four then you're not fit enough for sub four.  Overcooking the first half will only make that worse.

  • You think If I can manage what you suggest (or similar) then I should be trained enough to aim for a reasonably close split? Maybe 1:55 2:05?? Is a 20 miler 2 weeks before a bit close??

  • It seems that a half PB is not a great marker to determine if one is fit enough for sub four (if its sort of borderline). Maybe a 20 mile race would be a better indicator??

  • MillsyMillsy ✭✭✭
    If you are underprepared, racing a 20 miler will only burn you out before race day.

    If you haven't even done 20 at training pace then attempting to race that distance seems far too much.



    What plan are you following? It seems a bit light on the long run mileage
  • Oh christ no - do not race a 20 miler ! As Miullsy says - that will be your race day there. You'd not recover properly.



    You ARE slowing down the long runs yeah ?
  • Interesting read. Banking minutes is not a good marathon strategy. As said going to fast in the first half will catch up with you in the second half. 

    Last April I did Manchester off the back of a 1.32.58 HM PB 5 weeks before but planned the first half of the marathon at 1.50 and went through the half way at 1.50.17 and the 2nd half of the race in 1.48.28 to smash my marathon  PB. Previously I thought I would 'bank' the minutes. 

    In answer to to your how many long runs between 13 and 22 miles, well I work to the theory of your 5 longest runs total 100 miles. So so far in my training I have totalled 94 miles, runss of 17,17,18,20,22. 

  • I think it's more productive to consider overall mileage during that peak 6 to 8 week period rather than focusing just on long runs - provided you're following a balanced marathon specific plan.

    And so, having thought about this for about 5 minutes, I shall unveil my universal marathon predictor.

    weekly mileage of 50-60 or more miles per week - 2 x Half Marathon Time (HMT) + 10 mins

    40-50 miles per week - 2 x HMT + 20 mins

    30-40 miles per week  - 2 x HMT+ 30mins

    less than 30 miles per week imageimageimage

    This is based on a statistical sample population of 1, so may have a high margin or error.

  • MillsyMillsy ✭✭✭
    Lou, that predictor works for me. Last time I ran a decent half in the build up to a marathon was 2013. 1.24.45 converted to 2.58.15 off about 55mpw.
  • And for my last marathon I fitted into the last category for sure. Peak mileage 26mpw.

    Result: 2* Half marathon pb +55 mins image

    I am scraping into the 30-40mpw this time, but it still seems unlikely I can manage a sub 4 with a 1:48 pb, cos that would be 2XHM+23 mins.

  • Aah that's well off for me luckily
  • That's quite interesting. But aren't they saying that this is how most people have gone sub 4 ?



    That might not have been their plan at all. Looks to me like they have gone out too fast and faded too much in the last half.



    If you could test with two people of the same fitness I'd wager that sending one of them off too fast would result in a much slower time than someone pacing it a bit more evenly.





    Impossible to test sadly.
  • Maybe even paced to 20 miles in 2:58 is the compromise, this would be 1:56 at halfway. This would allow a fade to just under 10 min miles for the last 6.2 which should be achievable if you are anywhere near fit enough for the sub 4.

  • SlowkoalaSlowkoala ✭✭✭
    I was advised in my first marathon to bank effort not time. I'm struggling to paste this as a link but the main bit is (no bonking jokes please).



    'If you???ve trained for a marathon, you???ve probably encountered the term ??? putting time in the bank???, which refers to running the first half of the marathon slightly faster than goal pace to compensate for being slow the last 10km of the race. Unfortunately, this racing strategy couldn???t be more wrong, both from a physiological standpoint and from empirical evidence.



    The main problem with the ???time in the bank??? strategy concerns the use of carbohydrates or fats as a primary fuel source. One of the limiting factors in marathon performance is how efficiently you can burn fat instead of carbohydrates for energy. Once you burn through your available carbohydrate stores, your performance will suffer, most notably from ???bonking??? or running out of fuel. Unfortunately, the faster you run, the more carbohydrates you burn (study here). Therefore, by starting faster than goal pace and putting ???time in the bank??? you???re actually burning through your available carbohydrate stores faster and you will almost certainly run out of fuel and bonk.



    If you???ve trained for a marathon, you???ve probably encountered the term ??? putting time in the bank???, which refers to running the first half of the marathon slightly faster than goal pace to compensate for being slow the last 10km of the race. Unfortunately, this racing strategy couldn???t be more wrong, both from a physiological standpoint and from empirical evidence.



    The main problem with the ???time in the bank??? strategy concerns the use of carbohydrates or fats as a primary fuel source. One of the limiting factors in marathon performance is how efficiently you can burn fat instead of carbohydrates for energy. Once you burn through your available carbohydrate stores, your performance will suffer, most notably from ???bonking??? or running out of fuel. Unfortunately, the faster you run, the more carbohydrates you burn (study here). Therefore, by starting faster than goal pace and putting ???time in the bank??? you???re actually burning through your available carbohydrate stores faster and you will almost certainly run out of fuel and bonk.



    To prevent bonking, you must adhere strictly to your goal marathon pace. Why? Your goal marathon pace corresponds to your aerobic threshold. Your aerobic threshold is the point at which you start relying on anaerobic respiration . Anaerobic respiration requires higher amounts of glycogen than aerobic running (study here), so you burn carbohydrates more quickly when you rely on anaerobic respiration.



    Therefore, making the mistake of running 10-15 seconds faster than your goal marathon pace, even for just a few miles, can cause you to bonk or be detrimental to finishing as fast as you possible can'.



    http://runnersconnect.net/running-training-articles/improve-your-pacing-skills/
  • literatinliteratin ✭✭✭

    I agree with Cougie. There's no point basing your race strategy on statistical analysis when you're already working on the premise that most marginal sub-4 runners are undertrained and pace badly. I also agree with Lou that total regular weekly mileage is probably more important than the number and length of long runs.

  • I just remembered a marathon pacing platitude wot I heard somewhere of other - for each minute you gain in the first half, you will lose two minutes in the second half.
  • On a flat out- and back course, my 3 closest to 4 hr finish times were:

    3:55 = 113/122

    3:59 = 115/124

    4:09 = 120/129

    So- no matter what my finishing time was, my second half was always 9 minutes slower thatn the first.................never noticed that before!

    I would have said that for all of these , I was under- prepared in terms of long runs, my mileage has only rarely been over 30 miles per week. I would hope that you don't need to slow down much more than that- it was a significant slowing!

    My half marathon - to marathon conversion has been about 2xHM + 25 mins.

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