Marathon negative split

4 watchers

dd2411 Oct 2012 3:43pm, 22 Oct 2012 10 posts	0 dd2411 hi, I ran abingdon yesterday in 4.11.42, a massive 28 min pb from my previous marathon (london in april). I planned to start slow, run steady and then speed up if I had anything left at the end. I ended up with a 5 min neg split as i gradually sped up through the distance, expecting to hit the heavy legs and fade at some point, which never happened! I have done a fair few long runs with this sort of technique of basically a start slow progressive run, 5m splits - 49.41, 48.45, 47.51,47.05,46.14, 12.08 for the last bit, does this just mean i went way too slow at the start ( probably being a bit over cautious of going off too fast)? wondering how close i can get to sub 4 in the next one after another 6 months training!
Grid Oct 2012 4:00pm, 22 Oct 2012 1,795 posts	0 Grid If you hold back a bit at the start, you'll burn carbohydrates more slowly than you would otherwise have done. This makes your carbohydrate fuel tank last that bit longer, reducing the amount of time/distance that you have to rely on burning fat. If you overcook things at the start, you'll deplete your reserves too quickly and start burning fat earlier. On the basis of the above I would recommend people plan to run a negative split when they're running a marathon. Note I've completed only one marathon (in just under 5 hours) and died on my arse in the other one that I attempted, so perhaps I'm not quite the authority you might be looking for on the matter. If you're interested you might like to look here for an example: feelrace.com
Grid Oct 2012 4:06pm, 22 Oct 2012 1,796 posts	0 Grid Congratulations on the PB by the way.
TRO Saracen Oct 2012 4:20pm, 22 Oct 2012 6,867 posts	0 TRO Saracen GRid is correct re analysis, and chances are that was a well paced run and fitting of your current fitness levels. Congratulations btw - on the PB but more importantly on a well paced and executed marathon. There's many who take a long time to be able to do that, it takes patience which you don't feel like at the time. Going so easy early FEELS wrong as it's so easy it's almost not like racing at all but you get it all back, and more with the extra pace at the end. And doesn;t it feel great overtaking and moving through the field and finishing strong. If I was you I'd be after a sub 3:50 next time out. Give yourself some time off, then do some speedwork (park runs? 10k's) and maybe cross country, and you should start next training prog from a substantially higher base than the previous. Adjust your times/paces accordingly. FWIW I had a beautiful negative split marathon on Sunday as well (Great Yarmouth). 20 metronomic miles at 7:15 pace, then a final 6 at 7:00 pace for a 3:09. I;m a big fan of this sort of training/racing as I tried the other way many times without the same success. Previously I'd always try to build a buffer in the first half, so that I had time banked for the inevitable fade. Never really worked out like that.... Good luck!
dd2411 Oct 2012 6:00pm, 22 Oct 2012 11 posts	0 dd2411 thanks TRO and Saracen! i dont know whether it was the effect of carb loading but i actually felt pretty sluggish for the first 8 miles and wasnt exactly holding back to run that slow... it woud've been a big effort to run much faster, then i settled into a bit of a rythym from then on. well done on the PB TRO! thats my plan, do some parkruns / 5m/ 10k and get those down a bit before upping the mileage a bit on the next marathon schedule ( i did hal higdon intermediate 1 time round, maybe intermediate 2 next time) what pace are your long runs compared to your MP? i was worried mine were a bit too fast, starting between 9.45-10 then speeding up to what ended up being my average MP at 9.30 ish, do you think i would benefit from slowing these down more?
paul a Oct 2012 6:04pm, 22 Oct 2012 9,699 posts	0 paul a The chances are you have trained more since VLM and this was the real reason for the big PB - well done. So almost certainly you went too slowly at the start......but it produced the goods. There should be more to come.
Phil70 Oct 2012 6:13pm, 23 Oct 2012 25 posts	0 Phil70 Well done dd2411 - you must be on a high! Having got behind with my marathon training, I just took on a 10k at the weekend and took six minutes off my PB, then again I went off quick and finished even quicker. However, I'm due to run quite a few marathons between April and May next year and I've got to learn to run negative splits otherwise I'm sure to have a DNF next to my name somewhere. Despite intending to run off slowly at the start, I seem to lack the discipline to hold it together and slow up badly after 18 miles.
Da Big Guy Oct 2012 6:24pm, 23 Oct 2012 450 posts	0 Da Big Guy My opinion is this:- On a particular day there is a particular time you are capable of ie the best you can possibly do. Anything less means you did something wrong, most probably on pace. I believe the perfect race is dead even pace with a slight pick-up in the last 2-3 miles. This will obviosuly give you a negative split. So yes, negative split is ideal but you can only plan to do thisif you know what you are capable of. In my opinion the optimum negative split might be a minute at most. 5 mins seems a lot ie you ran maybe 10s/mile too fast in the first 20 miles. Interestingly (and I wrote an unpublished Fetch newsletter on it) the lead runners in big marathins very rarely run negative splits. Just have a look. It says to me that many of them get caught up in the pack and go too fast. I know a pack has benefits but running too fast is a sure fire way to slow down in the last few miles. Well done on run.
fastfreddiescat Oct 2012 6:24pm, 23 Oct 2012 186 posts	0 fastfreddiescat This is a really interesting thread. In Berlin 4 weeks ago I too ran a neg split @ 1:38 half & thinking if I could up the pace I'd come home in around 3:15. I ended up coming home in a 15min PB of 3:13:26, & interestingly each 5k split was quicker all the way through, with the last 10k in 44 mins. I will try a neg split on the next attempt but push on a bit.
JohnnyO Oct 2012 7:23pm, 23 Oct 2012 13,972 posts	0 JohnnyO Even pace. Pick a speed and run it. I find trying to go slow and then speed up doesn't work for me, but everyone is different.