Ultra Marathons

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Velociraptor 16 Oct 10:02am, 16 Oct 2024 71,485 posts	0 Velociraptor With 4.25 for a marathon, the calculator gives me 7.07 for 50k
K5 Gus 16 Oct 10:07am, 16 Oct 2024 6,260 posts	0 K5 Gus Yeah, mine looks a bit off as well : 3:15 Mara -> 5:14 for 50k So 2 hours to do an extra 5 miles..........
Ian5 16 Oct 10:07am, 16 Oct 2024 356 posts	0 Ian5 Fetch-I put in 3:20 and for 50k it gives me 5:22,that's 2 hours for an extra 5mile,is that correct or have I mistyped?
K5 Gus 16 Oct 10:11am, 16 Oct 2024 6,261 posts	0 K5 Gus I think the problem may be that many (most ?) ultras are trail rather than road, so the data that fetch is using could be skewed by courses with quite a lot of rough terrain and altitude gain
fetcheveryone 16 Oct 11:15am, 16 Oct 2024 31,165 posts	0 fetcheveryone I agree @K5 Gus I think that’s likely to be a factor. A few other things I haven’t incorporated: 1) experience. If you’ve done only one marathon and one ultra, your time ratio may not be representative 2) some runners convert better than others. I tried to highlight this when mentioning the 49.5% of runners on either side of the prediction 🙃 but I wonder if I could look at each runner’s HM>M conversion to see how well they retain speed over longer distances. It’s always going to be tricky though for these longer races - as you all know, so many things can have an impact.
flyingfinn 16 Oct 11:46am, 16 Oct 2024 3,741 posts	0 flyingfinn fetcheveryone wrote:I agree @K5 Gus I think that’s likely to be a factor. A few other things I haven’t incorporated: 1) experience. If you’ve done only one marathon and one ultra, your time ratio may not be representative 2) some runners convert better than others. I tried to highlight this when mentioning the 49.5% of runners on either side of the prediction 🙃 but I wonder if I could look at each runner’s HM>M conversion to see how well they retain speed over longer distances. It’s always going to be tricky though for these longer races - as you all know, so many things can have an impact. Another one to consider is the elapsed time between the two pbs. My marathon and 100k pbs were 23 years apart.
Shades 16 Oct 11:49am, 16 Oct 2024 4,445 posts	0 Shades I think most calculators would use roads stats for this type of calculator. Then if for instance your trail marathon was an hour slower then you would use that time to estimate an ultra over the same terrain. Perhaps WAVA would give more realistic results. I ran a marathon, 6 hour and 50 miler within a few weeks, all PB'S. For the 6 hour I ran 5 miles further than the prediction and for the 50 miler I ran 3 hours quicker than the prediction. The 50 miler was over a hilly course too.
cackleberry 16 Oct 12:36pm, 16 Oct 2024 4,132 posts	0 cackleberry I must be the 1% in the middle, just tried the calculator - put in my best marathon time and it has given me a 50mile time just 1/2 hour out and a 100km time not far off reality. The 100mile prediction seems a little slow, but I am yet to complete one to have a proper reference point. Fun!
RooA 16 Oct 12:45pm, 16 Oct 2024 2,908 posts	0 RooA I don't have a marathon time because I have to be awkward. But I put my recent half time... which wasn't a full effort, more a progressive run... into the marathon predictor. That gave me 4.55 for a marathon. Put that in the Ultra calculator and it gave me a pretty good guess of my 50K time, for my best 50K... not the the hilly, rough, windy and rainy one. 😆 I think Ultras are so variable it's very hard to predict. I'd expect to be a fair bit faster for a flat 50K on good ground, in good conditions... but if it's taking data from all 50Ks, it'll be your predicted time for an averagely hard/hilly/technical/weather-afflicted 50K.
Gromit 16 Oct 12:46pm, 16 Oct 2024 2,006 posts	0 Gromit I'm the same @cackleberry the times are pretty spot on for me too