McMillan's Running Calculator (Read 2818 times)

Am I crazy. Some of these predictors say I will cross the finish line in my first marathon @ 3:30-3:40. This seems too fast for me. I ran 3 half marathons last year at a PR of 1:42:02. Doubling that distance, I don't think I could possibly run that pace for the whole salami. My goal is to do this thing at 9:00 per mile pace (around 3:55:00). I have been running about 1 year and a few of months. Any imput would be appreciated. I am beat after my long 18 or 20 milers at 9:00 pace. Worried......

Am I crazy. Some of these predictors say I will cross the finish line in my first marathon @ 3:30-3:40. This seems too fast for me. I ran 3 half marathons last year at a PR of 1:42:02. Doubling that distance, I don't think I could possibly run that pace for the whole salami. My goal is to do this thing at 9:00 per mile pace (around 3:55:00). I have been running about 1 year and a few of months. Any imput would be appreciated. I am beat after my long 18 or 20 milers at 9:00 pace. Worried......

Here's a very good answer just a few posts up from yours:

The McMillan calculator, like all running calculators, has to be taken with a grain of salt. The further your starting distance is from the predicted performance, the more uncertainty i.e. if the 1:40 half is predicted from a recent 10 mile race, it's more believable than if predicted from a 5k. The big caveat that's usually not made clear is that the predicted times are times you could run if you embark on specific training for those distances. Working your number backwards: let's say you've been training for a 5k, doing 5k-specific workouts, and you crank out a PR of 21:38. McMillan says that's equivalent to a 1:40 half. But does that mean you could go out the next weekend and do it? No -- it means that from where you are now with the 21:38, if you embarked on say an 8-12 plan of half-marathon specific training, the 1:40 would be attainable.

I agree completely. All of these calculators assume that: 1) you are fully trained for the distance, 2) conditions approach optimal conditions, and 3) for the longer distance, you've got the endurance to maintain the pace. The big problem, I think, starts after half marathon distance. ESPECIALLY if you've never run a marathon. There are too many factors that go into miles after 13 (and especially 20-26), that may dramatically impact your time. McMillan tells me I can run between a 3:37 (from my 5-k time) to a 3:42 (my HM time). Interestingly, all of the numbers from 5-k to 13.1 are awfully close. But I have yet to run a sub-4:00 marathon. My PR is 4:11, a full half hour off McMillan's prediction. I think I will in a month, but it won't be a 3:37, that's for sure. Not even with perfect conditions. (Which for me means cold or colder or coldest). This advice has been repeated a few hundred times, so here's one more time: for your first marathon, you might consider just not worrying about time, running hard but comfortably, and seeing what happens. You'll definitely enjoy yourself more. If I had to guess, I'd bet you'll run just under 4:00. Depending on the conditions. If it's hot or windy or a hilly course or the gatorade is mixed wrong or you just have a bad day, who knows? All I know for sure is my worst marathon came from forcing my pace to stick to what I thought it SHOULD be, rather than what I was really trained for. That time I barely finished, and barely broke FIVE hours. Shorter version: go run the marathon, then look at McMillan, and see what you think. Maybe you'll BQ. Maybe you'll run 4:30. Neither would surprise me.

JN is wrong. JN will run 3:37. JN better run 3:37. Or pray the weather is hot. Oh yeah, JN, one month.

I take it back. There is one very accurate calculator. I call it my Trent-O-Meter. Just check Trent's time. Subtract 2 minutes. There's my time. Works like a charm.