A calculator for predicting marathon time based on elevation profile

Chuck pointed me to Greg Maclin's site and it's excel calculator for predicting marathon times as a function of hills and turns. I've now wasted 1.5 days building my own calculator in R based on hills only. R is a statistical programming language and I cannot compile it to make a web applet. Sorry.

Background info: Basically, every 0.05 miles, I compute a "pace adjuster coefficient" based on the grade of the terrain for that 0.05 mile segment. The pace adjuster coefficient is just the % increase or decrease in the expected pace on a flat course due to a hill. The formula for adjustment are from Maclin's xls predictor. Hills affect us more late in the race so the pace adjustment percentage increases for climbs but decreases for descents after mile 16 and even more after mile 21. The difficulty of a marathon (based on hills, at least) can be summarized with a single factor, which I'll call the Marathon Difficulty Factor, which is just the average pace adjuster coefficient over all segments.

The problem with any such calculator is the estimation of the elevation profile. Here are the total ascents (in feet) of 5 marathons using 4 different websites:

Marathon		Maclin	MMR	ARR	RA
Boston		544	295	897	1129
Maine		NA	427	955	1230
Manchester		629	758	NA	1742
Baystate		526	295	552	583
MDI		NA	659	1870	2252

MMR is mapmyrun, AAR is USATF's America's Running Routes, and RA is RunningAhead.

In general, the total ascent is ordered RA > USATF > Maclin > MMR but there are enough exceptions that no general rule can be created. More importantly, these differences have consequences on the calculated running time (and Marathon Difficulty Factor). Because I can manipulate the smoothing parameter of the spline that I fit to the elevation profile, my calculator can compute the expected time based on any of the above estimates. Cool huh?

So here is what I get for the Maine Marathon based on a 3:00:00 marathon on a flat course (MDF is the Marathon Difficulty Factor, which is the same for any goal time. Multiply the MDF to your flat-course pace and you've got your hilly-course pace!):

Ascent Time MDF

RA 1219 3:02:47 1.0154

ARR 955 3:02:10 1.0120

MMR 425 3:00:53 1.0050

So which am I to believe? At the bottom of this post, I've inserted an image of the three elevation profiles for the Maine Marathon based on the above three total ascents. Based on my knowledge of the course, the MMR profile is clearly too smoothed; it underestimates both the grade and peak elevation of the hills (that is, it flattens the hills out over a longer distance). The RA estimate looks to be not smoothed enough. And the USATF estimation looks about right.

Added at 6:16PM: MapMyRun ignores ascents less than 60 meters. Holy cow! Even the downloadable .csv files though seem to be oversmoothed relative to the other sites.

For my running bro' Jamie, here are the estimates for the MDI marathon

	Ascent	Time	MDF
RA	2112	3:04:57	1.0275
ARR	1857	3:04:20	1.0241
MMR	660	3:01:34	1.0087

Two notes:

1. I always wondered how much hills mattered. Is MDI 1 minute or 5 minutes or 10 minutes slower than Maine for a 3Hr Maine marathoner? Based on my initial results, I'm pleasantly surprised to find that something like MDI probably adds only 2 minutes on top of Maine. However, just like Mt. Washington, when things go wrong on hills, they can go very wrong. That is, if a hill is run too fast (the actual pace isn't adjusted by effort), a slow death spiral will surely result. So a well-run hilly marathon should be within 2-5 minutes of a well-run flat marathon but a poorly-run hilly marathon will be many, many minutes slower than a well-run flat marathon.

2. For the purpose of comparing MDF among marathons, what we really need is course elevation profiles collected and smoothed in the same way. Maybe all MMR or RA or USATF.

The RunningAhead elevation profile of the Maine Marathon. A little undersmoothed?

The USATF America's Running Routes profile of the Maine Marathon. About right?

The MapMyRun elevation profile of the Maine Marathon. Definitely over smoothed.

Fall (post-marathon) goals

1. win Wolfe's Neck 5K

2. win Pathfinder's 5K

3. sub37 at Great Osprey 10K

4. run in hell

1. row on erg

2. double pole on roller skis

3. look for snow

So true, Robbie

The best laid schemes of mice and men
Go often askew,
And leave us nothing but grief and pain,
For promised joy!

Physical Therapy

First, let me congratulate my running buddy Jamie Anderson for the BQ at the badass MDI marathon. Wooooohooooooooo! Sweet, we're going to Boston! I was very anxious last night and this morning and very glad that mad spectator Ryan was tweeting updates. I got the news at about the Freeport exits of I-295 (don't tell the state troopers!).

Training has gone well this season and I'm in the mood to race so I hope to jump in 3-5 races over the next few weeks, both XC and road. Unfortunately I trained for the marathon and have done no running faster than MP - 10s for about 8 weeks and prior to that my speedwork was only at 5K pace so this isn't the best prep for fast xc and road races. I also of course ran a marathon two weeks ago which itself is not good prep for fast xc and road races. So my Craig Cup last saturday was my first speedwork of the fall. I was hoping to do more speedwork Wednesday but my calves are shot from the perfect storm of marathon/craig cup/low heel shoes so I ran easy at Back Cove instead.

Physical Therapy 8K race report:

Today was my second speed workout and it was again a race - the Physical Therapy 8K in Brunswick. I had not run this race before but Floyd L., David R., and some other FODs have run this over the past few years so I was hoping to see them. The race is also free for MTC members so that sealed the decision. I punched 17:45 5K into MacMillan's calculator (which is 13 s faster than my PR but I feel good!) and got a goal time of 29:15 or 5:53/mile. I didn't see Floyd or David or any Dirigo masters but I did see Bob Ashby, who has some impressive marathon times. I also had a nice starting line chat with Mike Bunker who took my A&P class a few years ago and is a wicked fast former USM steepler. I took off at what I was hoping was 5:55ish and pretty quickly found myself alone in 5th place with a decent gap both in front and behind. It largely stayed this way for the rest of the race. I hit mile one in 5:56 and felt good. I hit mile two in 5:53, again good. I hit mile 3 in 5:56, again good but about 3s slower than I wanted. Very soon into mile four I caught and passed the fourth place runner. We had turned into a wind and I was hoping to share the pulling but he was hurting. Mile four is a slight hill - about 80 feet in 1/2 mile and it was against a slight wind. Both seemed pretty trivial but my mile 4 split was 6:07. Ouch, I was hurting throughout mile 4. Mile 5 was just brutal. I was slowly catching up to the 3rd place which was a woman that I didn't recognize. But I couldn't catch her. I was spent. Last .9x mile was at 5:59 pace. Finish time 29:42, 4th overall, 3rd male. Mike Bunker cruised in for an easy win and Bob Ashby cruised in for an easy 2nd place. The woman turned out to be a former Brown U. runner Jenna Krajewski. I was a teeny bit disappointed with my time. Its about 2-4s slower than my equivalent MD5K/B2B times but I was hoping to have gained speed since then. It was also much harder than my B2B - I was really hurting today but the B2B seemed so easy.

Physical Therapy:

I won a $50 gc to Soakology Foot Sanctuary and Tea House. Which is good because I need some physical therapy. I have both calf and lower back soreness and could use a good massage (not sure about the seaweed treatment though). My lower back mm. have been sore for about a month and last Friday was notable for being the first time that I've not run because of pain. After finishing up a meeting at USM, I was putting my backpack into the car and got a shooting pain in the lower back that felt very much like how my back felt when I played golf in high school. Yes golf really torques the back. Its not a continuous pain at all but a rapid, shooting pain that occurs when the back twists and bends just so (it's very hard to replicate consciously but not accidently). It happened again while driving over to Back Cove. At Back cove I took 2 steps and realized that each pounding foot fall hurt. So while I've taken rest days (and weeks and months) for fear of aggravating an injury, I've never actually not run because it was too painful until Friday. I tested it out with a little running in place yesterday and it felt fine but skipped the TMR SMR nonetheless. Today it was no problem. Hopefully a little soakology will put it to rest.

Craig Cup race report

Wow. Another stunning day to race. We've had a very hot summer/fall but have been extremely lucky on our race days. Twin Brook doesn't get any better than this.

Given my marathon Sunday, I was unsure if I'd race. I took Monday-Thursday off and ran an easy 5 miles Friday. Marathon recovery went well. By Wednesday I had no soreness although I had calf soreness during my friday run. I had decided to race The Craig Cup by Thursday and Friday's run confirmed the decision.

My PR on the course is 19:36ish. I thought I was in sub19 shape but given my marathon training (with no speedwork) and marathon, my goal was a PR 19:30. For those that have not run this course, Twin Brook is about 1:00 - 1:30 slower than a fast road 5K. Many people run it closer to 2 minutes slower. The first mile is a race killer. The last mile is a pace killer. I thought I would run a 6:20 first mile, then 6:15, then see if I could just hang on.

Bam! 6:19 first mile. I didn't even use my watch! I thought by the end of this mile that I had zero chance of running 19:30. But then, Bam! 6:14 2nd mile, again no watch (ok I peeked at the half-way mark, which only I knew). Now I had all those thoughts of ok I'm cooked. I cannot hang on to this pace. But there's only 1 mile left... If I can just...Bam! 6:04 3rd mile. OK hang on, it's a slight downhill 0.1 mile and Bam! 18:58. Sweet!

Props to Matt Lunt for taking home The Cup! Thanks to Blaine for the beautiful pictures and to Jamie, Ryan, Val, Rick, Kate, Dave Howard, and Cacky for all of the race day help (although there was a lot less than I'd thought I needed thanks to USATF Maine).

Maine Marathon race report

There. I've done it. It took me only 5 years of training!

The race was almost perfectly executed. I placed myself upfront but started easy. I used 1/2 marathoners on the way out by running in their wake. They kept slowing down so I'd have to pick up the pace for 30-50 yards to quickly get to the next group. But then after the 1/2 turnaround it was just me. From the 1/2M turnaround (6.5 miles?) to the finish I passed 5-6 runners; none passed me. And I didn't have the opportunity to run with anyone - no one was going my pace.

It was nice to see friends out on the course including James, Brett Hellstedt and Matt Lunt. And Mike Pratico was actually in his car waiting for me to cross Rt. 1 with its intersection with Rt. 88! It was great to have Ryan and Ian in multiple spots. And it was fun to have Cacky and Sam cheer me on at mile 4 when I was feeling invincible. And Tom and Will were working the finish line water handout with FHS XC so I had my whole family at the finish. Falmouth crowds were awesome. Cumberland and Yarmouth was a little sparse. The course is great. Challenging. Not Chicago but not MDI (not that I've run either).

My drink/feeds went surprisingly well considering I have little experience with either. I gu'd at miles 6, 12, and 18. I gatoraded at miles 3, 9, and 15 and I took water everywhere else except the last station. There were definitely plenty of stations for this schedule. The last gatorade didn't sit very well (I really never run on gatorade) but the feeling left after about 1 mile. I also got a bit of that last gatorade in my eye, which stung.

I started to feel the legs as early as mile 8. I made the turn in what I thought was 1:29:05 (a little fast) but the results say it was 1:29:33. By mile 16 I was anxiously awaiting miles 18-20, waiting for the wall. Never happened. Ian ran with me for a short stretch at mile 19 and I felt strong and confident in a 2:58-2:59. I still felt quite strong at 20. At 2o.5 Ryan cheered me on. I thought I was good at this point; Ryan thought otherwise. My split agreed with Ryan. I noticed the high split at mile 21 (6:56) and tried to return back to my goal pace (6:50). Miles 22 and 23 were fine but mile 24 was a disaster. I didn't feel it and was shocked when the watch returned the split. Over the last 2 miles I had really heavy legs and simply couldn't turn them over. I kept trying to increase the pace and I just as quickly fell back. With 1.5 miles left, I knew I wouldn't go sub3. With 1 to go, Ryan tried to convince me otherwise. I thought all it would take is something just under 6:30 but I just couldn't do it. In fact I didn't increase my pace at all.

The end of a marathon is really weird. I wasn't especially tired or exhausted at all, but my body was broken.

My watch finished with 26.44 miles so in the splits below, I include what my watch displayed, the corrected split, and the corrected cumulative split. I did recognize that my watch splits were a little fast (I thought they were 2s fast but, alas, they were 3s fast, and that mattered).

Mile	Watch Pace	Corrected Pace	Cum average pace
1	06:50	06:54	06:54
2	06:48	06:51	06:52
3	06:43	06:47	06:51
4	06:43	06:47	06:50
5	06:47	06:50	06:50
6	06:47	06:50	06:50
7	06:51	06:54	06:50
8	06:51	06:54	06:51
9	06:50	06:53	06:51
10	06:50	06:54	06:51
11	06:45	06:48	06:51
12	06:44	06:47	06:51
13	06:48	06:51	06:51
14	06:46	06:50	06:51
15	06:47	06:50	06:51
16	06:43	06:47	06:50
17	07:00	07:04	06:51
18	06:49	06:52	06:51
19	06:48	06:52	06:51
20	06:48	06:51	06:51
21	06:56	07:00	06:52
22	06:46	06:49	06:52
23	06:50	06:53	06:52
24	07:05	07:09	06:52
25	06:58	07:02	06:53
26	06:59	07:02	06:53
26.22	06:58	07:02	06:53

Final time: 3:00:36

If only I had run a 20 miler...

I'd have broken 3 : )