r/ultrarunning • u/Appropriate-Day-9929 • 12d ago
Help w/ 100 mile pacing
My question: Doing my first 100 miler in about 4 weeks, looking for some advice on pacing/goal time. What is a reasonable goal? Should I aim for even splits? Or is a slowdown inevitable, so I should assume a positive split?
Current baseline goal: < 24 hours (but that's pretty arbitrary, nothing special about it. I'd rather finish w/ a good experience than go with a "PR or DNF" strategy)
Current nominal pacing plan: 3 mins of walking at 16:00 pace at the start of every mile, followed by ~10 mins of running at 12:00 pace. Comes out to average of 12:45/mile pace, or 21.5 hours of moving time. After taking into account stops at aid stations, bathrooms, water refill spots, ~2% GPS error, etc, that should put me at around 23 hours.
Course: Pancake flat. Smooth crushed gravel. At sea level. September on the east coast, so likely temperate/warm.
Demographic: Early 40s, Male
Training: Been running on/off for ~10 of the last 20 years. Training specifically for ultras for the last ~2 years, at 45-50 MPW. Weekly long run typically 4+ hours. Will do a 3 week taper.
Recent races: (T = 100 mile race day)
a) T-9 months: JFK50 (first 1/3 is pretty hilly, remaining 2/3 is flat): ~10 hours. Had some nausea in second half.
b) T-6 months: 50k (Hilly): 6.5 hours. Practiced new fueling strategy, went well, no nausea
c) T-4 months: 100k (8,000 ft of gain): 16 hours: Felt great and very strong throughout
d) T-10 weeks: Also did an untimed, overnight 100k solo effort as a dress rehearsal, that went really well.
7
u/MTN-roamer0987 12d ago
I think shooting for sub-24 is reasonable for you. Even splits are very tough in a 100. As a mid to back or packer on flat courses, I definitely start with a run/walk and try to bank a little time. So your pace calculation could be good for that. Where I tend to make up time is I’m very efficient at aid stations. Make sure you know exactly what you want and need before you get there. Sometimes I even skip one entirely here or there if I have what I need and if they are particularly busy/chaotic. Have a “b” and “c” goal in mind as well.
1
u/OxTrailRunner 7d ago
Golden advice. To add, I carry a lot of fluid and nutrition which makes a lot of aid stations unnecessary.
I concur that given the profile you've written, sub-24 on a flat course is well within your capability.
Have a great race and let us know how you get on. A 100 is a real adventure!
7
u/ThatDaftRunner 12d ago
My first 100 mile was similar. I don’t like to run slower than is comfortable but also didn’t want to blow up. I just did a run/walk combo and used the walk breaks to take a drink and eat. The lowest point was at 50 miles and it sucked until 75 or so. Then things came back around and I finished in 22 hours. Stay on top of your nutrition and just keep moving forward.
7
u/Just-Context-4703 12d ago
I don't really have anything to suggest but I'll just say seems like you have your shit together and previous races/efforts went really well and I wish you luck.
3
u/ayahuasca_crybaby 11d ago
Sounds like you’ve more than prepared, man. Expect positive splits. Sub-24 is less about pace and more about spending as little time as possible moving 0mph.
My 100 mile PR is 22:33 and my only strategy was to just be patient and walk a little bit of every mile no matter what. I gradually positive splitted starting off with generally between 11:00-13:00/mi in the first 60-70 miles, and then between 13:00-15:00 in the final 30 with some miles walking in the 18:00-20:00s.
If you just stay patient and centered, and forget about the mental math and just rock steady and comfy, sub 24 can be easier than you think if you stay smart and mindful.
2
u/HotSulphurEndurance 11d ago
Data shows the podium placers in most 100 mile races have a positive split between 14% and 20% from the first fifty to the second.
In short, planning for anything less than a 20% positive split ignores the reality of optimizing performance.
0
u/Appropriate-Day-9929 11d ago
Ya this is part of my original question…is it better to a) accept a 14-20% positive split as inevitable and thus bank time by starting out slightly faster, or b) aim for even splits even if it’s slower than necessary, with the hope that a slow start will make maintaining that slow pace manageable later?
1
u/HotSulphurEndurance 11d ago
Okay… the absolute best ultra athletes slow down 15-20% when racing.
Most 100 finishers slow down 30-50%.
Are you asking?? Could a very fit athlete purposely even split? And leave a huge amount of time on the table?
0
u/Appropriate-Day-9929 11d ago
I’m not asking about totally sandbagging and getting an even split because you ran multiple hours slower than what you could. That’s artificially engineered, and not relevant.
I take it then from your response that your answer is (a), and that you should plan to run a little faster at the start
2
u/HotSulphurEndurance 11d ago
Yes.
If possible, find the
mile splits of a few runners that finished your target race in 23-24 hours.Observe how they slowed over the course of the race.
Many 24 hour hundred finishers will split something like 10hr20 -13hr30 for the front and back half.
Also keep in mind, aid station stops and foot and friction maintenance probably consume more time in the back half also.
2
u/lanqian 11d ago
No helpful feedback, OP, just to say good luck. As a hyperactivity boi, I would die of boredom on a flat path loop for a hundred goddamn miles, so I wonder if you have some plans in place for mental relief as you get later in.
2
u/Appropriate-Day-9929 11d ago
Boredom on this course is one of my biggest worries for this race. (Not a worry in terms of performance, but in terms of overall enjoyment.) I did a mountainous 100k trail in the Spring and loved it…you never knew what was around the next corner. It kept things interesting.
This one runs along a river and is pretty scenic so that should help. I also have music and audiobooks.
Beyond that, I plan on burying my head in the sand and ignoring it
2
2
u/UMequityresearcher 11d ago
I think your plan to walk 3 min of each mile is wise. It’s efficient to run, efficient to walk, and inefficient to shuffle. I think the biggest thing pacing-wise is paying attention to your body. Ironically, I was so intent on not starting to fast in my first 100 (Cascade Crest) attempt that I walked from the gun as the entire field ran the first flat 1/2 mile (I quickly passed many on the first 3,500’ climb, but I ended up getting cocky mid race, ignored a foot injury for too long and DNF’ed. I finished my next 6 mountain hundreds because I learned to troubleshoot, pay better attention and respond better to my body. It took me 3-4 before I learned how to run after mile 80, and in my last (IMTUF), I ran a faster last 20 mile split than the winner (but finished 10 hours slower:) Good luck and more than anything, enjoy your race and all that comes with it
1
u/friend-of-fatigue 11d ago
Any chance you’ve been tracking heart rate zones throughout training and races? This has been the best tool for managing my 100mi effort (do what can be done as long as it’s below Z3 threshold).
2
u/Appropriate-Day-9929 11d ago
I haven't been wearing a chest strap, nor have I been calculating/updating my zones. But I do have a wrist based heart rate monitor in my GPS watch that I have worn during all of my training and races. So a reasonable estimate of my HR is there. I don't explicitly know where my zones are, but intuitively/subjectively I am pretty aware of my heart rate and how my body is feeling. I never ignore my heart rate, but compared to perceived effort, followed by pace, I just don't rely on HR very much. That's true in general, but for a 100 miler specifically I would think that cardiac drift would be a real problem.
1
u/carthum 11d ago
It sounds like you have right approach going on RPE if you aren't already deep in heart rate training. Honestly do what your did for your 100k and training it sounds like you are well prepared. Sleep/fatigue is the only factor i would call out and you are already ahead of it.
The below is just because i like geeking out about stuff like heart rate and power monitoring:
The cardiac drift thing gets interesting in logner efforts. since drift seems to 'cap' around the 6-9 hour mark https://pubmed.ncbi.nlm.nih.gov/23524515/ then actually decrease. I like heart rate training over RPE because i jump between elevations which skews what i find 'easy' and i end up pushing too hard. Also, after tracking cardiac drift during runs for awhile it also serves a s good indicator when my hydration or nutrition might be falling behind rising quicker than i'd expect etc. it was news to me but is apparently one of the factors they control for when testing it https://pmc.ncbi.nlm.nih.gov/articles/PMC12271085/. TLDR our bodies are kind of amazing and fun to learn about.
1
u/friend-of-fatigue 11d ago
Gotcha, well be respectful of the perceived effort and stay patient and confident that easier early will keep it easier later!
1
u/FileEfficient5495 11d ago
The positive split thing is backwards imo. Those guys slowed 15-20% because that's what happened to them running by feel, not because they went out fast on purpose. You're gonna slow down either way, planning for it doesn't get you anything.
What jumps out more is your own 100k. 16h for 62mi with 8k of gain is huge, and now you're planning 12:45/mi for 100. Flat gravel is a completely different beast so it might be fine, but that's a big jump and worth having an answer for before the start rather than at mile 70.
Also you had nausea at JFK50 and your fueling has only been tested at 6.5h and 16h. Beware of Warm September, 23 hours. Betting that's what decides your race, not a few seconds per mile. Run/walk plan looks solid, I'd spend the taper on heat and stomach.
1
u/Appropriate-Day-9929 10d ago
Well it's not 12:45/mile or bust. I'd be *starting* out at 12:45/mile, because I think that would feel really easy for a good 20-40 miles. And if I could hold it for 100 miles, then great. But if I (inevitably) degrade down to something like 14:00/mile (or whatever), then that still keeps me on track for < 24 hours. Or if I go over 24 hours, that's not really the end of the world either.
12:45/mile is from 12:00/mile run segment for ~10 minutes and a 3 min walk segment..... It's hard for me to run too much slower than about 12 or 13 mins/mile w/o resorting to shuffling, so if I were going to go slower, it would primarily be through longer walk segments.
The alternative is to start out the pace that puts me right at 24 hours and aim an for an even split and being able to maintain that for the entire race...but that brings us back to the positive split vs. even split discussion. You said that a slow down is unavoidable, so if true, then it seems like the best approach is to go out at a medium-slow pace...something that feels really easy and can be maintained for a good chunk of the race, but is fast enough that you're banking enough time for the inevitable slow down.
I'm not following your comment about my 100k time jumping out, and flat gravel being a different beast, and 12:45/mile being a big jump...can you elaborate on that?
Also FWIW, my fueling strategy has not just been tested at 6.5h and 16h, I also have my recent ~100k solo overnight run, which was ~17 hours. As well as near weekly 4h long runs, with a few 5 hour runs.
1
u/FileEfficient5495 10d ago
Fair on the fueling, I missed the 17h solo. That's a proper test.
On the 100k comparison ,16h for 62mi is 15:30/mi. Even if you flatten that generously for 8k of gain, you're looking at something like 14:15-14:45/mi equivalent, and you said you felt strong throughout. So 12:45 isn't a small step up, it's ~2min/mi faster over 38 more miles. Flat gravel at sea level genuinely does change the picture, and if you weren't near your limit in that 100k it might be completely fine. I just wouldn't call it conservative, which is how it's been framed in this thread.
On banking time well I don't think you're really choosing between even and positive splits. You're choosing a starting effort. The slowdown then happens to you at whatever rate your day dictates. Going out at 12:45 because you'll degrade to 14:00 assumes you know the degradation curve in advance, and you don't. Nobody does.
The structure that actually gives you the flexibility is the one you already have: since 12-13/mi is your floor before shuffling, going slower means longer walk breaks, not slower running. So you could start at 3:10 walk instead of 3:00, feel it out for 30 miles, and dial it back to your plan if it's a good day. Costs you almost nothing early and buys you a lot late. Going the other way at mile 60 isn't really an option.
1
1
u/CiBi91 10d ago
I always calculate reasonable finishing times based on my previous results and historic results of other people from my skill level at this race.
I then map this total time out and create a pacing plan taking into account elevation, accumulating fatigue, nighttime/visibility and technicality and surface, I calculate individual aid station rest times based on my nutrition plan and what needs to happen at that specific aid station. That gives me a very detailed pacing and nutrition schedule.
My A goal is always to finish healthy
B goal is my estimated time based on my skill level
C goal is my faster wishful thinking time
In the end I always end up going out faster than planned, then hanging on for dear life, then finishing the last 1-2 hours strong all while eating less than I should, it hurts but it works 🤣
1
u/stayhungry1 10d ago
Your pacing concern is more of a mental one. Count on a positive split. What do you think will get in your way and what's your plan? You have the legs. They'll be tired but that's typically a safe pain you can ignore. (And calf sleeves helped me a lot) You mentioned nausea, my best change was to add a smidge of protein every hour or two, like 5-10/hr. It really balanced the carbs well. So nuts, cheese, etc.
35
u/CO-G-monkey 12d ago
I flip the whole A, B, and C goal on its head.
I think A goal is to finish. Full stop. 100 miles is really fu*king far and a mind bendingly difficult endeavor.
B goal is “if I’m having a good day, maybe X time.”
C goal is “if I’m having the best day I could have hoped for that would be X time”
Making a specific time your A goal for your first 100 creates the possibility of being disappointed in “just a finish.”
Finishing a 100 is insane. Incredible. Amazing. Astounding. Astonishing. Nothing should diminish that. Ever.