Training for the 2024 Javelina Jundred 100M

It’s weird how exactly 6 months ago I sat down to reflect on my training for the Canyons 100k. I really enjoyed writing that down, and I wanted to reflect on the past 6 months training for the Javelina 100M.

If you’re interested in reading how my Canyons 100k went, I actually never cross-posted from Strava to this platform, so please head on over there to read my very drafty race review of Canyons.

Couple of things I want to cover here:

1. The training itself
2. My increased focus on hydration and sodium
3. My obsessio with trying to predict how I’ll do.

But before diving into that, let me cover just a little bit about the Javelina 100M.

About Javelina 100M

A lot has already been written about the Javelina 100M, but I just want to share how I look at the race.

The Javelina Jundred is an trail running event held at the end of October near Scottsdale Arizona. The key events include a 100 mile, a 100k and a 31k trail run. The race is held at McDowell Mountain regional park, about 20-30 minutes outside of Scottsdale, AZ.

The course for the 100M consists of 5 nearly identical loops, the first one being 22.3 miles, the others being 19.45 miles, coming to a total of 100.1 miles for the entire course. The course goes up ever so slightly for the first 9 to 10 miles, depending on how you look at it, and then descends back down to jeadquarters. The total vert for the entire race is approximately 7500ft.

Along the route there will be 4 aid stations:

1. Start/finish also called Jeadquarters. Here, crew is allowed.
2. Coyote Camp after 4 miles.
3. Jackass Junction after a 6.5 mile segment.
4. Rattlesnake Ranch after a 5.2 mile segment. This will take you to Jeadquarters in 6.6 miles during loop 1; and in 3.7 miles in loop 2-5.

I did course recon 3 weeks before the race, and the entire race is runnable, with only a few steep hills. If I were doing the 31k loop, I’d be able to run the entire bit; but knowing I’ll be out there for 24 hours, I plan to run it conservatively from the start.

My training for Javelina 100M

I had a good training block. No injuries, got sick once end of August but not for long, and overall I’m super happy. That said, the block wasn’t textbook ideal. I threw a monkey wrench in it myself when I got into OCC in June via a raffle. OCC is part of the UTMB circuit held in Chamonix France, and required two thing I wasn’t planning for: more international travel and more hills than I was planning on training.

Anyway, the structure of my training block looked like this:

1. June -> end of July: speed training with 2 trail half marathons.
2. 1.5 weeks at the end of July / early August: hiking in Alps. Not a single running mile, but lot of vert and lot of zone 1-2 training.
3. 3 week specialised training block for OCC.
4. 1 week in Chamonix for OCC.
5. 8 targetted weeks for Javelina, with 1 hot training 50k 4 weeks pre-race.

This is what that looks like on a chart:

I also did some heat training during this block. However, this heat training was less structured than it was for Canyons. For one simple reason: we had some hot weather, and I had 90F+ weather during my training 50k. I did a couple of warm bath sessions throughout this block, but mainly I’ve been able to get out and run when it’s hot.

Focus on hydration and sodium

While for Canyons I was pretty focused on nutrition, I didn’t really focus a whole lot on hydration. That changed during this block. I ran a trail half at the end of July, and I really suffered from dehydration afterwards. We were hanging out with friends having a picknick after the race, and I felt myself get worse and worse. I weighed myself when I got home, and while I hadn’t weighed myself in the morning, I estimated I was about a good 4 lbs lighter than I should have been, meaning I had 2 liters too few water on me. Now, the number itself isn’t exact - weight fluctuates a lot and this measurement wasn’t exact - but it showed me that if I can get dehydrated during a mild half marathon temperature wise (I ran pretty hard), I could get severely dehydrated during Javelina 100M.

Hydration gets more complicated as races get longer. I did a decent amount of reading of both coach advice in popular science, as well as reading a couple of research papers. Two things stood out to me:

1. Hyponatremia (getting too little sodium) is mainly caused by hyperhydration, not getting too little sodium - although that also plays a minor role.
2. Scientific literature on sodium supplementation has sometimes seen no correlation with sodium supplementation and performance and doesn’t recommend supplementing to replace 100% of hydration and sodium losses, with some recommendations even go as far as replacing less than 50% of sodium losses.

If you want to dive into some of the research, these are some of the papers I enjoyed reading:

1. Prospective Observational Study of Weight-based Assessment of Sodium Supplements on Ultramarathon Performance (WASSUP)
2. International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing
3. Modelling sodium requirements of athletes across a variety of exercise scenarios - Identifying when to test and target, or season to taste

So, I started focusing more on my hydration and sodium strategy. In the past, I had a pretty fixed routine for longer races:

• 40g tailwind / 600ml water in my soft flasks in the front. Gives me 460 mg sodium.
• 1500ml pure water in camelbag.
• Take a salt tab when needed.

I played around with some things during this training block to improve on my hydration / sodium strategy. OCC helped in this regard as well, given that was a 10 hour run, with pretty high temperatures for OCC and some humidity. During OCC, they served a Naak soup, and my body was just CRAVING that soup whenever I could get it. This showed me I needed to adapt a bit more.

So, going into Javelina, this is going to be my plan. Don’t copy this plan for yourself. I’m a pretty heavy and pretty salty sweater.

• Front flasks:
  • Daytime: 20 gram Skratch / 600ml water. This gives me 400mg sodium, meaning 666mg/liter. The main reason I’m switching to Skratch from Tailwind is that I wanted to get something with less carbs per liquid. I’ll eat solids througout the race, and when I’m drinking a ton, I don’t want to overconsume my carbs.
  • Nighttime: 40 gram Tailwind / 600ml water. This gives me 460mg sodium, meaning 766mg/liter. But I’ll be drinking less of this, so hoping to get about the same carbs per hour.
• Camelbag: 1500ml water with 1000mg sodium tablet in it, to essentially give me 666mg/liter. I’ll drink this every time I eat something.
• Supplement freely with any drinks at aid stations, whether it be plain water, coke, ginger ale etc. There won’t be any sodium in them, but that’s alright. I’m not aiming for perfection, just staying ahead of hydration losses.
• Supplement as needed with a salt capsule, but don’t overdo it.

I’ll see if this updated strategy will carry me to the finish line!

My obsession with predicting my performance

With hydration dialed in, the next big focus was figuring out how my race would play out on paper. And I’ve been obsessed with analysing past results to try and predict my result at Javelina. Not only my finish time - which I hope ends up sub 24 hours, but also my splits per lap.

I’ve spent a decent amount of time analysing previous year split times, and then trying to come up with a good estimate about which laps times put me in shape to finish within 24 hours.

After having spent time on course, I actually feel somewhat good about the prospects of a 24 hour finish. Although I didn’t run an exact lap 1, it looks like it would take me 4:05 to run lap 1; which puts me in line with historical 24 hour finishers. That said, it’s not a guarantee. I could get hit with anything, ranging from twisted ankle, to dehydration, to upset stomach.

Here are a few fun datapoints I pulled from historical times:

First, a boxplot with historical lap times for 20-22 hour and 22-24 hour finishers.

Second, a table showing for the 20-22 and 22-24 hour cohort the 25th, 50th and 75th percentile lap times. As you see, for the 75th 24-hour finish that leads to a over-24-hour finish; which is understable as it takes the slowest 25% lap time amongst the entire cohort.

For the 20-22 hour cohort:

For the 22-24 hour cohort:

Third: showing the lap 1 and 2 times of runners, and the amount of runners who finish sub 24 hour.

Final thing I looked into was UTMB scores. Javelina is a UTMB-index event, and hence each runner gets a UTMB results. Based on my Canyons and OCC UTMB score, I would end up wiht a 25 hour finish time. Let’s see if I can beat the algorithm!

Let me close this out by saying that, despite all my number-crunching, I’m not planning to run with strict lap time goals. They’re more of a mental check-in to gauge how I’m doing, but the main goal is to enjoy the race, not chase the sub-24 finish at all costs.. Because if I were to start pushing it too early on to hit any potential target splits, I might be risking blowing up. I’d rather conserve energy a bit more early on, and maybe end up being one of the runners with a 5-hour lap 1 that still finishes sub 24!

Wrapping up

Training’s done, now it’s taper time and I’m feeling cautiously optimistic. This training cycle has been good and I’m stoked to see what I can do at Javelina. I’ve put the miles in, adjusted my approach to hydration, might have gotten a little obsessed with race splits—but hey, that’s part of the journey. I know that no matter how much prep goes in, race day is unpredictable. My focus is to stay steady, keep moving forward, and, most importantly, enjoy the process. Sub-24 would be great, but finishing healthy and happy is the ultimate goal.