How to Run 100 Miles: The Art and Science of Endurance-Week 14

Physiology First
9 min readFeb 3, 2022

What does “endurance” mean to you? To write a training program that is universal to all runners aiming to accomplish a 100 mile ultramarathon is to ignore this fundamental question. We could ask everyone to run 100 miles per week and hope that more people survive this mileage than are injured by it. We could add mileage for no specific reason without asking the critical question-what adaptation are you trying to achieve?

What happens in the body when we run at a slow pace for hours on end? Is it aerobic capacity that we are improving? Is it tendon and joint health that we are working to strengthen? Is it pure muscular endurance that we are hoping to improve?

I’ve run over a dozen ultramarathon races with vastly different mileage plans and I have a cool pile of belt buckles that I’m really proud of.

I’ve run 100 mile+ weeks and had crappy races. (I’ve also experienced the beat down on the physiology of the body which goes far beyond sore muscles and into decreased heart rate variability, depleted testosterone levels, erratic sleep patterns, and a largely catabolic (breaking down of muscle) lifestyle where every training session ate away a bit more of my vitality.

I’ve run races where one staple long run per week and several strength and conditioning sessions left me feeling strong, powerful, and fast. My top ten finish at Virgil Crest 100 was the result of a once per week long run and a short, easy run once per week, along with tons of cross training. The long run got up to 50 miles at the height of the training block, with a gradual build up similar to what I’m going to lay out below.

In this last full length installment of How to Run 100 Miles my hope is to leave you with a sense of a “choose your own adventure” roadmap that gives you agency over your own body and how you choose to adapt, along with a template to follow to leave no question about a particular path that is designed to bring you to the finish line of your upcoming race, and many more to come.

This training plan will prepare you for a STRONG 100 mile finish.

You may choose to adopt a higher mileage approach which incorporates 40, 50, 60, or 70 plus miles of running per week. There are a TON of generic training plans available that pile on the miles. I’ve seen people run great races off of these plans. I’ve seen people get injured, burned out, and have their running careers cut short as well.

This isn’t a disclaimer. It’s an encouragement to try things and get increasingly honest about how they are working, and for how long.

You may take only the strength component of this program and incorporate it into a running plan with more of an emphasis on long, slow distance. You may just snag the core training components. I say all of this not to discourage you from doing the program as written, but because I’ve trained dozens and dozens of endurance athletes over the years and I know how personalized approaches to training naturally occur. It’s easy to follow a high mileage program because it’s simple. It’s only one activity-running.

When adding an in-depth 3 day per strength training program I’ve seen certain athletes get overwhelmed by what to prioritize. They prioritize what “looks like” the sport itself as opposed to the weak links in the chain that ultimately undermine the ability to enjoy the sport.

The question I challenge you to ask throughout the program is a.) how do you want to feel and perform this season and b.) what role does running play in your life? Is it a social outlet? Is it a dedicated timeblock to be alone with your thoughts and in love with the art of movement? Is it something that you look forward to? Is it part of your identity? c.) how long is long? Are you planning to train and race for years? For decades? Endurance to us means going the distance for the rest of our lives.

All of these things will determine which path you choose to take to the finish line.

However you choose to implement the program my goal for you is that you feel EMPOWERED and in love with the art of running. There are many paths to the summit and as long as you’re choosing the path that inspires you it’s going to be a hell of a journey

Enjoy the training process-and tune in on Friday’s at 9am as me How to Run 100 Mile participant, coach, and ultramarathon savage Kate Woodard and I answer questions and share experiences in our new, live, Trail Talk/Real Talk series!

The live series begins on February 11th on the Physiology First University platform-link will be sent to everyone who signed up for the program.

This is a sketch of the program that I will use to prepare for the next 3 months.

One long run per week, graduating in distance until I reach a mountain 50k on terrain similar to the race I’m running. A 50k mountain run in the White Mountains (this awesome report details the Pemi Loop run that many of our athletes at The Distance Project use for 100 mile training.

4 strength training and conditioning sessions per week based on my goals.

2–3 short, easy paced runs per week.

Training schedule:

Week 1: 13 mile mountain/trail run.

Week 2: 15 mile mountain/trail run.

Week 3:18 mile mountain/trail run.

Week 4: 20 mile mountain/trail run.

Week 5: 10 mile mountain/trail run.

Week 6: 18 mile mountain/trail run.

Week 7: 20 mile mountain/trail run.

Week 8: 22 mile mountain/trail run.

Week 9: 24 mile mountain/trail run.

Week 10: 26 mile mountain/trail run.

Week 11: 50k mountain run (estimated time on feet-10 hours.)

Week 12: 15 mile mountain/trail run.

Week 13: Taper/ Easy paced ten mile run

Week 14: Race Day

This is a template based on incremental graduations in mileage and deload week added after week 4 and before race day.

I’ve used similar plans to run races that I’m proud of and have found the mileage to be more than sufficient for a.) testing and refining gear choice. This is an often overlooked element of training. It is possible to run a 100 mile race on much less mileage but I want to trail test my gear/nutritional strategy/system’s for storing poles/first aid/extra food etc as much as possible to be totally dialed in on race day. It is more than sufficient for the development of muscular endurance. Aerobic capacity is a non issue as aerobic development is the result of breathing through the nose at increasingly higher workloads to increase oxygen consumption and utilize fat as a primary fuel source. The role that these Sunday (for me) long runs plays in my life has been extremely additive. This is a system that works for me, my goal, and my lifestyle while not placing an unnecessary amount of stress on the body that makes my endurance goals short lived. Endurance to me means playing in the mountains and trails for years-and performing better consistently as I dial in the skill of running and the requisite lifestyle components (stress management/sleep/nutrition) to assure an optimal recovery window.

Can you run more than this? Sure. Can you run less than this? Absolutely. I’ve seen athletes complete ultramarathon races on minimal mileage because they were absolute beasts in their cross training and did not have a competitive running goal. They simply wanted to feel strong, achieve the desired distance, and get back to kicking ass at other things like BJJ, weightlifting, CrossFit, or whatever got them excited to pursue .

The strength development days for me will be focused on 4 full body training days with two devoted to pure strength training on a periodized program and two incorporating higher intensity conditioning workouts. We will share ideas for creating conditioning workouts that accompany this program on the Trail Talk/Real Talk series as well as the Physiology First In Action Live Learning Labs.

Below you’ll find our staple Endurance Redefined program with an additional long run added to each week. This blend of low volume, straightforward strength training, low mileage with a focus on aerobic development during the week, and a slightly longer run each weekend is designed to leave you feeling fast, springy, strong, and increasingly injury proof.

This program was originally designed in conjunction with our Race for the Future ultramarathon event so pardon the references to the race. Endurance coach Guy Petrizzeli collaborated with us to design a 10 week speed development program which starts midway through the Endurance Redefined training block. We felt that it was an awesome addition to the How to Run 100 Miles program as the emphasis on speed development coupled with a weekly long run is a perfect combination for ultramarathon success!

*When choosing your terrain for the long runs be sure to mirror the terrain of your race to the greatest extent possible, if possible :)

Endurance Redefined: Block One (4 weeks)

Week One Modifications:

Reduce 15/45 run to one session. Add one additional 5 mile run.

Long Run Week 1: 13 miles.

Week Two Modifications:

Reduce 15/45 run to one session. Add one additional 8 mile run.

Long Run Week 2: 15 miles.

Week 3 Modifications:

Reduce 15/45 run to one session. Add one additional 9 mile run.

Long Run Week 3:18 miles.

Week 4:

Reduce 15/45 run to one session. Add one additional 10 mile run.

Long Run Week 4: 20 miles.

Endurance Redefined: Block Two (4 weeks)

Week 5 modifications:

Reduce 15/45 run to one session. Add one additional 7 mile run.

Long Run Week 5: 10 miles

Week 6 modifications:

Reduce 15/45 run to one session. Add one additional 12 mile run.

Long Run Week 6: 18 miles

Reduce 15/45 run to one session. Add one additional 13 mile run.

Long run Week 7: 20 miles

Reduce 15/45 run to one session. Add one additional 13 mile run.

Long Run Week 8: 22 miles

Endurance Redefined: Block Three (4 weeks)

Long Run Week 9: 24 mile mountain/trail run.

Long Run Week 10: 26 mile mountain/trail run.

Long Run Week 11: 50k mountain run (estimated time on feet-10 hours.)

Long Run Week 12: 15 mile mountain/trail run.

Endurance Redefined: Block Four (4 weeks)

Long Run: 15 miles

Long Run: 13 miles

Long Run: Easy run in the 5 — 8 mile range

Race day!

Stay in touch as you progress through the program and tune into our Live Learning Labs on Physiology First University to dive into all of the components that make a complete training system. I’m excited to see how you progress through each stage of the program so please keep me posted on your progress and reach out with questions anytime!

Much love from The Distance Project Team and happy trails!



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