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7 MAY 2026

Chris’ note—in today’s Infirmary episode, Chris sits down to talk with the legendary triathlon and cycling coach Joe Friel, and our freewheeling discussion spent a fair amount of time talking about a term that’s been en vogue recently, but has been used by coaches for decades: durability or fatigue resistance. Kolie Moore at Empirical Cycling has done some great work on the topic, too, but the fact remains: durability/fatigue resistance is THE ability that will determine how your endurance event goes. It’s always nice to swing a big FTP around, but if your fatigue resistance sucks…you’re going to be walking the run, or getting dropped later in your race.

Functional Threshold Power (FTP) has long been the god statistic when talking about cycling performance. Strike up any casual conversation about training with cyclists, and soon enough the subject meanders around to comparing FTP size. Mine’s 370 right now, says Broheim, confidently, as he’s tossing a leg over his Pinarello and quaffing the dregs of his pour-over. Unfortunately for Broheim, those three digits don’t mean as much as he’d like them to mean. As the old saying goes, it’s not the size that matters—it’s how you use it. Most cyclists, we opine, arrive at their FTP incorrectly, and then don’t know how to utilize their power threshold effectively. Today we aim to fix that by introducing (re-introducing, really) a more useful concept: fatigue resistance.

Fatigue resistance has been making the rounds recently, as a new generation of coaches try to discern what the best in the world do during races. What those coaches have found is that once you standardize a population of athletes in terms of FTP, the trait that matters most is how long they can maintain certain percentages of that FTP, or how many times they are able to repeat a certain number of hard efforts. The cycling world has been the quickest to adopt fatigue resistance as the metric of choice, with coaches tracking riders’ capacities to perform as close to their fresh numbers as possible when fatigued. When you consider that many cyclists race dozens of times each year (as opposed to triathletes, who often race only a handful of times), and that cycling races are sometimes multi-day affairs, you can see why durability rises to the top of a list of desirable traits...[read more]​

Find Out How Salty You Are May 23rd

Athletes and coaches know that they need to drink water and consume salt during racing to fend off cramps and support performance.

But do you know how much sodium you lose for every liter of sweat you lose?

Some athletes lose less than 800mg of sodium per liter of fluid lost, while some unlucky souls lose 2000mg or more.

And if you don't know what your sodium loss rate is, you'll just be whistling in the dark on race day, using a nutrition "plan" that suits the average athlete.

But you're not an average. You're you!

Campfire Endurance Coaching is now a Precision Hydration Sweat Test Center, and our "center" is a roving Ford Transit Van, the Mobile Testing Vehicle or "MTV" as we are now calling it in honor of the once-great channel of the same abbreviation.

We're holding a sweat testing day on 5/23 at Juniper Swim and Fitness in Bend, OR, but I've only got room for four people to get their tests done.

You'll learn your sodium loss, get a personalized fueling plan for training and racing, and a suggested list of hydration products that will work for you.

So what are you waiting for? Get in here.

As always, thanks for reading.

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Presented by Campfire Endurance Coaching

Today's newsletter is presented by Campfire Endurance Coaching.

We help endurance athletes improve their results (get FASTER), find more joy in the process of getting faster (get HAPPIER), and achieve lifelong wellbeing through sport (get HEALTHIER).

Our company has two major services:

• ​One-to-One Coaching: fully customizable, high-touch coaching built for your life and your goals. Our coaches carry a maximum of 15 athletes so you know you and your goals are always a prioity.
• ​Training Camps and Clinics: immersive multi-day and single-day events aimed at getting you the most improvement in the shortest amount of time.

If any of those sound like something you would like to take advantage of, you should consider booking a 45-minute FREE coaching and training consultation with us​