ironman – 80/20 Endurance


There is a consistent pattern in my coaching of endurance athletes that I wasn’t conscious of until quite recently. When I coach amateur runners for marathons, more often than not I increase their training volume relative to their past habits. But when I coach amateur triathletes for Ironman events, quite often I have them train less than they have in the past. Upon reflection, I recognize that I do so for the obvious reason: I see a lot of marathon runners who, in my assessment, can both tolerate and benefit from training more, and I see a lot of Ironman triathletes who, I believe, would feel better, recover better, and ultimately perform better if they trained less.

Obviously, the two events, marathon and Ironman, are far from equal. In the former, you run 26.2 miles. In the later, you also run 26.2 miles—after swimming 2.4 miles in open water and bicycling 112 miles. Because an Ironman is significantly bigger and more challenging than a marathon, it selects for a different population of participants. Generally speaking, Ironman participants are willing to invest a lot more time and effort into training than are marathon participants. Not infrequently, I encounter runners who want to qualify for Boston yet balk at the idea of running more than four or five times a week. No less frequently, I encounter triathletes whose marriage is under stress because they habitually spend all of Saturday riding their bike instead of taking the family to the county fair.

I don’t mean to paint with too broad a brushstroke. There’s plenty of overlap between the two populations. Many a marathon runner signs up for a marathon in pursuit of a fresh challenge. Typically, when an athlete makes this leap, they increase their training volume, which is sensible. Indeed, they more or less have to train more, given the three-discipline nature of triathlon. But they are also able to training more, as both swimming and cycling are less stressful physiologically than running is. Ten hours per week of balanced triathlon training are not as hard on the body as 10 hours per week of running.

The mistake that a lot of triathletes make, though, is assuming they will get the greatest possible benefit from the highest volume of training they are willing to take on. If 14 hours per week doesn’t get them to Kona, they try 16 hours, taking it as a given that the increase will yield improvement. If 16 hours per week doesn’t get them to Kona, they try 18 hours, and so on. Experience has taught me that this approach is flawed. I firmly believe that athletes should feel pretty good most of the time throughout the training process, and in case after case, triathletes I work with feel better when I reduce their training volume from the level they had tried to maintain before I got my hands on them.

And wouldn’t you know it, a new study in the journal Physiology & Behavior offers empirical validation of my experience. Ninety-nine triathletes completed a survey comprising questions about training, experience, anthropometric characteristics, and other factors prior to their competing in an Ironman triathlon. The respondents were statistically separated into three groups: those who trained less than 14 hours per week, those who trained between 14 and 20 hours per week, and those who trained more than 20 hours per week. Check out the average finish times for members of the three groups:

<14:00/week 11:28:46
14:00-20:00/week 11:37:31
>20:00 week 11:30:18

That’s right: No differences! What does this mean? A scientist would be careful topping out that it could mean any of a number of things. But I’m not a scientist, so I’ll go ahead and tell you what it means: It means that 14 hours of training per week, give or take, is the optimal amount for most amateur triathletes. In fact, the scientists who conducted this study came to the same conclusion, noting that subjects who reported unintentional weight loss, lack of energy, and decreasing performance before the race recorded significantly slower finishing times.

Interestingly, the authors also found that more experienced triathletes achieved faster Ironman times regardless of how much they trained. One possible explanation for this finding is that, through trial and error, these athletes had found their individual sweet spots for training volume. That was certainly the case for me when I prepared for Ironman Santa Rosa in 2019. Although I had done only one prior Ironman, I had been training for and competing in endurance events of various kinds for many years, and I knew my body well. Based on this knowledge, I maintained a consistent training volume of 14-18 hours per week, with only one week exceeding 20 hours (and just barely). I felt consistently good throughout the process, and upon completing the race and looked back, I felt confident that I would not have fared any better if I’d trained more.

I’m not suggesting that the above numbers represent the sweet sport for all recreational triathletes during Ironman training, though I would speculate that they fall close to the median. The take-home lesson of this article isn’t that recreational triathletes should never bother training more than 14 hours per week during Ironman prep. Rather, it’s that you should be wary of training at too high a volume, as many triathletes appear to do. You will perform best in your Ironman events if you train at the highest volume at which you consistently feel good, whatever that number may be.

First Look at Ironman® California
ironman california

The newly-announced Ironman California has infused some much-needed excitement into the 2021 racing season. The inaugural Sacramento event will take place on October 24, and while a new Ironman course always generates some buzz, this venue has all the components to be the fastest on the circuit. Coach David was part of a limited group of coaches who met with the Ironman organization to preview the course. While these plans are preliminary, and subject to change, we’re pleased to be able to share what we know so far.

The river swim will be fast. The point to point swim, at the confluence of the American and Sacramento rivers is beautiful and quick. Elite to beginner swimmers will be into T1 in record time.

Tower Bridge, California

The Tower Bridge is under consideration as part of the run course. A working drawbridge, Coach David recommend it be used to enforce the cutoff time. Regrettably, this idea was summarily rejected.

The bike might be flatter than Ironman Florida. With tempting hills just outside city limits, old-school athletes may be salivating for some killer climbs and decent descents. But this course is designed for speed. Spurning the nearby foothills, one of three potential courses will take the athlete south of Sacramento. Current options have a total ascent of just 650 to 900 feet. Get ready to get low and stay low.

The run will be urban and energetic. Run courses under consideration include a significant amount of time in or near downtown. You’ll have nowhere to hide on this run course, as friends, family, and total strangers push you to your Ironman personal best time.

The date is ideal. Start your Ironman training in April and take advantage of exemplary outdoor weather (with apologies to our colleagues in the southern hemisphere). Add a spring event to your calendar and Ironman California becomes the perfect second “A” race of your 2021 season.

Sacramento accommodation options are outstanding. A city designed for visitors, few events have the ability to stay so close to the start and finish line. From luxury to economy, you’ll find a room that meets your proximity and budget requirements.

This event will sell out. Be prepared to register soon. Registration opens on Monday (tomorrow!) at noon Eastern Time.

Did we mention that all of this is is preliminary and subject to change! Well, it is!

The August 2009 issue of Triathlete Magazine featured an article titled “The end of Running Injuries.” Written by yours truly, the piece introduced readers to the Alter-G antigravity treadmill, which, I claimed, “has the potential to completely eliminate traditional injury setbacks from the life of any runner (or triathlete) who has access to a machine.”

This hyperbolic-sounding statement was based on my personal experience of testing an Alter-G at a Los Angeles physical therapy clinic. While on the machine, which allows the user to run at anywhere between 20 and 100 percent of his or her full body weight, I could not imagine a single injury I’d ever suffered (and I’d suffered them all) that I couldn’t have trained through uninterruptedly with one of these babies. Of course, injured runners can usually ride a bike and can almost always run in a pool, but unlike these traditional cross-training activities, running on an antigravity treadmill is not an alternative to running—it is running!

The one big drawback to the Alter-G, as I noted in the same article, is accessibility. Although the cost of the cheaper consumer models has come down substantially over the last decade, they’re still far more expensive than a regular treadmill. You can rent time on a machine at some high-end endurance training facilities and physical therapy clinics, but that cost adds up too. Plus it’s a hassle. I’d have to drive 20 minutes each way to access the nearest machine in my area.

Not long after my Alter-G experience, I read a scientific paper that inspired me to try steep uphill treadmill walking as a sort of poor-man’s version of antigravity treadmill running and found that it worked pretty well. It gets your heart rate up, the movement pattern is very similar to running, and it’s a low-impact activity rather than a nonimpact activity, so it helps maintain tissue adaptations to repetitive impact, making for a smoother transition back to normal running than you’d get from cycling or pool running.

While training for a recent Ironman I did a ton of steep uphill treadmill walking because, yet again, I was unable to run due to injury. As race day drew closer and closer and I kept failing the occasional test runs I did, I became increasingly worried that I was running out of time to get my running up to snuff. That’s when I got the idea to try steep uphill running. At a steep enough incline, running generates scarcely more impact force than walking does. My plan was to first see whether my injury could handle a slow jog at a 15 percent incline, and if it could, to then gradually run faster at progressively lower gradients until I was able to run normally again. In this way I wouldn’t have to wait any longer to start building up my running fitness but at the same time I wouldn’t hinder the healing process.

Long story short, it worked. Twelve weeks before my race, I took the final step in the process, from running at a 4 percent incline to running outdoors. Even then, though, I was unable to run faster than about 9:30 per mile without pain. Knowing I wasn’t going to get very fit running 9:30 miles, I continued to perform my higher-intensity runs on the treadmill, which I could do without hindering my recovery if the incline was sufficiently steep. Six weeks before the Ironman, I ran the Modesto Marathon, finishing in 3:30:46 (8:02 per mile) with moderate pain. Two weeks later, I ran the Boston Marathon in 2:54:08 (6:39 per mile) with only mild pain. Two weeks after that, I won a half marathon in 1:17:58 (5:56 per mile) with zero pain. And two weeks after that, I raced Ironman Santa Rosa, completing the marathon leg in 3:17:02, which was about what I would have expected if I had never gotten injured in the first place.

To be clear, a lot of the actual fitness that enabled me to make such rapid progress came from cycling. I was on my bike seven to nine hours per week throughout this period. But I doubt I would have performed as well as I did in the Ironman if not for uphill treadmill running, which functioned as a bridge back to normal run training. Neither walking nor elliptical running nor pool running would have done that for me.

Want to give steep uphill treadmill running a try? Excellent. First, go and get yourself injured. Next, hop on a treadmill and find the shallowest incline that allows you to run without pain. If it’s quite steep (15 percent or close to it) and you’re not a very fast runner, you might not be able to run at any speed without workout really hard. In that case, start with intervals, alternating short running bouts with walking. When you feel ready, lower the belt angle a few degrees and give that a try. If you can run pain-free at this new incline, do so until you ready to lower the belt again, and so on until you’re back to normal running. 


What does it mean to have a talent for running or cycling or other endurance sports? Generally, we think of it as a natural capacity to maintain high speeds for prolonged periods of time, a capacity that is physiologically rooted in what we can loosely call aerobic power.

There is no question that you aren’t going to qualify for the U.S. Olympic Trials Marathon or become a Cat I cyclist without exceptional natural aerobic power. But I don’t believe that aerobic power is a complete definition of endurance talent. Indeed, I can name three other talents that, if not quite as important as aerobic power, also make a significant contribution to endurance performance. These are trainability, durability, and racing sense. Let’s briefly review all four kinds of endurance talent.

4 Kinds of Endurance Talent

Aerobic Power

Recently, the Journal of Sports Science & Medicine published a comprehensive review of past research on the genetic underpinnings of elite marathon performance. A team of scientists led by Hannah Moir of Kingston University identified 16 polymorphisms in 14 genes that appear to have a strong association with elite marathon performance. Ten of these genes “code for transcription factors and coactivators primarily involved in metabolic pathways (i.e. adenosine triphosphate (ATP) generation, glucose and lipid metabolism, mitochondrial biogenesis, thermogenesis, angiogenesis and muscle fibre type composition).” In other words, these genes support the physiological machinery that enables a runner to release energy from metabolic fuels at a high rate with the aid of oxygen.

Three of the remaining four genes “code for enzymes involved in cardiovascular function such as blood pressure and vasodilation.” This essentially means they also support aerobic power but do so through a different type of mechanism. Only one gene among the 14—COL5A1—contributes to marathon performance in a way that has nothing to do with aerobic power. Specifically, it endows elite marathon runners with the stiff joints that enable their legs to function as highly efficient springs.

The authors of the review stress that what we currently know about the genetic underpinnings of elite marathon performance is a drop in the bucket compared to what we don’t yet know. Nevertheless, it’s clear from what we do know is that it’s mainly about aerobic power.


There’s an important distinction to be made between what I call built-in fitness and trainability. Built-in fitness is the baseline performance capacity that is conferred by certain combinations of genes. In other words, it is pre-training fitness. Trainability is the ability to gain aerobic fitness in response to training. The genes that confer trainability are distinct from those that underlie built-in fitness. Some athletes have a high level of built-in fitness and yet training doesn’t make them much fitter because they lack the genes for trainability. Others have a low level of built-in fitness but get a lot fitter through training. Still others have neither built-in fitness genes nor trainability genes, while elite endurance athletes, of course, have both.

The good news is that scientists have determined that trainability genes are quite widespread in the human population—much more widespread than the gene combinations that confer a high level of built-in fitness. In one study, a team led by Claude Bouchard of the Pennington Research Centre’s Human Genomics Laboratory created a system for scoring trainability based on how many of the relevant genes an individual had. While there was a high degree of interindividual variation, a significantly greater number of subjects (52) had the highest possible score than had the lowest (36).

Other than genetic testing, the only way to find out if you have a lot of trainability is by training progressively over a long period of time and seeing what happens. I advise all athletes to assume they are highly trainable until and unless events prove otherwise!


Having a high level of trainability won’t do you much good if you can’t stay healthy long enough to take advantage of it. Although many overuse injuries are caused by correctible factors such as inadequate rest and excess bodyweight, research indicates that some athletes are more predisposed to injury than others. For example, some studies have found that different variants of the COL5A1 gene mentioned above predispose athletes to joint injuries, and a 2013 study found that certain variations were associated with the risk of muscle cramping in a marathon.

Other research suggests that differences in neuromuscular control also play a role in injury risk. Specifically, some athletes exhibit a greater degree of variation in their movement patterns than others do, a characteristic known as redundancy. Neither conscious nor noticeable to the naked eye, these variations spread around the stress of a repetitive activity such as running, reducing the likelihood of tissue breakdown.

Obviously, if you have particular genes or neuromuscular wiring patterns that predispose you to injury, there’s nothing you can do about it. This is frustrating for injury-prone athletes like myself, but instead of brooding on it, take advantage of all the factors you can control to minimize injury risk. These include cross-training, not training through pain, and using the right gear in the right way.

Racing Sense

The most overlooked and underappreciated endurance sports talent, in my estimation, is what I call racing sense, which is the ability to distribute your effort over the course of a race in such a way that you reach the finish line in close to the least time possible given your current physical capacity. It is a largely psychological talent that depends on the ability to 1) comprehend abstract distances (a horse may have horse sense, but it could never pace a marathon effectively because horses lack the brain power to comprehend abstract distances), 2) interpret perceived effort in a highly nuanced way (e.g., knowing how you should be feeling 83.77 miles into the bike leg of an Ironman), and 3) suffer.

Racing sense is generally thought of as a skill, and it is, but it’s a skill in the same sense that being able to throw a football through a 20-inch ring from 25 yards away is a skill. Sure, everyone gets better at it with practice, but some folks are just naturally good at it—better than others with any amount of practice.

As a coach, I never cease to be amazed by how bad most endurance athletes are at pacing. I’ll give you an example. Back in August I attended an annual adult running camp hosted by pro runners Stephanie and Ben Bruce. On the afternoon of the first full day, all 35 attendees ran a short time trial up a steep hill. None of us had ever run the hill before, but we did get a chance to size it up when we rode up to the finish line in vans and then jogged down to the start line. On the word “Go!” we launched. Two young bucks took off at a dead sprint, an insanely stupid decision, in my judgment, given the length (about 700 meters) and pitch (about 12%) of the hill. Meanwhile, I felt my way to the highest speed I felt I could sustain the whole way, passing the young bucks in the final 100 meters and winning a race I almost certainly would have lost if every runner had equal pacing sense.

So, What’s Your Point?

Too many endurance athletes believe or assume they don’t have talent. This bothers me, because I think it’s a self-limiting mindset that often lacks a solid basis in fact. As we’ve seen, endurance sports talent is not one thing—it’s four things, and chances are you’ve got at least one of them in some measure. My hope is that, in reviewing the four endurance sports talents with me, you will better appreciate your talent(s) and perhaps shift your approach to chasing improvement as an athlete.

One of my all-time favorite short stories is “Fantastic Night,” written by the great Austrian fiction master Stefan Zweig in the early 1920’s and set in late Bell Époque Vienna. It concerns a wealthy 35-year-old baron, an orphaned inheritor of a large fortune and dedicated gentleman of leisure who leads a pleasant but unfulfilling life of bohemian comfort that is blissfully interrupted one fateful night in June 1913, when a chance series of events triggers a dramatic internal transformation. Of his pre-awakened self the baron writes, “I can say with certainty that I felt myself by no means unhappy at the time . . . But the very fact that I had become accustomed to getting all I asked from destiny, and demanded no more, led gradually to a certain absence of excitement, a lifelessness in life itself.”

The baron’s transformation begins during an afternoon at the horse track, when the baron comes into possession of another man’s betting slip and finds himself suddenly and uncharacteristically caught up in the excitement of the particular race it pertained to. That the horse chosen by the rightful owner of the betting slip wins only intensifies the strange spell he’s under, an intoxication of the spirit that sends him careening through the seedier parts of Vienna, hobnobbing with prostitutes and shakedown artists and eventually giving away all his money to strangers as he wanders home in the wee hours.

“There was some kind of delirium in me, an outpouring like lovemaking,” the baron recounts, “and I knew a freedom I had never known before. The street, the sky, the buildings, all seemed to flow together and towards me, giving me an entirely new sense of possession and belonging: never, even in the most warmly experienced moments of my life, had I felt so strongly that all these things were really present, that they were alive, that I was alive, and that their lives and mine were one and the same, that life is a great and mighty phenomenon and can never be hailed with too much delight. It is something that only love grasps, only devotion comprehends.”

Ostensibly written four years after these events took place, the baron reports that the spell he fell under on that night never abated, but was only the beginning of a permanent awakening. What’s most interesting to me about the tale is that, according to the baron, this internal transformation led to no outward changes in his lifestyle. He continued to live the same dissipated life of play, following the same routines he had previously, and yet he experienced them entirely differently, relishing the same experiences that before had just barely sufficed to ward off ennui.

In glib modern terms we might refer to the narrator’s new mindset as an attitude of gratitude. At any given moment in our lives, some things are good and others not so good. There may be five good things and five not-so-good, nine good things and one not-so-good, or one good thing and nine not-so-good. The point is, as long as you’re still breathing, there’s at least one good thing about your present situation. And regardless of the balance between good and not-so-good, each of us has the power to focus more on the good than on the not-so-good. This is the attitude of gratitude, and when you have it, any situation you may find yourself in will be more pleasant, and not only that, but the situation will be more likely to improve.

I’m not just making stuff up. The effects of expressing gratitude have been heavily researched by psychologists, and the benefits are clear. For example, a 2015 study conducted at UC Berkeley found that counseling coupled with “gratitude writing” improved mental health in college students seeking psychotherapy services more than either counseling alone or counseling coupled with “expressive writing.”

I myself got a powerful lesson in the value of gratitude during my first Ironman in 2003. Everything went wrong in that race. Less than a minute into the swim, my watch was torn off by a flailing competitor. Less than a minute later, I suffered a vicious calf cramp that brought me to a dead stop in the water. A few miles into the bike leg, I was hit with a bullshit three-minute stand-down drafting penalty. By the end of the bike leg, the pain in the calf muscle that had cramped earlier had spread throughout my entire right leg. During the subsequent marathon, the pain intensified before slowly morphing into a sort of scorching numbness, like when a limb falls a sleep. I got so bad that I couldn’t feel my foot touching the ground and had to run looking down to keep from falling.

In short, I was pretty miserable. But at some point my better self slapped my self-pitying self across the cheek and said, “Get ahold of yourself!” I made a conscious effort to catalog the aspects of my situation that were good. I felt gratitude for the lovely September weather in Madison, Wisconsin, for the pleasantness of the racecourse, for the cheering spectators, for my fitness, and for the presence of my family, who had flown in from all over the country to support me. At that moment my perception of the race changed completely. I started having fun, and I pulled out of my performance nosedive, managing to complete the marathon with dead-even splits.

Ever since that day I have made gratitude an everyday tool in my personal sports psychology toolkit. When I start to brood on what is not so good about a workout or the state of my body or whatever else, I shift my attention instead to what is good, and it helps every time. Do you express as much gratitude as you could in your athletic endeavors?

My 2010 book RUN: The Mind-Body Method of Running by Feel includes a chapter titled “Winging It” in which I advocate—for experienced athletes only—the practice of training without a formal plan. I don’t go as far as to recommend that athletes completely make up their training as they go along. Rather, I suggest they establish certain parameters based on accepted best practices and their individual training history and then fill in the details as they go along, based on where their body is at the moment.

This is exactly the approach I’m taking to preparing for Ironman Santa Rosa 2019. I have an implicit understanding of the path I intend to take over the next six months, but I do not have a single session scripted in advance on my Final Surge calendar. I am fully aware that this approach is not one a majority of athletes could pursue successfully, but I’m confident in it for myself because I’ve been doing it for years, albeit mostly in running.

A number of years ago—in fact, around the same time RUN was published—I profiled professional triathlete Meredith Kessler for Triathlete. I spent a day with her in San Francisco, and over dinner she told me something I’ve never forgotten: “I can drop in an Ironman at any time of the year if I want to. I’m even-keeled the whole year. I don’t have an off-season. I don’t really even taper. It never feels up or down. When [coach] Matt [Dixon] tells me, ‘You have a 10-day block,’ I look at it and say, ‘That looks like the same thing I just did.’”

It’s not the only way to train for Ironmans, but Kessler’s always-ready method really worked for her, and I’m adopting a version of it in my current preparations. Even though my race is more than half a year away, I’ve done three 100-mile bike rides in the past six weeks. The idea is to make the Ironman distances seem ho-hum, something I can do comfortably any day I please.

The one bit of structure that is absolutely vital if you’re going to make a good go of always-ready, winging-it Ironman training is a sensible weekly workout routine, or microcycle format. The one I’m using is actually two weeks in length, and it looks like this:

Mon Tue Wed Thu Fri Sat Sun







+ Transition Run



Intervals or Tempo



Hills, Intervals, or Tempo


+ Transition Run






Long Ride


+ Transition Run



Long Run



Intervals or Tempo

Strength Swim


Tempo or Intervals

Strength Swim




Mon Tue Wed Thu Fri Sat Sun




+ Transition Run



Intervals or Tempo



Hills, Intervals, or Tempo


+ Transition Run



Medium Long





+ Transition Run



Medium-Long Bike + Medium-Long Run

Easy Ride, Easy Run, or Rest


Intervals or Tempo

Strength Swim


Tempo or Intervals

Strength Swim



You’ll see that a two-week microcycle is necessary for me because I wish to bike every other day and run on alternate days, such that I bike four times and run three times and bike three times and four times in alternate weeks. A two-week microcycle is also required by my preference to do a long bike ride and a long run every other weekend and a long bike-run brick in place of separate long rides and runs on alternate weekends.

Another salient feature of this schedule is that I do a transition run after every single bike ride. I see this practice as a powerful and efficient way to boost triathlon-specific running fitness. I haven’t actually begun to put this practice into effect yet because I’ve been hobbled by a groin issue that affects my running and because it’s early, but I’ll start soon.

Of course, I won’t do exactly the same workouts in every microcycle. You can’t get fitter by doing the same thing over and over and I’m currently far from the fitness level I plan to be at next May. My cycling volume is already fairly high, but my swimming and running volume are not and will have to increase significantly in the months ahead. My moderate- and high-intensity sessions in all three disciplines will also get a lot harder. It probably goes without saying that approximately 20 percent of my swim, bike, and run training will be done at these intensities!

I’ll probably peak somewhere around 9,000 yards of swimming, 200 miles of cycling (in four-ride weeks), and 50 miles of running (in four-run weeks) per week. Not super-high volume, but as a highly experienced, older, injury-prone athlete, I neither need nor can tolerate super-high volume.

So, that’s the plan.

Hi David,

I hope you are well. I was excited to receive your email about the addition of 80/20 ironman plans with running power targets. I’m currently using the level 3 Pace and Power ironman plan, but would love to try the power and power plan. Is there a way to get access to this without having to pay the full price of the new plan? Perhaps I could pay half, for the addition of the running power structured workouts?

Also I was wondering if you had any guidelines/advice in regards to electrolyte supplementation during an ironman (e.g. an hourly electrolyte target during)? I’m 62kg, 174cm, I think an average to high sweater, and my exercise clothes do generally have white salt marks after a session, particular when it is hot. Any advice/guidance you can give me would be greatly appreciated.

Warm regards,


Dear LH,

Great to hear from you. I’m really pleased that we have these triathlon Run Power and Bike Power plans available. All of your 80/20 plans allow for a complimentary switches between levels and intensity types, so you can have this one for free. Please use coupon code [redacted] for a 100% discount off of the IM L3 Power and Power plan.

Regarding electrolytes, I have a short answer and a longer answer. Short answer: 300-500mg per hour on the bike is a safe dose. The electrolytes in your nutrition probably already have something close to this and additional supplementation may not be necessary.

Longer answer: There is no empirical evidence that electrolyte supplementation is helpful for endurance athletes, and no evidence that it reduces the risk of cramps or improves performance (see There is also no evidence electrolytes in moderate doses are detrimental, so feel free to try it.

To illustrate, attached is an example of electrolyte concentrations and IM performance. In this particular study, there was no statistically significant difference in electrolyte concentrations between Ironman crampers and non-crampers (controls). Also consider Tim Noakes phenomenal book, Waterlogged for more on the subject.


Matt and I periodically publish anonymously your inquiries to us, particularly when the answer may benefit the community. Have a question about 80/20 training or training in general? Feel free to e-mail me. David W.

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