Schedule

Annual

This is the first week of one of two 24-week macrocycles and one of four 12-week mesocycles. The priorities now are: transitioning to training, and rebuilding capacity.

Weekly

This is a hypothetical schedule. Feel free to shift and rearrange, so long as the higher intensity sessions (for Strength and Speed) are preceded by full recovery.

Sessions

Key

A mountain guide once told me that the first thing he does with a new client is listen to their feet. "If we're on a trail and their steps are noisy," he said. "They'll be a hazard to themselves—and to me—when we get off the trail."

Walking on a sidewalk is a controlled fall. With a leg extended, we're off balance, and the leg catches us. Moving forward precedes contact with the ground.

Without that controlled fall, moving forward would be strange and difficult, like a ninja sneaking into a house. Instead, we let gravity do most of the work and go along for the ride.

But when the terrain gets steep enough or rough enough that we need to lift our leg rather than just swing it forward, falling onto that leg wastes energy. In that case, the force into the ground is greater than the force required to move upward. And especially when there are consequences to slipping, falling forward is dangerous.

The trick is to—rather than reaching and falling—place your foot and then transfer your weight. The order is reversed; contact with the ground precedes moving forward.

On steep trails—and especially with a heavy pack—it feels a lot like being a slow motion weeble wobble. It's not a fall at all, but a slow, back-and-forth tilt between trustworthy platforms.

You can learn the technique in two ways. The first is to walk over rough terrain for hours and hours, for years and years. Efficiency will naturally, eventually show up.

The second way is to practice it by stepping quietly. The more noise that's made, the more effort is wasted. Excess noise means excess force. If all you hear is a tiny crunch of gravel during weight transfer—and not the step itself, or worse, a stomp—then you're on the right track.

Like traveling in the mountains, beginners rush in when it's dangerous and hesitate when it's not. Racing is like the latter.

The desire to be ready creates unnecessary procrastination. If the first race is delayed, the lessons to learn are postponed. Time is wasted, and progression slows. If racing is put off, so is an ideal performance.

Learn by doing.

"No," you might think. "I'll get really fit, and then I'll race."

Fitness is part of it, but not all of it. Racing must be practiced. A smart racer will be able to perform at a higher level than someone who focuses only on fitness. The better racer will win.

Don't wait until you're in top shape before your first race. That only increases nerves by creating an expectation. And then it increases regret when execution is poor. Instead, race when the stakes are low, when you're happy to go slow, and likely to learn something. It'll pay off in better racing down the road.

Ignore your nerves.

Here's how:

From The Science of Winning, p.336

physiological adaptation induced: rise of glycolytic rate = VLamax, PLamax or maximal lactate production rate

...plays an important part in the base training period and, to a smaller extent, in the competition training period where it is mainly used for maintenance purposes.

Preferably, the anaerobic capacity exercises are inserted into the first half of the training session. This type of workout also lays the basis for the tough anaerobic power work that will come up later and must therefore certainly precede the anaerobic power sets.

Training Criteria

Checklist for the anaerobic capacity exercises:

1. short intervals (25-50 m)
2. each repetition must be swum just a little slower than maximum pace
3. the rest must be at least as long as the exertion time span, preferably, even 2 times the exertion time
4. contrary to all other types of training, passive rest is better than active rest

A trick to control the intensity of the anaerobic capacity sets is to insert an all-out sprint early in the set:
- if the time of this sprint is more than 1.5 sec/50 m faster than the previous repetitions then the previous repeats were too slow and the remaining reps have to be swum faster
- if the time of this sprint is less than 1 sec/50 m faster than the previous repetitions then the previous swims were too fast and the remaining reps have to be swum slightly slower

Conversion to Mountain Sports

1. Short intervals of 12-24".
2. Each repetition must be just a little slower than maximum pace.
3. Make rests twice as long as the exertion time—24-48"—and passive.
4. Test the output:
   1. Go all out in the third sprint.
   2. If the effort covers the same distance, but more than 1.5" faster, then the sprint pace is too slow.
   3. If the effort covers the same distance, but less than 1" faster, then the sprint pace is too fast.

From The Science of Winning, p.335

discussion

Since the conversion from pyruvate into lactate and vice versa occurs very quickly, the ratio between the muscle concentrations of lactate and pyruvate is described as being 1/1.

The anaerobic capacity can change as the athlete goes through the training cycle. It is thought that each individual has an innate maximum anaerobic capacity that is genetically determined. However, some coaches and sports scientists have observed growth in this capacity after years of training.

a.k.a.

It is frequently called VLamax (in some literature also PLamax) ... [and] “production of lactate” for what we refer to as “the production of pyruvate”.

units

...expressed in “mmol of lactate per liter and per second” instead of “mmol of pyruvate per liter and per second”.

Responding to my training advice for a skimo vertical, a Redditor asked for clarification on when "intensity" starts. (At aerobic threshold, not anaerobic.) I offer five ways to find it.

Where does intensity begin?

...when you mention 5% [for a 2-hour event], you mean at or above LT2 right? For zone 3 (or in between thresholds) we could do up to around 15%-20% ?

Intensity starts at aerobic threshold.

By "intensity", I mean anything above aerobic threshold (AeT), not anaerobic threshold (AnT).

The gap between the two—aka. Zone 3—is very individual and based on training history. Someone who has spent too much time in Z3 will have a wide gap, while someone with a well-developed aerobic system will have a narrow one. (The worst I've seen is over 30%; the best, less than 5%.)

If you don't know your AeT, you could:

1. Do Scott Johnston's drift test;
2. Get a proper lab test done by a knowledgeable tech (but buyer beware);
3. Try Tymewear (excellent, but the sensor is expensive);
4. Guess at 80% of AnT (not great, but most training volume will always be less than that anyway); or
5. Super worst-case: ignore reality and associate effort with progress, and fatigue with fitness.

Number five is the most popular—and the most destructive for fitness.

Imagine going to a steep skiing film at the Banff Mountain Film Festival. One of the also-ran ski films is playing at a pub, and you're sitting at the back. At the table next to you is a bearded, salt-and-pepper-haired gentleman. His puffy jacket has duct tape covering the holes—and the logo. His face is a mix of a goggle tan and windburn.

"So how long have you been into skimo?" you ask.

If he's nice, maybe he'll smile. If he's not, maybe he'll spit.

The fastest way to be flagged as a beginner is to use "skimo" to describe anything but racing. Long-time backcountry skiers don't use the word unless—like my climber friends—they do it sarcastically.¹

When planning the weekend, experienced backcountry skiers ask, "Skiing Saturday?" The type of skiing is implied. Or if they also frequent ski hills, a distinction may be made with, "Touring on Saturday?" Or via the objective: "What about the 3-4 on Sunday?"

Think of "skimo" as short-hand. "Ski mountaineering racing" was always too much of a mouthful, so it became "skimo racing", and amongst racers—whether or not they backcountry ski—it's "skimo".

• "ski mountaineering racing" -> "skimo racing" -> "skimo"

"skimo" means racing.

What's the difference?

In the spectrum of backcountry skiers, true ski mountaineers are the rarest. Ski mountaineering demands broad mountain knowledge and abilities: glacier travel; rope rescue; scrambling in ski boots; the ability to build anchors in rock, snow, and ice; and avalanche training.

On the other end of the spectrum is the most accessible and popular sub-discipline: ski touring. Avalanche training is still very important—although often lacking—but the knowledge, technical skill, and equipment demands are much less than ski mountaineering. Technical mountain skills are not required.

Skimo racing sits, strangely, in the middle. It's admittedly the geekiest and least similar to its roots, but it is by far the most physically demanding.² As the name implies, most of the mountaineering has been taken out of it.³ And this "dumbing down" of the mountaineering requirements is a very, very good thing. With few to no safety concerns, pure physical performance becomes the priority. With performance as the priority, true limits can be discovered and pushed. Despite popular myths to the contrary, that can't happen in a hostile environment.⁴

1. "But that store Salt Lake is called skimo.co!" you might think. Yes, skimo.co is a great resource for fast and light ski touring equipment. (No affiliation.) But the name comes from being one of the early importers of race gear from Europe, not ski mountaineering equipment in general (until more recently).
2. I say this as an ex-alpine climber, so I'm familiar with the demands of big, dangerous objectives.
3. Although grande course races are often true backcountry races—and the European versions often require true ski mountaineering skills—most of the modern competitive events are organized in and around ski resorts.
4. As with sport climbing, pretend experts sometimes say, "skimo is neither". In all cases, "is neither" only reveals a speaker who can't do either.

1. When starting out, trim your skins longer than you think you need.
2. As your skinning technique improves, you'll be able to trim the skin shorter and shorter.
3. Eventually—for proper, efficient skin tracks—trimming the skin 10-15 cm past the heel piece is plenty.

A few years ago, I went scuba diving for the first time. After monitoring your air supply, the second most important thing to manage is buoyancy. It can invisibly control you, so awareness of it is crucial.

It struck me that buoyancy is a great metaphor for context. The context we choose to train and perform in has the same dynamics.

Three Types of Buoyancy

Buoyancy can be positive, negative, or neutral.

Positive buoyancy is what everyone thinks of when they hear the word. Something less dense than the surrounding medium will rise. A balloon filled with helium will climb toward the clouds. In racing, everyone gets a boost from sideline cheering.

Negative buoyancy is the opposite. Something more dense than its medium will sink. A stone dropped in water will end up on the bottom. In training, criticism and conflict increase the load.

Neutral buoyancy is neither. The object's density matches the medium, so it hangs suspended. A neutrally buoyant diver will hover at depth.

Buoyancy is dynamic.

The interesting thing is that buoyant objects accelerate. Their velocity increases until it's balanced by drag.

Positively buoyant objects rise faster and faster, shooting toward the sky. But like falling objects, negatively buoyant objects descend faster and faster toward the ground.

Without intervention, a scuba diver will rise and sink faster and faster. Like a diver, winning and succeeding often leads to more of the same, as do their opposites.

The Two Hazards of Buoyancy

"Behaviors don’t always reflect personality; they’re more often a function of the situation."
—Daniel Kahneman

The dangers of buoyancy are two-fold.

The first hazard is not recognizing that buoyancy is at work. A lot of effort is wasted if changes in context would create similar, but more sustainable, change.

A common mistake in training is to sacrifice sleep to increase training time. This limits recovery, making the additional training less effective. In contrast, increasing sleep—sleeping longer at night and/or adding naps during the day—supports adaptation and makes additional training possible and more effective.

The second hazard of buoyancy is taking credit for its effects. A certain context may not be the person’s doing—born on Park Avenue vs. born in a war zone—and thinking so can lead to undeserved effects on self-perception and confidence.

In a positive environment, taking credit for context leads to overconfidence and eventual correction. In a negative environment, taking blame for context leads underconfidence and missed opportunities.

Be aware of buoyancy.

"...success is not the result of strong willpower and the ability to overcome resistance, but rather the result of smart working environments that avoid resistance in the first place."
—Soenke Ahrens, How to Take Smart Notes

If situations shape behavior, shaping them can create an advantage. In training and racing, engineer a supportive environment: Sleep as much as possible, prioritize nutrition, kill your commute, connect with cheerleaders, avoid critics. Accept that inputs are controllable, but outcomes are not.

I see parallels between Hintsa's approach to performance and a modified approach to post-traumatic growth.

This July, my wife graduated from the MAPP program at the University of Pennsylvania, so we've been talking a lot about the PERMA framework over the past year. In her capstone project on child loss, my wife proposed reordering PERMA into REMAP, placing relationships first and suspending the positive¹ until it becomes appropriate and possible.

In September, I started a training program with Hintsa Performance. It introduced me to two related ideas, one similar and one new: starting with relationships and engagement in the coaching process; and including vitality (V) as a PERMA component.

The combination of the two approaches triggered the idea of REVAMP. Relationships (R), engagement (E), and vitality (V) all have immediate benefits—regardless of the context of the client—while achievement (A), meaning (M), and positive emotion (P) often take longer, especially in trying times.

1. The idea of "suspending the positive" is from the work of Abimbola Tschetter, my wife's capstone advisor at Penn. In her own work on post-traumatic growth, Tschetter proposed ERMAP as a more realistic approach than PERMA.

Trail Running With (Reliable) Power

Using power as a training metric for trail running is ideal. Pace is best for flat roads, but variable terrain makes that impossible for trail runners. Until recently, an accurate algorithm for running power didn’t exist.

But now it does: Garmin users can use RunPowerModel by Markus Holler. To start using it, add it to your data fields (for free), and set a run-specific threshold.*

Free Coaching & A Well-Being Assessment

Since the early 2000s, I've been training in silence and paying attention to my breathing. Synchronizing cadence with respiration is a reliable way to limit intensity when training and an ideal way to pace a race and produce the highest average speed.

Benefits of Cadence-Driven Respiration

Limit intensity when training.

The trick is to learn which rhythm works with which movement pattern. The real limiter is the duration of a breath cycle, but keeping track of that would be tedious. Thankfully, it's also unnecessary.

These are the rhythms that work for me and the intensities that they match up with:¹

• "Striding" includes hiking and skimo training. It (probably) does not include most ski touring, because the gear is (ridiculously, unnecessarily) heavy and most people's cadence becomes slow and robotic at best.
• The running respiration zones can be often be split with odd numbered cycles. For example, Zone "2a" might be 4-4, while "2b" could be 3-4. "2b" is slightly higher in intensity, but not high enough to warrant "Zone 3".

Pace a race.

At an amateur level, almost every racer starts too fast. And shockingly, many repeat the error every race.

For events that are largely aerobic—anything over two minutes, and espec­ially over four—records are usually set with nearly even splits. The first half is never a lot faster than the first.

To have almost-even splits, the athlete must start feeling that they could go faster, but must choose not to. They ignore the adrenalin, strength, power, and over-confidence they feel at the start. And a great way to make that happen is with breath control.

In a two-hour skimo race, the following pacing strategy has worked well for me:

1. Always, always, always warm up. Skipping a warm up sabotages performance.
2. Off the start line, 2-in, 2-out lets me go out decently fast but without going over my anaerobic threshold.²
3. After 5-10 minutes—when I feel like I'm no longer at risk of going too fast too soon—I switch to 1-in, 2-out for a few minutes.³
4. Once into a good rhythm, I switch to 1-in, 1-out for the majority of the race. From experience, I know that that rhythm is right at my anaerobic threshold. Climbs will be at the right intensity, while transitions and descents will offer a bit of a break.
5. For the final ascent, I go as hard as possible and the 1-1 rhythm becomes impossible to maintain. At that point, I know that I'm over my anaerobic threshold (where synchronized breathing isn't possible), but I should be able to hold that pace until over the finish line.

Three Signs Your Pacing Strategy is Working

Once in a good rhythm, there are a few things that usually happen:

1. Racers you always beat will be right beside you for the first few minutes. They eventually fade.
2. You start to close gaps on the racers that started too fast (and are forced to slow down).
3. You catch your usual cohort around the last third of the race and have a better ability to attack and defend.

1. Do your own tests. Once you know your thresholds, try different percentages of them and see what breathing rhythms emerge.
2. In a training context, 2-in, 2-out is about 95% of my anaerobic threshold. But at the beginning of a race, I suspect that it's slightly higher due to nerves pushing the pace.
3. Depending on the (low) quality of the route-setting, the initial rhythm may have to be accelerated. A proper skimo course has two parallel skins tracks on every climb, but this is uncommon in North America. And if the race briefing doesn't state that slower racers have to step aside for faster—which they should—then a faster pace to the single skin track may be required.

For a lactate curve, three shifts are possible: to the left, to the right, or none at all.

A traditional interpretation of those shifts would be, respectively, a decrease in aerobic capacity, an increase, and no change. But by only considering aerobic capacity, a traditional interpretation is never complete and has a 40% chance of being wrong.¹

"The traditional way to read a curve is that a shift to the right in the curve means ... better endurance, and a shift to the left means deteriorating endurance. The problem with that idea is it is too simplistic."
—Steve Magness, The Science of Running

As Magness suggests, a lactate curve is not a single index. It is a series of balance points between two opposing forces. Each reading represents the tension between anaerobic capacity (pulling the value to the left) and aerobic capacity (pulling the value to the right).

It's the difference between the two.

It's not the absolute strength of either capacity that determines a lactate reading, but the relative strengths of both. Anaerobic capacity increases the amount of circulating lactate and aerobic capacity decreases it. So the observed lactate in the bloodstream is not an absolute value for either, but the difference between the two.

• [La produced] - [La cleared] = [La observed]

Lactate from glycolysis enters the bloodstream where a portion is cleared via aerobic metabolism. What's left behind is what is measured in a lactate sample. So measured lactate is only the difference between the two capacities. It's not a clear indication of the absolute strength of either one.

At a constant speed, changes in blood lactate only reveal that the balance has shifted. On its own, a lactate curve can never explain the reason for its shift. Because of this, 13 possible reasons exist, not three: five for an increase, five for a decrease, and three for no change at all.²

Reasons for a Shift

A shift to the left means that the balance has tipped toward anaerobic capacity, and the difference in lactate has increased. That change could come from:

A shift to the right means that the balance has tipped toward aerobic capacity, and the difference in lactate has decreased. That change could come from:

No shift means that the balance is unchanged, and the difference in lactate has remained the same. That could come from:

The reason can't be known from the curve itself.

It should never be assumed that a change in only one factor—traditionally, aerobic capacity—is responsible. The true cause must be inferred from other factors.³

A lactate curve on its own cannot reveal whether aerobic or anaerobic changes are responsible. Only a complete test protocol can.⁴

1. "...only about 60% of the classic interpretations of the aerobic capacity fits with the more sophisticated valuation. This means that out of five lactate tests classically evaluated, on average two interpretations are incorrect and will inevitably lead to wrong training advice." Jan Olbrecht, The Science of Winning, p.145
2. Jan Olbrecht originally wrote about this apparent paradox in 2000, but the traditional interpretation has persisted long after. For a table that illustrates all 13 possibilities, see page 112 in The Science of Winning.
3. The two capacities—aerobic and anaerobic—can really only be measured in a lab, respectively by VO2max and VLamax. But precise tests are expensive, inconvenient, and interrupt the training process. In contrast, regular Olbrecht-style tests can provide similar information by proxy and without a negative impact on a macrocycle.
4. A complete lactate test must include samples at submaximal intensities—for aerobic capacity—and a near-maximal sample to reflect anaerobic capacity. Olbrecht recommends a full recovery, an all-out 45-90" effort, and then samples until a peak value is observed.
5. The longer an event, the slower the average pace, and the less the anaerobic contribution. So for many mountain athletes, not measuring anaerobic capacity may be lower risk. But tracking the change in both capacities will provide a fuller picture than tracking only one.
6. Regardless of the role of anaerobic capacity during a goal event, training anaerobic capacity is a worthwhile training component for strength, speed, and—according to Olbrecht—to add “spice” to aerobic capacity workouts, increasing the aerobic stimulus.

In 2018

In my first test, WHOOP's biggest issues were:

1. Heart rate readings were roughly accurate, but horribly imprecise.
   Decent accuracy makes it fine for vanity metrics and broad generalizations, but not useful enough to hit specific training targets.
2. The app had no options for personalized thresholds.
   To use a generic zone formula is the first sign of an unsophisticated—and unrealistic—approach to heart rate monitoring.
3. Optical heart rate monitoring is indirect and unreliable.
   This is a broad industry issue with wrist-based monitoring. Of course, it doesn't stop the wealth and fatness industry from selling people gadgets they don't need.

In 2025

Day 1 - June 15

The app now has personalized zones.

This is a great first step. Let's see what happens.

WHOOP can broadcast heart rate, but not receive it?

Fail. If WHOOP would integrate with chest straps, the training data might be much more useful for athletes. At a minimum, just one device would have to be worn.

The combination of all-day wrist monitoring and precise measurement from chest straps during training sessions seems like an obvious bonus. But to do so, WHOOP would have to admit that wrist monitoring is not ideal. (Surprisingly, another part of their app reveals that. Read on.)

Will tracking sleep worsen it?

I don't like the idea of tracking sleep. Almost all of my sleepless nights are from wheel spinning, so tracking my sleep seems like a great way to make that wondering worse.

WHOOP should go after the heat training market.

I'm also testing a CORE. It's mostly a hassle, and doesn't seem worth it. However, for a device that's intended to be worn 24/7 like the WHOOP, tracking heat exposure makes way more sense.

With CORE, the sensor goes on a heart rate strap, so it's only recording during training sessions, and it doesn't allow for manual heat training entries, just passive exposure. (Forgot your strap? Tough.) While training is always session-specific, heat exposure can happen any time, during training or just suffering on the beach. A 24/7 device like WHOOP would be a much more convenient way to monitor heat adaptation.

What does WHOOP classify as an activity?

In the app, activity detection is defined as "sustained, significant cardiovascular exertion"? But...

• 15 minutes is "sustained"? For who? This is a big reveal that WHOOP is really targeting chronic exercisers, not necessarily focused athletes.
• And what defines "significant"? In my 2018 test, cleaning the house triggered a recording.

Day 3 - June 17

Activity detection is weak.

Although personalized zones and thresholds are necessary, WHOOP doesn't adjust its algorithm to account for high levels of fitness.

As someone gets fitter, their training needs to become more polarized. The hard sessions get harder, and the easier sessions get easier. On the easy side, an athlete that starts out with lots of Zone 2 work will need to shift more and more of it to Zone 1 or Zone 0 as the years go by and their speeds increase.

But WHOOP classifies Zone 1 as recovery work, so it doesnt' trigger an automatic activity recording.

Day 5 - June 19

WHOOP admits that wrist monitoring kinda sucks.

In 2018, I only got semi-reasonable data from the WHOOP when I wore it on my arm as tight as possible over my brachial artery.

In 2025, manual activity entries now ask for a device location... The options are: wrist band, bicep band, arm sleeve, compression top, shorts, leggings, underwear, bra, performance tank, swimsuit, cycling bib.

While some of those locations seem much worse than a wrist band, it seems like an acknowledgment that location affects the reading. So why not just integrate with chest straps?

Day 7 - June 21

Recovery metrics don't match energy levels.

On June 19th, I slept nine hours, felt great, and woke up with really high energy levels. But WHOOP Recovery was in the yellow zone with a 66. (I guess yellow means mediocre?)

Last night, I slept seven fitful hours and woke up tired and groggy. WHOOP Recovery was in the green, 77, and posted an atta-boy of "enjoy the increased focus!"

Day 8 - June 22

I did four 25-minute sessions in a track car. (I was surprised to see that WHOOP has an activity option for "motor racing".) While picking up on my stress was accurate, assuming it was a workout is nonsense.

Stress detection is strong.

Although curious what it would register, I didn't look at the WHOOP app until later in the day. I was surprised to see that the timing of the stress measurement matched when I started getting my car ready. (And it was hella hot, which didn't help.) And it picked up on the timing of each track session thereafter.

Stress = Strain = Fitness = Nonsense

While a BMI score may be more universal, fitness is specific to a goal. Equating all Strain with "fitness" is nonsensical. Fit for what? Four track sessions is not going to make me fitter for anything but heat resistance.

Heart rates in amateur racing are in Zone 1 or less, and the elevated rates come from heat, stress, and dehydration, not from physical exertion. WHOOP defines an activity as "sustained, significant cardiovascular exertion," but this is not what happens in a track car. Significant cardiovascular exertion has such a high respiration rate that talking is impossible. Talking while driving—even while racing—is common and easy to do.

Day 9 - June 23

Does activity detection improve?

This morning I did a typical 45-minute Zone 1 run. My pace, breathing, effort level, and heart rate were the same as usual.

For the past week, I've had to note these manually in the WHOOP app, but today it picked up on it accurately. Is it learning?

Day 10 - June 24

Is the web app abandoned?

I haven't checked since 2018, but comparing screenshots suggests that not much has been changed in the WHOOP web app.

I don't like wearing two gadgets.

Because I want to monitor my training with a real heart rate monitor (with a chest strap), I train wearing a watch and wear the watch—but not the strap—even when I'm not. Always having a second gadget on my other wrist is unappealing.

I don't like increasing my phone usage.

I'm always schemeing about ways to use my phone less, not more. So 24/7 monitoring with all of the data in my phone is the opposite type of behavior modification that I'm looking for.

WHOOP is expensive.

WHOOP plans vary between $199, $239, and $359 per year. For (a lot) less than $100, I'd consider it, but without any integration with real training data, it's not worth it. (Wrist-only heart rate monitoring and equating "strain"-ing with training doesn't cut it.)

Instead, it's simple enough to use WHOOP through the free trial and then continnue with the positive behavior modifications: sleep more, avoid alcohol, prioritize recovery.

Day 12 - June 26

Motor racing is not anaerobic...

In a recent summary, WHOOP suggested that motor racing would give me the anaerobic boost that I needed:

Alternatively, Motor Racing offers a high-intensity option that could provide the anaerobic boost you need, with a strain of 10.1.

Track days and racing are stressful, but from heat, dehydration, and decision-making, not from a significant cardiovascular load, and certainly nothing anaerobic. (If you can talk while you do it, the cardiovascular load is low.)

Day 13 - June 27

VO2max estimate seems likely.

I haven't had a VO2 test in five years, but I was always in the low 60s. WHOOP estimates my current VO2 max at 59. I'd be surprised if I didn't have a bigger drop due to age and a lack of training, but my guess would still be in the 50s.

Day 14 - June 28

HRV still seems whack.

If WHOOP is estimating HRV via the optical monitor, then it could be the algorithm that's whack. (Perhaps actually measuring HRV has become more useful.) But what WHOOP is reporting for HRV is inconsistent with how I feel each morning, similar to how it was with ithlete.

Day 18 - July 2

The novelty has worn off.

Reality has set in. Whoop is helpful for nudging behavior in a healthy direction, but in huge contrast to its marketing, it is not a training device.

Final Conclusions

It's helpful for health.

So far—and similar to the first time—the WHOOP does do a good job of nudging me toward healthier choices: avoid alcohol, avoid screens at night, get lots of sleep, prioritize recovery.

But genuine goal-specific fitness? I don't see how generic algorithms can connect the dots between an individual's idiosyncrasies and the maximized performance necessary for a specific goal at a specific time and place.

Fatigue is not fitness.

Equating every "strain" with a training stimulus is absurd. Heart rate itself is a stress metric, but not every rise in heart rate will lead to an increase in fitness. (Waiting to see the principal is not going to make a high school track star any faster.)

But WHOOP seems to not know the difference between a stressor and a stimulus. And without the ability to sync with a real heart rate monitor—and an accompanying setting that says, "only use chest strap input for training stress"—WHOOP's "fitness" metrics are useless.

(But really, I wouldn't be surprised if the inner circle at WHOOP has known this for years, even from the outset. The serious athlete market is microscopic, while the near-sedentary market is gigantic. And that market is primarily concerned with fatness, not fitness, and "straining" is probably enough to improve a person's beach body.)

Consumer devices are for consumers.

Although market-adjacent to—and marketed by—athletes, I doubt that anything but the health and habit functions are useful. For general, beach-ready "fitness", Strain might be enough to look good. But to perform well when you need to, real training technology is required.

What would make WHOOP useful?

Despite the marketing, Whoop cannot help athletes prepare for their goals directly. But Whoop could be a great auxiliary device if it would:

1. Substitute optical heart rate recording when a chest strap is worn. The fact that Whoop records where its worn reveals that they're aware that location has an influence on the quality of the recording. Pairing it with a chest strap—and overwriting the optical data with the chest strap data—would provide a much more accurate picture of the physical load and precise-enough data for training.
2. Monitor heat adaptation. The fatal flaw of CORE is the necessity to designate when heat training is happening. Heat acclimatization happens more frequently than in training sessions. Only recording training sessions will underestimate the process. In contrast, a 24-hour device that monitored body temperature and heat acclimatization would be very useful.
3. Distinguish between "straining" and training, both in data types (optical monitor versus chest strap) and activity types (actual training activities vs life activities). "Strain" might be useful for monitoring life stress, but it's nonsense for training purposes. Likewise, non-sport-specific activities should not be included in the training metrics.
4. Update the web app to be as useful as the mobile app. For a device that nudges people toward better health decisions, it's surprising that they invest much more in a mobile app. Reducing phone usage is a nudge that benefits everyone. However, just like marketing for "training" is better for business than marketing health, investing more in their mobile software likely serves the same purpose. Their design priorities reveal their true motivation.
5. Allow outright purchases. I don't have an Oura ring, but I much prefer their business model. Paying hundreds once and having the device forever is much better than an exorbitant subscription that never ends.

Two tests seven years apart and the conclusion is the same: Whoop has a great business strategy, but it has little in common with goal-specific training or high performance.

Since the early 2000s, I've been training in silence and paying attention to my breathing. The benefits are significant:

1. A quiet effort quiets the mind.
2. Idea generation increases 10-fold.
3. Increased awareness improves execution.
4. Synchronized breathing naturally limits intensity; and
5. Music becomes caffeine.

The best meditate while they train or climb. This active meditation, while similar to passive meditation, connects thought and action, perception and reaction, instead of segregating components.

—Mark Twight, Extreme Alpinism

Benefits of Training in Silence

A quiet effort quiets the mind.

Twenty years ago, my roommate Kim recommended Body, Mind, & Sport, by John Douillard, who champions nasal breathing, recommending it for all types of exercise.¹ It sounded a bit woo-woo, but I gave it a shot.

On an approach to the north side of Mt. Robson, I hiked in with a friend that is notoriously hyper and chatty. I mentioned the nasal breathing to him, and we both tried it.

"How'd it go?" Kim asked when I got back.
"We failed. But I mentioned the nasal thing, and he was quiet for two hours."
"What? No way..."

Idea generation increases ten-fold.

The idea of having your "best ideas in the shower" is a common one, as it is with any borderline-boring, low-stimulation environment like staring out a bus window. Our default mode network gets switched on and starts connecting the dots between thought and experience.

But unless you're a teenager, showers only last 10 minutes and bus rides are rare. And even if you shower every day, 10 minutes a day is only 61 hours per year. If you train in silence, the volume of idea generation—and the rate that they occur—is significantly higher.

Not only does the DMN switch on, but higher-than-resting heart rates turbo-charge its processing. Rather than 61 hours per year at a resting rate in the shower, you have hundreds of hours per year at a much higher rate.

And as an added benefit, training at a DMN-friendly intensity 95% of the time is exactly what you need to build a strong aerobic base.

Increased awareness improves execution.

When running, I used to be a heel-striker. It felt normal, and I never thought anything of it. But after watching a technique video by Bobby McGee, I decided to try and change my running form.

It took a couple of seasons—and a lot of patience—for my calves to adjust to mid-foot striking, but now I can't imagine running any other way.

(To feel the difference, try this: First, walk down a flight of stairs normally. Notice how little impact there is. Now do it again, but pull your toes up to heel strike as you descend. Awful, right?)

When I started skimo racing, my transitions were hella slow. Others would enter and exit a transition zone before me, even if I arrived first. But by practicing slowly, in silence, and focusing on every movement, my transitions are now very competitive. (Any racer can have fast transitions if they practice).

Synchronized breathing naturally limits intensity.

Over the last twenty years, I've become familiar enough with my breathing that I know what intensity I'm at just by tracking my respiration alongside my cadence.²

Ventilation is a more real-time measure of intensity than heart rate, so if I'm running at a 4-in, 4-out ventilation rate, I know that I'm in Zone 1. Or if skinning uphill at 2-in, 2-out, I know that I'm in Zone 2. Or in an uphill race at 1-in, 1-out, I know I'm near anaerobic threshold and have a little more headroom to attack-defend or let it all out at the finish.

Music becomes caffeine.

Training in silence increases the benefit from infrequent, external motivators.

Increasing the association between effort and fatigue³ also sensitizes me to dissassociative tools. So instead of being dependent on any external supports—like someone that needs coffee in the morning just to get to baseline—motivators like music feel incredible when I use them.

Instead of craving the distraction of a podcast to endure every long session, silence is the norm. Instead of being dependent on music to get up to speed, it acts as rocket fuel when I need it.

How to Train in Silence

For the next month, train in silence in all easy sessions. You might need that long to get comfortable with it.

1. Turn off all notifications. (And do so every training session, forever.)
2. Synchronize your breathing and cadence.
3. Immerse yourself in "boredom". Let your mind wander.
4. Mind not wandering? Slow down.
5. Observe your movement patterns. What could you improve?

1. Years later while working with Scott Johnston, we recommended nasal breathing as a natural way to stay below aerobic threshold. But we found that it only worked reliably for athletes with a well-developed aerobic system—those with less than a 10% gap between aerobic and anaerobic thresholds. Athletes with underdeveloped or damaged aerobic systems (usually from too much high-intensity training) could still nasal breathe above AeT. As a result, we stopped using nasal breathing to target AeT.
2. I still wear a heart rate monitor so that I don't delude myself with RPE, but the main driver of intensity for 90% of my training is ventilation.
3. "In a study on triathletes ... the higher pain tolerance was related to higher associative coping skills and lower dissociative skills." (The Science of Running, Steve Magness) Meaning: Increase your ability to deal with discomfort by immersing yourself in it when you don't need to.

In advance of digging into each chapter of Arrowhead Endurance, I've created a 39-page summary of how I design training plans.

What's in the summary?

"How to Design a Training Plan" details the following six key phases:

1. Determine the demands.
   Figure out what your goal event will entail. This is the framework to structure your training around.
2. Benchmark your baseline.
   Test yourself to find out where you're starting from.
3. Check yourself.
   BHAGs are fine for motivation, but bite-size goals are better for progress. Don't bite off more than you can chew (in one sitting).
4. Start at the extremes.
   Modern training starts at the extremes—of patience, planning, strength, speed, duration, and execution—and converges toward the demands of the goal event.
5. Bridge the gap.
   To get from the relevant extremes to goal readiness, it's necessary to use converging periodization—a methodical, progressive change in every workout.
6. Arrive and thrive.
   Athletes don't follow training plans. Training plans follow athletes. Learn how to make sensible adjustments when life doesn't cooperate.

Download the PDF.

To read the PDF, visit the Downloads page.

Last week, I tested three different equipment setups and their impact on uphill speed. The verdict? Every 1% removed from the feet increased uphill speed by 5%, with no speed penalty on the descent.

Here's the formula you need to make weight changes relevant to you:

Inspired by a Reddit post, I tested different-weight ski setups on the same terrain and conditions to measure the impact of weight on climb rate. To isolate weight as the only variable, I completed four laps at a controlled intensity:

1. with race gear;
2. with light touring;
3. with typical touring; and
4. again with race.

The Test

• To ensure precision, I used a chest strap heart rate monitor rather than an optical wrist sensor. A chest strap directly measures heart rate via electrical activity, while a wrist monitor does so indirectly, measuring blood flow;
• To ensure a repeatable intensity, I targeted my aerobic threshold rather than my anaerobic. Since the aerobic threshold can be maintained for hours, there's less chance of fatigue affecting the result;
• To compare different weights, I used three sets of ski equipment:
  • Race: 1,526 grams per side, including skins, skis, bindings, boots, and poles;
  • Light Touring: 2,602 grams per side; and
  • Typical Touring: 3,286 grams per side.
• To minimize errors, I did four laps rather than three. This served two purposes:
  • To test the RPE of the first lap: The first lap was a warm-up, so although my pace was constant, it took close to 15 minutes for my heart rate to reach my aerobic threshold.¹ Heart rate always lags intensity, so I used a steady pace and waited for my heart rate to catch up.² The fourth ascent was only 0.6% slower than the first—16:46 vs. 16:38—so I could confirm that my starting pace was correct.
  • To test if fatigue was a factor: Although the laps were short, I wanted to ensure that any increase in time was not due to fatigue and a slowing pace. By bookending the session with laps on the same equipment, I could compare the times and adjust if necessary. (However, with only a 0.6% time difference, an adjustment isn't required; the errors in GPS and VAM calculations are probably more significant.)

Equipment Weight

Here are the weights per component and the increases (in grams and percentages) compared to the Race equipment.

Compared to the Race equipment, Light Touring was 70.5% heavier, and Typical Touring was 115%.

Lap Times

Compared to the Race laps, Light Touring was 14.3% slower; Typical Touring, 20%.

Conclusions

Gear weight significantly affects uphill efficiency.

Adding just over a kilogram (per side) decreased the climb rate by 14% between the Race setup and Light Touring.

For the full impact, the total system weight must be compared.

It's misleading to consider only the equipment. The weight increase between Race and Light Touring was 70%. In isolation, that suggests a significant change is needed to affect the climb rate, but the actual tipping point is much lower.

In contrast, the increase in weight compared to the total system weight—gear plus clothing plus body weight—is proportionally slight. In this case, it was only 2.87%.

\(\text{Weight Increase} = \frac{77,204 - 75,052}{75,052} \times 100 = \frac{2,152}{75,052} \times 100 = 2.87\%\)

Every 1% increase in total system weight resulted in a 5% decrease in ascent speed.

Only when total body weight is included can we calculate the actual impact.

System weights for a 70 kg skier:

\(\text{Total System Weight} = \text{body weight} + \text{clothing} + \text{equipment}\)

\(\text{Total System Weight (Race)} = 70,000 + 2,000 + 2(1,526) = 75,052 \text{ g}\)

\(\text{Total System Weight (Light Touring)} = 70,000 + 2,000 + 2(2,602) = 77,204 \text{ g}\)

Percentage increase in weight:

\(\text{Weight Increase} = \frac{77,204 - 75,052}{75,052} \times 100 = \frac{2,152}{75,052} \times 100 = 2.87\%\)

Time penalty per 1% weight increase:

\(\frac{\text{Time Increase (\%)}}{\text{Weight Increase (\%)}} = \frac{14.3}{2.87} = 4.99\)

🤓 Math FTW!

Lighter equipment has a bigger impact on smaller people.

Increasing equipment weight by 1 kg is a 1% increase (and likely a 5% slowdown) for a 100 kg person. But for a 70 kg person, 1 kg is a 1.43% increase (likely a 7.1% slowdown).⁴

Transitions with Race gear are no contest.

Although the times were decent, considering the awkwardness of the equipment, the touring transitions were still three times slower.

Better skis don't make for faster descents.

I didn't descend at race pace, but at roughly the same feel. The top speeds of Race and Light Touring were pretty much the same—74.4 km/h versus 75.0—despite having much more confidence in the edge grip of the Light Touring setup.

What wasn't tested

Is there a minimum weight that triggers the slowdown?

It appears not. Weight increases as low as 100 grams have an effect.

How Much Do Heavy Shoes Slow You Down?

A study finds that adding even a few ounces affects race times.

Runner's Worldalex hutchinson

Does the location of the weight matter?

Yes. The general rule of thumb is that increased weight on the feet is equivalent to five times that on your back—similar to what I found with my quick-and-dirty test.

Study: Energy cost of backpacking in heavy boots,

How does duration change the effect?

I suspect longer durations make the slowdown worse. It's well-known that high-cadence, low-load movement patterns are more aerobic than low-cadence, high-load patterns.

Increased weight increases the muscular load, increasing the demand for fast-twitch muscle fiber. A fast-twitch muscle fiber is more glycolytic, burning carbohydrates faster.

A heavier load not only reduces speed but also decreases fuel efficiency.

If you consume more carbohydrates per unit of effort, your glycogen reserves will deplete faster. This will result in an earlier onset of fatigue and, in the worst case, bonking sooner.

Pounds make pain.

Ounces make pounds, and pounds make pain.

The inverse is also true: removing weight creates joy.

It felt horrible when I switched from Race to Light Touring and then worse again to Typical Touring. But from Typical Touring to Race, it was a thrill.

The opposite sentiment? "Go light, delight!"

1. To force a specific heart rate in too short a time is "wagging the dog". Because of heart rate lag, the initial speed would be too high, and heart rate would misrepresent the intensity. In this case, that extra speed would have overstated the importance of lightweight equipment.
2. When training, I always note my ventilation patterns relative to my heart rate. With that experience, I can maintain specific intensities by monitoring ventilation for different durations. For uphill hiking and skinning, breathing with a two-steps-in, two-steps-out rhythm for 15+ minutes will be about aerobic threshold. (In contrast, two-in, two-out at the start of a race is closer to anaerobic threshold because it can only be held for ~5 minutes.)
3. I had to interrupt these descents in the interest of skier-snowcat diplomacy. In between runs, a snowcat started work on part of my descent, so I had to slow down and detour. Interestingly, the top speed of the second Race run was still close to that of Light Touring.
4. Going alpine climbing? This demonstrates why evenly distributing weight between packs is inefficient—it slows smaller team members more than larger ones. For the highest team speed, pack weight should be scaled according to the person's weight. (My climbing partners who outweigh me by 50 pounds always balk at this idea...)

How to use "The 1% Rule"

The "sand" of endurance training is aerobic capacity, which primarily comes from high-volume, low-intensity training. Aerobic capacity is a long-term "more is better" component, but it eventually runs into lifestyle constraints.

The "water" is intensity, which has to be applied in the right amount at the right time. It's a Goldilocks component; you need it just right—not too much, not too little.

The necessary expertise to combine the sand and water comes from experience, good coaching, or both.

Basic endurance is dry sand.

Basic endurance is like piling perfectly dry sand. Without any moisture content, the grains won't stick together. The sand is always piled in a cone.

With only a cone of sand, the returns diminish as the pile gets higher. Each additional inch of height requires a greater volume of sand to cover the previous one. Eventually—due to genetics or life constraints—you can't add any more.

Intensity is water.

Adding intensity to a training program is like adding water to a pile of sand. With some moisture, you can start to shape the sand.

Shaping the sand allows for taller piles and interesting shapes. You aren't limited to dry cones. It lets you steepen and sculpt the pile and increase the height without needing as much volume.

Adding some intensity is exciting and gratifying because:

• You can shape and sculpt faster;
• You can make the pile steeper; and
• It gives the illusion of a shortcut—changes happen quickly.

If a little water is good, is a lot of water better?

With sandcastles, obviously not. But what's an obvious mistake with a sandcastle is, for most people, just a little too tempting in training.

With sandcastles, no one says:

It's falling over! Add more water!

or

If water is better than sand, let's just use water!

But self-defined intensity is also fun—true high-intensity is not—so the temptation in training is hard to see for what it is: an illusion.

Too much water is destructive, not productive. (...unless your selling short-term-focused exercise fads. Then, gratification via intensity is The Money.)

A Stronger, Smarter Approach

Basic endurance is the foundation. It must continually grow.

Intensity refines the structure, but it can't stand alone.

Great training is about balance, knowing when to add water and when to add more sand.

With a map in hand and hours of preview behind you, identify where you’ll perform best. Consider your background in other sports, the movement patterns you excel at, and your strengths—or limitations—relative to the field.

During a typical skimo race, racers suffer from panic-and-lactate-induced tunnel vision. Your focus narrows and your decision-making suffers. What you might notice with a resting heart rate becomes invisible at your anaerobic threshold—unless you've previewed the course and already know where to go.

To avoid losing your way:

With the best time for training long past, The Skimo Cheat Sheet is your best bet to get faster right now. You can download it below.

What is the Skimo Cheat Sheet?

The Skimo Cheat Sheet is a collection of 32 tips that will give you a faster race with a minimum of effort.

• Paradigms: Three ideas to embrace, 10 to avoid. (More on the latter later.)
• Training: Skip it. By February, it's too late to build any significant fitness.
• Technique: Four skills to practice.
• Tactics: Four strategies to improve performance.
• Tools: Seven ways to prep your gear.
• Tenets: Three principles of racing.

The Download

To get the cheat sheet, visit the Downloads page.

Next week, I'll have a full description of the importance of training pure speed and how to structure it. Here's the super short version:

Periodization

Maximum speed is primarily a capacity-building tool. Hand-in-hand with maximum strength and maximum (effective) duration, building capacity should come at the beginning of a macrocycle.

Venues

Most athletes can train maximum speed with their typical training venues, but mountain runners should avoid using a flat track for fear of injury. Instead, find a gradually steepening hill between 10 and 25%.

Protocol

The following protocol is adapted from Steve Magness' The Science of Running.¹ Frequency can be once a week alongside maximum strength or twice a week on its own.

Benefits

It's the top rung of the speed ladder on the way down to race pace.

Inspired by Renato Canova², my method uses converging periodization. Macrocycles should start by building capacity at the extremes (of speed, duration, strength, and execution) and work their way toward goal pace.

Although the saying "speed work makes the dream work" makes me throw up in my mouth, I can't deny the truth of the claim. Speed is important, even for mountain sports.

But how to train pure speed is not as well known as the cliched phrase.

The volume is super low.

Pure speed is a small reservoir. Once it's empty, banging on the drum doesn't get anything out of it but frustration. The total number of reps available is 5-10, maybe 15 with lots of experience.

Sprints are super short.

To hit the right intensity, each rep needs to be very short. Saying "30-second sprint" is a lot like "devout atheist" or "jumbo shrimp." The duration per rep is only 5 to 12 seconds.

Sprints are not maximal.

The effort needs to be near-maximal, not full-out. In the gap between near- and maximal is a calm mind and perfect execution. Stay relaxed, and maintain good form. Going all out will hinder both. Think 95%, not 100.

The rests are really long.

Much of the benefit comes from muscle fiber recruitment and stimulating the anaerobic system. To repeatedly hit the right intensity, rests must be 2-3 minutes and passive. Don't just do something; sit there!

In a future post, I'll detail the workout protocols and benefits of sprinting, according to Olbrecht, Canova, Magness, and Verkhoshansky.