By Steve Bechtel

Endurance is the ability to display power or strength over time. It can be of continuous, high intensity, or it can be intermittent in nature. There are many different ways that endurance shows up in our sport, and there are a few key lessons to take home before we start equating simply working up a sweat with being able to beat the pump.

  1. Endurance needs to be understood in terms of specific needs. Overall “good endurance” across the board doesn’t exist, and it should not be pursued. Endurance is extremely specific, so we should start our endurance journey by using the information our bodies provide. If I pump out on juggy steep walls, spending time there might be more useful than in a spinning class.
  2. Endurance is “expensive” to build and maintain and can compete with our power, our strength, or simply our ability to recover. There is no maximizing all of these abilities at once, so it’s important not to pursue that goal.
  3. We should be aware that there are two big dimensions to endurance that most people ignore. These are capacity and power. Power gets confusing because it’s the same word we use for explosiveness, but in this case, we need to think about output. Capacity is being able to handle a given volume of work, i.e. being able to climb 45 boulder problems in one hour. Power (anaerobic or aerobic) is a measure of how intense an effort you can sustain for a given duration. Capacity allows you to replenish energy stores quickly, power lets you use them effectively.
  4. General capacity training, what we might call “getting some exercise,” is generally more useful than non-climbing high-intensity endurance training, such as sprint intervals with the legs or using the SkiErg. Intense endurance training takes a lot of energy, and (as per point 1 above) should be specific.
  5. All endurance training is actually speed or power training. We’re not really just looking at going forever and ever, we’re trying to go as fast as possible (El Cap speed record), or being able to do slightly harder moves over the same time / distance (trying to do the 13a adjacent to the 12d we just sent). This helps us remember that just going to the end of our possible stamina is not really all that useful for rock climbers and boulderers.
  6. Most of us need better “cardio,” but not for performance in climbing. It’s mostly about general fitness and avoiding dying of cardiorespiratory disease. Interestingly, many athletes that require high levels of muscular endurance, such as short-distance speed skaters, show only small increases in VO2 Max (5-10%) with high levels of training, but show massive increases in local blood supply (50-250%). In some cases, improved endurance performance is associated with decreases in VO2 (Stenin, 1973; Zatsiorsky, 1974; Zima, 1975; Melenberg, 1981).


I routinely find myself confused by all the big words in studies and textbooks, and it’s reflected in my hard-earned 2.43 GPA, which I received from the only 4-year college in the least-populous state in the US. I tell people that my friend Tom Rangitsch and I went to college for the same number of years, only he turned out to be an MD, and, well, I work at a gym. 

I've been studying sport performance for more than 30 years, and I still get confused by the words and ideas that I see from experts. What I am writing today is an article on how to understand these ideas without getting lost in a sea of big words. I am as guilty as anyone of using too much terminology and not enough common sense, so maybe this is me trying to fix that. Maybe it’s easier to write at an eighth-grade level if that’s where you stopped learning…

Endurance, as I wrote earlier, is the ability to keep doing a task over and over. We can look at a simple exercise such as a pull-up to illustrate this. Getting from the point of not being able to do a pull-up at all to where you can do a proper pull-up is reliant on a part of fitness called strength, which is our body's ability to create force. It's doing hard things for a short time. Getting to where you can do multiple pull-ups is where endurance comes in.

When we are trying to make our bodies better at this part of fitness, we can have several different goals. We could want to do several pull-ups in a row. We could want to do a set high number of pull-ups, such as twenty, with additional weight added to our bodies with a weight belt. We could want to be able to do lots of pull-ups within the timeframe of a day, but not all in one group. We could even want the ability to do pull-ups several days in a row.

The amazing thing is that we can train and get our bodies to do any of these things. The workouts we would do might even help us get better at more than one of these goals at the same time. Some people have enough natural endurance that they could even get better at all of these things. The mistake that most of us make is thinking that all the parts of endurance are the same. It's sad, but working on getting better at one part of endurance can even make a different part of endurance harder.

Our bodies move by sending energy to the muscles, sort of like a car's engine using gas to make it run. And like a car, our bodies have a few different levels where we can produce energy. It's not exactly the same, but you can imagine the gears in a car. When you start out from a stoplight, and are accelerating from not moving at all to your driving speed, it takes a lot of power, and it needs to be delivered fast. You use first gear for the first few seconds because it is very powerful. The problem is that first gear is only good for the first few seconds, and the car can't just keep going at that high power rate, so you switch to second.

Our bodies' energy systems are sort of like the gears in a car. We can use the first system for a few seconds before we need to switch to the next one. System 1 relies on the energy already stored in our muscles, and can be used for high speed or high strength if necessary. It's the system we'd use for our first pull-up, and then for a couple more before having to switch to System 2's energy. What makes it hard is that System 2 doesn't deliver that same amount of energy, so you might not be able to do pull-ups with that system until you train it up.

System 2 is like second gear in a car. It's not so good for starting out from a stop, but it can be used for longer than System 1. In humans, this system supplies most of the energy for a minute or so of activity before switching to System 3. If we think about climbing, lots of what we do is in this system.

System 3 is where we start to cruise. This one is a very-low power system, but it can produce energy for a long time. In fact, this is the system we are most reliant on for daily activity, for giving us energy during sleep, and for things like walking and easy bike riding. 

A good illustration of System 3 is the level at which you could climb comfortably, with no fear of pumping out. All of us have this “easy” grade somewhere in our minds. It’s not stressful to start up the pitch, you can talk with your partner, and you can easily recover if you end up doing a strenuous move here or there. This grade will be firmly in the aerobic intensity zone for you, and one of the primary goals for your climbing should be to see this grade level increase.

Each of these systems contributes energy to movement and just living at all times, and then your body tends to rely on the “best” one for a particular activity depending on how long it takes and how hard the activity is.

Not that you need to know this, but these systems have names that attempt to describe them. We'll keep using our terminology—Systems 1, 2, and 3—but here are the scientific names:

System 1: The Anaerobic Alactic, Creatine Phosphate, or ATP-CP system

System 2: The Anaerobic Lactic or Glycolytic system

System 3: The Aerobic or Oxidative system

Now, back to how we use these systems. We sometimes look at endurance as providing the energy for one effort, such as a single rock climb or a 5k run. In these single efforts, we want to give the perfect amount of effort, which often ends up being as close to our hardest as we can go. Going super slow in a 5k is something most of us can do. Going fast is where we get to see what we are capable of.

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To go as hard as we can for a given time is dependent on System Power, the amount of energy we can produce and use for one effort. This might be how much weight you can lift in one set of exercise, how fast you can run one lap of the track, or how hard a climb you can do for one pitch. Each one of the energy systems has a Power limit, and each one can be improved through training. (Remember: this kind of power is not explosiveness, but “output.”)

If we were to use our car example, the Power of a system would be the horsepower of our motor. A big motor would let us race off the starting line, and might have a high top speed. But there is also how far you can go in a car, right? How long you can hold top speed before the engine blows? How much gas is in the tank? When it comes to the body, this is called System Capacity.

Now we are getting into some complex stuff. Just remember that our car has three gears that we switch between depending on how hard the driving is. If we are going fast or carrying a heavy load in the car, we use System 1. Longer trips on the highway would use System 3. And remember that we can build a more powerful engine (System Power), or we can put in a bigger gas tank (System Capacity). 

I like to think of our energy system's Power and Capacity in terms of a box divided into four squares. In reality, each gear of our car has its own power and capacity, but System 1 has so little potential for capacity that it is hard to improve. Its System Power is best viewed as the power we all think of when we hear that word—our ability to sprint, jump, or do things explosively.

For our purposes, we'll smoosh both System 1 and System 2 in the "anaerobic" box together. Thus:

  1. So this is a lot. Let's talk about how we show our endurance in a given activity to make this more clear. An easy way for climbers to understand is to look at endurance in terms of one boulder problem.

Advancing a boulder.

The simplest way to look at building endurance is to look at a small unit of climbing. In our case, a boulder problem. We all know that there is a lot that goes into climbing a problem, such as reading the moves, friction, body positioning, momentum, and more. In this example, we'll only be looking at power output, or the energy we use to make movement happen. There are basically 4 things we can do to change what kind of training effect we can get from a problem.

If our session started with just one climb, we could opt for any of the four ways to progress that follow:

1. We could do more problems. If you've done much bouldering, you'll remember that you get tired toward the end of the session. Being able to do more problems in a session is what we'd call Capacity. We move from being able to do 20 problems in a session to being able to do 25, and that gives us the opportunity to have more fun, and progress our skills by giving us more chances to practice. Greater capacity eventually means more good tries per day at the crag, too. The way we build capacity is to keep trying to simply do more climbing, or hiking, or whatever, at an easy level and concentrate on moves or minutes or pitches without worrying about how hard the climbing is. The main goal is just more.


2. We can add more moves to a problem. Assuming the moves are about the same difficulty along the whole problem, we could go from doing, say, ten move problems to trying 12 move problems. Climbers often call this quality power endurance, but in our terms we'll call this quality Aerobic Power. This gets pretty hard to train, but the way we do it is simply to try to do more efforts or reps at the same level of intensity. 

Remembering the capacity idea above, we would allow for easier moves or exercises to improve that quality. With Aerobic Power, we really need to keep things the same difficulty. My favorite example is pull-ups. I am doing the same move over and over at bodyweight. As I go from 10 to 12 to 15 reps, it requires more and more system power (both aerobic and anaerobic), but doesn't require more strength nor more capacity. This is because my bodyweight doesn't change (no need for strength) and I'm just focused on this one set (no need for capacity).


3. We can do harder moves. This one doesn't directly affect endurance, but it is a key to being able to do more hard climbs, right? It's understood that being able to do harder moves requires you to work less hard on sub-maximal ones. For example, if you go from being able to climb V4 moves first try to being able to climb V8 moves first try, V4 will feel pretty easy and you won't be working as hard to stay on the wall. This indirectly increases your endurance. You can relax on moves at this level. Energy-wise, this is a way to increase Anaerobic Power, which is our first gear: creating more energy for hard physical moves for just a few seconds. Over our career though, this is the singlemost important factor in changing the grades we can climb.


4. We can decrease rest between boulder problems. Energy-wise, this increases our Anaerobic Capacity. This is our ability to switch on and off between medium-hard efforts, and is best seen in how you might feel doing one boulder per minute for 20-30 minutes. We can also do things like 4 boulders in a row with no rest, then rest 5 minutes, and then do the same again. These are hard workouts, and can increase our short route or long boulder endurance quite a bit. The problem is that they are hard to recover from and the fitness doesn't last as long as we'd like.

When we look to be able to endure more, we can do it best in one of two ways:

  1. We can focus really hard on building our capacities for 6-8 weeks.
  2. We can focus on building our powers for 3-4 weeks.

There are all kinds of various training programs for building endurance, but I think the most important step is simply committing to the process of endurance training, and then following through. One workout is a trauma. Eight of them done progressively is training.

Keeping yourself focused on one aspect of it is helpful, and you'll see way more progress that way.

The Energy Equation

It is useful to remember that more goes into training endurance than just working out and making the muscles better at their jobs. In truth, endurance is just power output over time. A lot goes into improving that, including increasing your skills and technical abilities, improving your movement quality, better motor control, better autonomic function, and, of course our energy systems. 

A huge lightbulb went off for me when I learned that we could improve our endurance both by improving energy production and by mitigating energy expenditure. I can eat better, train better, and improve the quality of my individual muscles, all in an effort to improve energy production. But for many of us, available energy is not even the limiter! We might have great production, but our ability to use it efficiently could be bad. To be more efficient (think being “thrifty” with your money), we have to continually work on better movement capacity, improving skills, and honing our mental game. Training is only part of the equation.

Putting It In Practice

Now we will look at specific workouts for endurance and how often to do them. Some of these are not easy to do on a home wall or your gym might not have all the tools I mention, so when you try to build your own sessions, keep the duration and difficulty of the exercises in mind. If you are creative, you can train almost any facet of fitness in almost any facility.

Aerobic Capacity Training

Remember, this is easy and continuous climbing. Our coaching team refer to this group of exercises as “extensive endurance,” and the way we advance is usually by doing more work at a fixed level of difficulty. You get this fitness mostly by climbing routes. Some people go for long traverses or treadwall laps, but I feel like most people benefit from just doing pitches and aiming to do more of them.

Toproping with a partner is fun and effective, and can be as easy as I-go-you-go, and trying to do more climbing each workout for several weeks. Eventually, you get to the point that more pitches aren't logistically possible, and other methods need to be considered.


Aerobic Power Training

These terms are confusing. Refer back to the 4 boxes above to keep things straight. This is really what most of us are talking about when we talk about “power endurance,” it’s our ability to sustain relatively powerful efforts under fatigue. 

These workouts are hard, and deliver an immediate feeling of, “I’m endurance training.” Unfortunately, the workouts are really taxing to sustain over long periods and interfere with other training adaptations. We want to do these sessions only for short periods—maybe 2-3 times per week for 3 weeks—before switching to less intense endurance workouts.

The workouts we do here should have really intense sets, such as 4 boulder problems done back-to-back, with long rests between so that our next efforts can be done at the same intensity. The goal is to become better at managing these efforts over the course of the 3-4 weeks, not to get totally fatigued on day one.


Anaerobic Capacity Training

These workouts can be really good for climbers, and most of us don’t ever train in this zone. In developing anaerobic capacity, we want to do very short sets (I like 12 seconds or less), with rests that allow us to work well for the next exercise. We can do several exercises in a series, such as:

3 pull-ups (rest 20-30 seconds, then:)

10 second edge hang (rest 20-30 seconds, then:)

5 box jumps (rest 20-30 seconds, then:)

5 inverted rows (rest 20-30 seconds, then:)

10 second edge hang (rest 20-30 seconds, then:)

Rest 3 minutes and repeat. 

This is best advanced by adding more sets and rounds to the circuit, and not by doing something to make the exercises themselves harder, like adding weight or shortening rests.


Anaerobic Power Training

Anaerobic power is just plain hard. You work for 5-15 seconds, rest an equal amount of time, and repeat that for four or five sets. This is 1-2 minutes at the limit you can climb. We do short boulders of 2-5 moves, or break up a circuit into sections, much like a project climb. You then rest a long time (8-10 minutes) and do it again. 

This is hard and requires discipline, like eating vegetables, or reading a book rather than eating ice cream and looking at your phone. It pays off big time, though.


No matter what you choose, you should always plan on your endurance work as a series of sessions rather than one hard session today. This means planning out 5-7 sessions in advance, perhaps 2 sessions each week. Consider how you are going to make each workout harder with respect to the factors listed above, and then try and plan to do just a bit more each time.

Progressions are tough to get the hang of. Too often, we build out a whole month’s worth of training on a spreadsheet, and then get really frustrated when our bodies can’t keep up or our schedules don’t allow for the time we’d planned. 

I try not to get too worked up if I can’t get the sessions all in on the days I planned. The critical aspect is staying with an endurance work long enough for it to change your body. Let’s look at a couple of progressions.

Anaerobic Capacity, 8 session progression

1-2x per week. A “series” is a group of 4-6 exercises.

Number of SeriesNumber of SetsNumber of ExercisesRest Between ExercisesRest Between SetsRest Between Series


Aerobic Capacity, 8 session progression, Route 4x4s

2-3x per week. 

Number of SeriesNumber of Routes per SeriesRest Between PitchesRoute DifficultyRest Between Series
33As neededEasiest available1:1 or about 8 minutes
43As neededAt least 5 grades below flash grade1:1 or about 8 minutes
44Lower off onlyAt least 5 grades below flash grade1:1 or about 8 minutes
44Lower off onlyIncrease one series by one grade if all routes were completed last time1:1 or about 8 minutes
44Lower off onlyIncrease one series by one grade if all routes were completed last time1:1 or about 8 minutes
44Lower off onlyIncrease one series by one grade if all routes were completed last time1:1 or about 8 minutes
44Lower off onlyIncrease one series by one grade if all routes were completed last time1:1 or about 8 minutes
44Lower off onlyIncrease one series by one grade if all routes were completed last time1:1 or about 8 minutes


One of our most successful plans for building big endurance has been the 8-8-8 Plan. The 8-8-8 Plan is a 12 week program aimed at making a long-term improvement in endurance capability. So often people go looking for a plan that will get them “in shape” for endurance, but only ever realize an endurance peak that takes them back to the same level that they previously attained. Imagine building the capability of not ever being fatigued on those previously hard routes. Imagine having not just one, but rather three or four good attempts in a day.

This program is broken into three 4-week sections. The first 8 weeks are dedicated to building your capacity for endurance, effectively training you to avoid getting fatigued while climbing. The final four weeks will more resemble the training most of us know in endurance work, and serve as training your body to handle massively fatiguing climbing while maintaining good movement and efficiency. 

One of the fundamental tenets of endurance training is that the ability sticks around a lot longer if the fitness is built over time. You can’t expect much to happen within the framework of just a few short workouts. This is reflected in one of the fundamental flaws of “fitness training,” which is built around seeking out the maximum fatigue possible as quickly as possible. When our goal is to continually be able to address highly technical climbing in a state of increasing fatigue, and maybe hoping to do it several times a day, doing 4 minutes of 20 seconds work and 10 seconds rest will provide little help.


Steve is the founder of Climb Strong, and is proud to be the worst coach on the Climb Strong team. A climber for more than 35 years, he has traveled to globe bouldering, sport climbing, and doing first ascents of some of the world's biggest walls. 

He is happy when asked, "do you climb trad?" To which he replies, "I've never had much use for it.

He is cofounder of the Performance Climbing Coach organization, and is the author of several books on training for climbing. He lives in Lander, Wyoming, with his wife Ellen, and children Sam and Anabel.



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