Edge Hangboard

I’ve just added the Edge hangboard to the shop. I’m excited to see this hangboard released which I’ve collaborated with Edgy Climbing Holds to design. I’ve used wooden fingerboards for 12 or 13 years and they propelled my standard in climbing beyond what I imagined they could (more on this below). So despite being on the face of it an extremely simple device, it is hard to overstate their importance in climbing training. I’d call fingerboards and fingerboarding the core exercise and equipment for strength in climbing. Something every climber ought to have in their home and use year round.

My first fingerboard was a single campus rung which cost me a few pounds. I used it to go from being stuck at around 8b/V10 for quite a few years to jumping forward to E11/9a/V14 in the space of about a year and a half. However, it wasn’t just any old piece of wood! The rounding and finish was just right for pain free comfortable training, and so I could do more on it and get stronger. Since then I’ve used some of the more popular models of wood fingerboard which are also pretty good. I’ve also visited some climbing walls with some fingerboard models which I feel are just nasty. Perhaps you can get away with lots of training on these for a while, but they just make my fingers hurt and as such end up being counterproductive in the long run. Obviously you can still make something great to train on by yourself if you have the skills. The problem is most people don’t do it and just want to buy one. So when asked to help design the Edge, I tried to think of the things I’d always wanted to make a fingerboard that is just right.

First, I wanted to avoid plunged pockets. I’ve seen some climbers do exactly what I tend to do and use poor form by ‘nestling’ fingers against the sides of the pockets for extra advantage. After a quarter of a century of climbing, my index finger joints have become permanently twisted. It could be just normal climbing that does this, I cannot be sure. However, I wanted to ensure my core training tool could not contribute to this. So I wanted a fingerboard to have an open rung to force the user to use good form.

Edge Hangboard from Dave MacLeod on Vimeo.

Second, I wanted three rung sizes, all with a carefully designed profile. I experimented with lots of profiles and settled on shapes that for me hit the right balance of depth, roundedness and finish and would most likely suit most folks strength levels. Some climbers have asked me about the rung depths which are 45mm, 21mm and 15mm, so that they might compare between other hangboards, but this does not tell you anything useful as the difficulty of hanging the rung is a function of not just the depth but the roundedness and texture/finish of the wood. I’m all for looking at numbers in training where they can be genuinely informative. However, in my view this is not one of those cases. Which brings me to simplicity.

My overriding goal with the Edge was to make the design simple. Removing unnecessary complexity to me is a highly desirable goal in all aspects of training, including the equipment. Simplicity re-focuses the athlete on the important things like level of effort, strict form, completion of the training and listening to the body. Additionally I’m acutely aware through coaching many climbers that the somewhat garish appearance of some fingerboards are an impediment to building fingerboarding into the regular routine of climbers with family/shared homes and busy schedules. A fingerboard that is conveniently situated is a lot more likely to get used, but some non-climbing relatives or friends legitimately object to a loud or ‘homemade’ looking training setup being installed in an otherwise nicely decorated kitchen or living room! So we wanted to make the appearance of the Edge as low-key and neutral as it could be without sacrificing any functionality. Climbers who live in a climbing household, or alone, might scoff at this idea, but I’m certain that a good number of climbers I’ve coached will welcome it and finally get their home fingerboard installed.

Finally, we wanted to make the hangboard from wood that is sustainably and locally sourced and manufactured. The hardwoods used to make fingerboards is a resource which can be a contributor to environmental damage along several lines (GHG emissions, transport, deforestation etc) and we didn’t want to be a contributor to this. We knew this would noticeably raise the cost compared to some other boards which sometimes use imported wood and/or manufacture in distant corners of the globe. Edge boards are made from Scottish Ash and each board carries the precise grid reference of the source tree. It also carries the Scottish Working Woods logo. As a licensee of this label scheme, it ensures that the wood and manufacturing is local, and the scheme is managed by a range of environmental organisations such as The Forestry Commission and Reforesting Scotland, which promote sustainable practice of both forest management in Scotland and production of wood products. Clearly, this is something that’s important to me, and my guess is that it will be important to lot of climbers, who as a group are more environmentally aware in general and supportive of efforts to minimise the impact of our activities on the environment.

So, with all that said, if you are thinking “that all sounds good, I would like one, but how do I use it” I took some time to make the 25 minute video with a good deal of information about most aspects of how to fingerboard. My view would be that what’s not in this video is less important, but if it leaves you with further questions, please leave a comment below and I’ll try to answer it, and if need be update the video. The video is aimed at folk who don’t yet habitually fingerboard, or do a bit and want to get more out of it. In due course I’ll make another one with some even more geeky details for real board monsters.

You can check it out and order here (shipping worldwide).

How to Hangboard from Dave MacLeod on Vimeo.

Reflections on beginning climbing coaching again

A few shots of my own training over the past few days

I built a large climbing wall at my house a year and a half ago, not just for myself, but with the intention of running climbing coaching sessions there. I knew it would be great to have a dedicated climbing facility that I’d set up myself, without some of the limitations of big climbing centres. Last week, as part of the Fort William Mountain Festival, I ran my first few classes - three hour masterclass sessions with groups of climbers travelling from as far as Belgium to join us.

I hadn't run clinics earlier as I spent some of last year recovering from surgery and then just wanted to go climbing! So it was really interesting to be assessing and observing climbers again after a break for a while and gave me a chance to reflect on what patterns these sessions reveal about climbers and what holds them back or propels them into improvement. Here are three themes that filled my mind after the sessions.

1. The ability to try hard still trumps everything

As usual I met some climbers with good technique, some with strong fingers and some with good tactical awareness. But out of all the climbers on my sessions, I met very few who had trained themselves in how to try hard. And so they were not improving nearly as fast as they could be, even when they had already made other good training decisions. You can design a great training programme, show up and complete every session and immerse yourself in climbing tactics, but if you don’t know how to really try, where is the stimulus to yield improvements from that training?

I think I was especially aware of this because we were in my own wall, where I normally train, uninhibited by anything. Some of the climbers I coached clearly had significantly stronger fingers than me, but I sensed that they did not habitually fight to the death on a routine basis.

To gain strength, the body really needs to be pushed into it, especially if you are not that young any more. In my mind, a big overarching weakness of many, if not most climbers is simply the ability to get really determined to get to that next hold and hold onto it. Often when you put this point to climbers, they are confused, even a little unhappy about the suggestion they could be trying harder. But think of this applied to other core skills of climbing - Of course it ‘feels’ like you are trying as hard as you can, just as easy routes feel at your limit when you are unfit or sequences are at the technical limit of climbers who are not immersed in climbing day in day out. This does not mean this limit is fixed. The ability to focus physical and mental energy is trainable just as other skills are. The limit is not fixed.

It is not just about delivering physical effort either. It is also the ability to make every single climbing session an immersion in deep concentration anticipating and then analysing each effort on each route, and comparing technical strategies for the moves with that of your climbing partners. Way too many climbers are resting their minds as well as their muscles in between efforts. 

If you start off by training your ability to focus and deliver a huge mental and physical effort during your climbing/training time, the rate of improvement rises. This helps to explain why two climbers who both climb the same number of routes per week at the same climbing wall improve at very different rates.

A final point on this - often I find that it doesn’t always work for me to make this point about trying harder. Climbers sometimes consider me, as a professional climber and coach, to be somehow ‘a different animal’ and not subject to quite the same constraints. However, the great thing about group coaching sessions on a bouldering wall is that over the course of the session, as we work on problems, me offering technical pointers of the fine details of the movement that get you closer to succeeding on each move, climbers in the group start to rub off on each other and lose their inhibitions to try harder than they otherwise would. They see the others doing so as desire to solve the boulder problem overtakes physical and mental inhibitions. They concentrate deeper and pull harder and often pull off some moves that seemed far off, an hour previously. Even if they don’t, I always hope that climbers can see this happening among the group and understand that real concentration and real grit is the basis for training that works.

Lesson? Boulder more, do it in groups of the keenest people you can find, and get into the habit of systematically offering each other feedback on moves and encouragement at every turn. Training is only training if you are really trying both physically and mentally.

2. Time remains a key currency of improvement

A big proportion of climbers are still seriously constrained by time to climb and train, and just as important, constrained time to rest and recover properly from the training they do get. Some only have time for one or two sessions per week. Others have time for four or five, but only get the results of two sessions, simply because they don’t have time to sleep, eat and rest well enough to get good results from their training.

I hope that running coaching sessions at my own wall would spark people’s imaginations about what fantastic training facilities you can make in a small space. My wall is about as badass as they come for home walls and it took a fair few years of prudent financial decisions to get there. But I remind folk that my last wall was in a small room and was still amazing, and the one before that was a single campus rung. The single campus rung got me up the world’s first E11 and from 8b to 9a in 18 months. 

When time is constrained, convenience is the king of training variables. Many of the climbers told me familiar stories of living just minutes from a big climbing centre, but how it was difficult to get themselves to it in the 90 minutes or so they had to spare after a tiring days work that hits you after you put the kids to bed. I have two responses to this problem. First, a home facility, no matter how small, removes the ‘getting myself out of the door’ barrier to completing the training. Second, remember that when you feel tired later in the evening, it’s because your body’s metabolism is slowing down. You can usually reverse this feeling after a ten minute warm-up and feel just fine again. Moreover, creating a late evening ‘second wind’ like this doesn’t necessarily interfere with your sleep. In fact, the physical activity and mental wellbeing that goes along with it can often improve it.

I noticed that the proportion of fingerboard-owing climbers seems to have risen since I started coaching ten years ago. However, the proportion of those actually using them has not risen nearly as much. This is a rather basic problem for which I offer some solutions in my book 9 out of 10 climbers. Underlying these is a principle that relying on using willpower to make yourself train if you don’t enjoy it tends to be unsuccessful for most. Instead, you change the environment or routine, to make it take willpower NOT to train instead. 

Putting your fingerboard in the highest use area of your house, so it’s where you always are, and highly visible is one way. Another is to use social pressure to your advantage. Ever noticed that your house is at it’s cleanest and tidiest when you have friends, or the landlord coming round to visit? You can capitalise on this social pressure in your training too. Invite your training partner round to share a fingerboard session two or three nights every week. You are less likely to skip it when you know they are coming. Got a TV programme or radio programme you never miss? Combine them with the fingerboard routine. It removes the boredom and makes it part of your week’s enjoyment. Digital tech these days makes this easier than ever.

There are countless other ways to tilt the behavioural environment to make it easier to complete your training, and harder to miss it. Use your imagination for your own routine, or get a coach to tell you straight.

3. Protect your hard earned gains better

It seems to me that the improvements in climbing walls could be widening the gap between the extremes of the bell curve of ability across climbers. Some of the climbers on my classes were in pretty poor physical shape, despite having a lot going for them in other aspects of the whole performance picture. Again, busy schedules are often the underlying theme responsible for this. But simply being aware of it can help you to mitigate it. A basic principle of training is reversibility. I discuss its implications in 9 out of 10 but I think it bears reinforcing as I still think climbers undervalue its effects.

Many climbers have lost periods of weeks or months of little or no training for a few common reasons - work/accommodation/family transitions, injury or simply focusing on something that makes you weak such as trad or alpine climbing. Now, some loss of base level strength and fitness may be unavoidable due to these things. But that doesn’t mean you should completely abandon any attempt to mitigate them. Yet that is exactly what many, if not most climbers do.

The result is that so much form is lost and it takes months to return to where you left off, if indeed you ever can. I have made this mistake myself several times. With hindsight I can see that 1 year without a board while I moved house and saved to construct my new board caused my level to drop to 8c. I was still out climbing just as much, but I just didn’t train. And so I lost strength, capacity to handle training and agility. Only now do I feel like I’m getting it back, 18 months later. Similarly, while recovering from surgery last year, although I trained harder than ever and emerged with stronger fingers after three months off my feet, I still lost some agility and base level of fitness. I could have mitigated much of this by incorporating more basic body strength and fitness exercises into my routine. You don’t need to make the same mistakes as me.

Of course, this problem doesn’t always apply - keep in mind your individual weaknesses. Wall rats who can be found in the climbing wall training hard 5 nights a week are often pretty strong and fit, but their climbing ability on rock will never match this because they lack the hard-to-measure tactical skills of being a rock climber. So far weaker souls who get to the crag more often will still out climb them.

Lesson? Life throws up things that interrupt your training. If you don’t plan for this, you’ll lose out. The time to really organise your training is not so much when you have lots of time, but when you have less. Don’t make the mistake of doing nothing, when you can only do a little. If you do, you’ll spend all the ‘good times’ just catching up to where you were, rather than breaking new ground.

So there are some highlights of themes I noticed that applied to a good swathe of the climbers who visited my wall for coaching. Of course there were many more - frighteningly common footwork errors, training errors, poor diet choices, psychological approaches and many more. If you are reading this thinking you’d like to get some coaching yourself, stay tuned to this blog as I’ll post up some dates I’ll be running more classes during the year shortly.

A few Beastmaker tips

At some point I’m still planning to write a small manual on the gory details of physical training for climbing for those who’ve already got all the ‘top level’ stuff sorted from 9/10. However, in response to popular demand since we put the Beastmakers in the shop, here are a few important points about using your fingerboard:

1. It's a supplement, not a hiding place. Finger strength is such a key ingredient of climbing hard grades. Yet whenever I write advice telling people to get and use a fingerboard, I make a little cringe. This is because I have seen so often the problems it causes which cancel out the finger strength gains. As Beastmaker designer Dan Varian himself says, the world is full of strong folk who hang out on their Beastmaker every night, can perform eye watering numbers of one-armers on hardly any fingers. Yet they still can’t climb hard. Well, relative to their strength anyway. 

I can’t even do some of the hangs considered Font 7b on the Beastmaker, and my top indoor grade is Font 7c+ish yet have climbed Font 8b+ on rock. Since I’m a rock climber, that’s the way round I like it! Lots of strong youths do it the other way round. If you want to be good at pull ups, that’s fine. But most of us want to climb hard on rock.

Sometimes the over-reliance on fingerboarding as a training Panacea comes from simply not realising how important technique is (see this post for more detail). Sometimes the fingerboard becomes a comfort blanket - the only place you know you can perform well and consistently. If you are stronger than your mates but they still burn you off on Font 8a outdoors you think “I’ll go back to the Beastmaker”. Your hiding place. Hiding from the really hard training - learning to climb harder moves using less strength and getting more weight on your feet. As soon as you begin acting this out, you are no longer training, but just going through the motions. 

The solution is to keep the real rock/basic training ratio high. Many of you will be watching the Olympics right now. Imagine if the gymnasts spent their time just lifting weights and not practising their routines. Could they win? Imagine if they only practiced their routines and never performed them in a competition setting. Could they deal with the pressures of the comp day and win?

Adding basic finger strength training is always a good idea, but only if the technique training is increased too. 

2. Short frequent sessions are good. And they fit better into a busy life. Don’t skimp on your warm-up though. Develop a sense of when your fingers are warmed up and ready to pull hard. It’s not rocket science. If you are a new to fingerboarding, just be gentle and gradually experiment each session with what feels good. Once you are warmed up, working through all the different grip types constiutes your workout. The Beastmakers have a good App on the way to follow if you don’t want to use your imagination and plan your own workout.

The general plan is to train in a way that causes you to have fairly equal strength on all grip types. One of the great things about the renewed popularity of fingerboarding in the past few years has been that more folk have realised that openhanded strength is important. Often if you’ve never fingerboarded, your openhanded strength is so bad you can’t even understand how you could hold on with that grip. It’s not weird, you are just weak on it!

3. Be careful, very careful. Everyone get’s injured fingers and various other upper body tendons from climbing training. Your injuries will hold you back far more than tweaking your workouts will propel your climbing forward. So give plenty of attention to injury prevention. The weaknesses you start with and the length of your fingers relative to each other will dictate what will feel ‘tweaky’. If it means you can’t do something that your mate can, you’ll have to go with that in the short term. 

A good example of this is doing one arm hangs with a full crimp grip. Contrary to hanging with two arms, when you hang on one arm, your wrist is held at an offset angle and the force is distributed differently through your wrist and fingers. If you aren’t used to it or weak on it, it’s very easy to get injured. So just progress very slowly. Start your progression from where you actually are, no matter how weak that is. Use plenty of support from the other hand or a chair on the ground. If you don’t try and do hangs which are too hard for you, you can progress slowly and steadily and in the months to come you’ll be able to do those hangs.

Some more safety warnings:

- Don’t hang with a straight, relaxed arm. ‘Engage’ your shoulder and arm muscles so the weight of your body is not hanging through the joint ligaments. Holding a slight elbow bend is the best way.

- Deep locks are very hard on the elbows and a good way to eventually cause the onset of dreaded epicondylitis. Proceed with caution if you have healthy elbows and avoid the last few degrees of lock if you have bad elbows.

- Training when tired or distracted is the fastest recipe for an injury. If you’re always tired and have a lot on your mind, at least have a coffee and take a few minutes to focus yourself before your workout. Treat it the same way as driving in busy traffic - it’s dangerous, so if your mind is not clear to pay attention, bad things are going to happen.

4. Vary the workouts. Do a session of testing your strengths and weaknesses on different grip types at the start and then every few weeks. Then you’ll know what your weaknesses are. Right now my ‘thumb on’ full crimp and 4-finger openhand is weak (because my little finger is weak and my pronator can’t control the rotation during a one arm hang). So you can spend the next few weeks doing more hangs on these grips to strengthen them, while maintaining the other grip types with fewer hangs. What grip types you want to focus on might also be dictated by what projects you have too and that’s fine, in the short and medium term anyway. 

5. How much volume? There is a lot of conflicting advice about how many sessions per week is a good number. Certainly with the minimums it’s easy to say that one session per week will create only a small increase in strength from baseline which will level off. 2 sessions per week is also not that much to keep getting gains beyond the initial weeks. The debate starts when we talk about whether 3 of more sessions per week is optimum.

I don’t believe there is a correct answer to this because there are too many variables in the mix. Firstly, one man’s idea of a hard session is different from the next man. Some folk are great at really generating a maximal effort and creating a muscular stimulus from the session that actually justifies a rest day. Others need coaching to realise what a maximal muscular effort is. These folks could fingerboard every day with no problems.

Secondly, it depends on how much real climbing you are doing. If you’re doing a couple of wall sessions on routes a week and have a fingerboard at home you could be using of an evening, you could probably use it for 30 minutes (post warm-up) daily. But if you are doing three hard bouldering sessions a week and working on outdoor projects on weekends then 3 fingerboard sessions might even be a struggle to fit in without creating recovery problems. 

The only reasonable answer is to do as much as your body can recover from at any given time. Here are two examples from my own history:

Before the days when I had a home board, I used to fingerboard 5 or 6 days a week during the summer. My real climbing would consist mainly of outdoor tradding which is less intense and I had no problem integrating the fingerboard sessions. In winter when I was bouldering 3 or 4 times a week I’d only do 2 or three fingerboard sessions and sometimes drop it altogether if I was really bouldering hard on projects.

These days, I have a board and lots of bouldering close to home. Most of the time I’ll do 3 sessions per week fingerboarding. In the Lochaber monsoon when it rains every day from October to February I’ll up that to 4-6 sessions a week at the start of my board sessions. But some of those fingerboard sessions will be just a few hangs before I get into the boulder session and I have 18 years of training behind me to absorb this level of work.

It comes down to listening to your body. Start developing an ‘ear’ for your general and specific recovery state.

6. Get motivators. Fingerboarding is not an exciting pastime. Get good training partners, good music, good TV etc and don’t hang the fingerboard somewhere that’s going to feel like a prison cell. Don’t be one of the countless people I’ve coached who tell me “I’ve had a fingerboard up for a year but used it once”.

If the entire concept of doing something as dull as deadhangs seems like a struggle but you still want to give it a go for the sake of the climbing gains, make sure you give it a good go. The strength gains you get and the ‘opiate effect’ of a good workout takes time to tap into but are probably the strongest motivators. Loads of people hang a board, do two or three sessions then give up. If you discipline yourself to do it for a solid month without fail, hopefully you’ll start to get the nice feelings of having done some real training, and got suitably addicted to the small but noticeable gains to keep going.

But the first thing of course, get a fingerboard and get it up in your house.

Beastmakers in the shop

Since this site is one of the main places on the web to get information about training for climbing and our shop sells all the best books on the matter, it was about time we started selling some of the best training equipment too. So priority number one was to get hold of the best fingerboards on the market right now; the Beastmakers.

Designed by Font 8b+ boulderers and made out of rather lovely skin friendly wood, their design is clearly a labour of love and that is why they have become so popular in the UK. Oh, and they make your fingers strong. Well, owning one isn’t enough on it’s own. It’s the numbers of hangs clocked up that get makes the jumps in grades we all want. But having a well designed and skin friendly hangboard is a good first step.

I started fingerboarding in summer 2005 just after I first tried Rhapsody. At the time I was climbing F8b and the odd 8b+ and about 8A on boulders. After a solid summer doing my deadhangs most days I got back on the sport climbs in the autumn and was blown away to discover I could now climb 8c. The following year I did Rhapsody and the year after that my first 9a.

That raw finger strength was obviously the ingredient that propelled me forward to grades I never thought I’d get to. There are of course many young strong lads I’ve seen and coached in walls up and down the UK who would wipe the floor with me on a hangboard yet can’t climb nearly as hard outside, since power is nothing without technique. And technique is just as hard won as finger strength.

So every climber needs to have a balance between learning technique and learning to pull hard. However, every climber who spends any time training or aspiring to harder grades should have and use a fingerboard. And if they are going to own any one, a Beastmaker is a pretty good choice. 

We are stocking both the 1000 and 2000 models. The 1000 is designed with those new to training in mind (Font 5-7C) and the 2000 is a better choice for those already used to bouldering walls and basic strength equipment (7C-8C). They cost £75 with our normal £1.50 shipping. Shipping to Europe and the rest of the world are at normal Royal Mail rates.

Get hanging and get strong. The 1000 is here and the 2000 is here.

The Milo of Croton school of training with Freida MacLeod. I wonder how long I can still manage this?

Freida getting started with some assisted hangs

Measuring gains

My last post and comments from them reminded me of a significant problem in training for climbing, or anything where you train component skills/strengths away from the competitive arena of the sport - measurement of gains. 

KT was just commenting noting good gains from training anaerobic endurance on a fingerboard - great! In my head my immediate question was - where was the gain measured? On the fingerboard? Or in the ‘real’ climbing? It made me realise that the significance of this question might not be immediately apparent.

If you train on a fingerboard for climbing, then gains measured on the fingerboard (personal bests on the exercises) give useful information that the training is working or not. However, if gains are happening on the fingerboard but not the ‘real’ climbing, then there is information about whether it’s been the right kind of training.

Naturally, It’s necessary to obsessively monitor both, and any other measure you can get your hands on. Measuring changes in performance variables in as many different situations as possible allows you to make many deductions and useful monitors about the effectiveness of the training choices and how well you are adapting to it.

Some important points linked to this:

The ultimate measure of training effectiveness is the final climbing performance, and this measures both the adaptation of the component skill being trained, and also how much it’s contributing overall. For example if you put a lot of time into improving raw finger strength on a fingerboard over a year or two, but climbing ability actually goes backwards (quite common) then maybe the time taken to achieve the strength gain has caused losses in far more influential areas. Maybe there is some information in there about your real weaknesses.

That said it’s easy to underestimate the value of basic strength or endurance gains from a basic strength exercise because it takes time to work it’s way into your climbing technique. In my book I discussed this effect - The body needs to ‘learn’ that it has the new strength and this only happens when you leave the hangboard and go back to performing for an extended period. An extended period means anything from a month to a year or more.

While you measure gains in one area, remember the ones you are neglecting are going backwards, not staying still. Take this into account when measuring effects in overall climbing performance. Similarly, if your training is improving several separate areas at once, as is normal, don’t be too quick to attribute gains to one possible cause, when it could be the other(s).

The common tendency is for sports people to only measure one or two components of their game - the ones they like training the most, and put all gains or losses in ability down to these.

- Climbers who use campus boards a lot tend to know their personal bests on a given board very well, even if they are climbing well but haven’t been campusing they go back on the board and when unable to touch a previous PB, feel they must have got weaker and their good climbing form must be down to other factors like technique etc. Not necessarily.  The specificity of basic strength exercises is not to be underestimated, and strength measured on one piece of apparatus is only truly a measure of strength on that apparatus, not strength generally.

Fingerboarding -timings

Several climbers have picked up on routines floating about the web advocating very short rest periods between sets on the fingerboard - like 6-10 seconds hanging with 3 seconds rest. They have compared it to notes in my book talking about 5-8 second hangs with more like a minute’s rest. Confused?

The regimens are very different because they are training completely different things. The former is an anaerobic endurance protocol. It replicates roughly what happens when climbing a route - hanging for some seconds on each move with only a few seconds rest as the hand reaches for the next hold. The rationale for using a fingerboard to do this type of endurance training is two-fold:

Because you can’t get to a real route or bouldering circuit to do this training more effectively. Or…

You already train a ton and need something that bit more intense to keep the body responsive.

Clearly both are a very specific and fairly rare set of circumstances. Most people can get to some real climbing, and they should do that instead because they need the technique element of the training every bit as much as the fitness. And very few are doing enough training to have squeezed everything out of the technique element and need a really intense stimulus to keep the body responding. If you do fit those above special cases, using the fingerboard in this way could be useful as a very intense way to build anaerobic endurance.

The majority of fingerboarders are doing it to gain strength. Gaining strength needs a high force stimulus - pulling at your maximum. If the rests are short, it’s not possible to sustain this - you get pumped and can’t pull your hardest. So that’s why you rest fully between sets and the sets are 90% plus of your maximum force.