Contact Strength, Max Recruitment, & Power Training

‘Contact Strength’, ‘Max Recruitment’ and ‘Power’ are terms used often by climbers in training, but their actual meanings and inter-relationships can be somewhat ambiguous.  As the first in a mult-part series on the subjuect, this post will attempt to clarify these terms and explain precisely what they mean for Performance Climbers. 

Skeletal muscle is composed of many individual muscle fibers, and they don’t always work in unison.

Each muscle in the body is composed of a multitude of individual muscle fibers.  When your muscle completes a contraction, not all of these muscle fibers are contributing to that contraction in a useful way.  Some fibers may contract at the wrong time, or too slowly to be effective, some may not contract at all.  Some of this is accidental, but some is intentional.  Individual fibers cannot sustain a contraction over a “long” period of time.  Any sustained muscular contraction is achieved by alternating the brief contractions of individual fibers (allowing some to rest while others are working).  This has obvious advantages to endurance athletes, but is problemmatic for those seeking to produce the greatest amount of force for a single, short burst of effort.

Max Recruitment Training is all about maximizing the amount and effectiveness of muscle fiber contractions for a single effort.  This is done in part by increasing the number of active fibers during a contraction.  The goal for climbers training Max R is to increase the ability to generate maximum force to execute one ridiculously hard move.  Of course, most of the time ‘ridiculously hard’ moves are atleast somewhat dynamic, which brings us to an oft used (and mis-used) term in performance climbing, “Contact Strength”. 

Contact Strength is a widely confusing term, so let me spell out my definition.  When you grasp a hold, your muscles do not exert peak force on the hold immediately. It takes “a while” (on the order of a tenth of a second in some human muscles*) for your muscles to generate maximum force. “Contact strength” is basically the amount of force you can generate during the period of initial contact with the hold.  This is critical to climbers executing a dyno, because you need that force to ramp up as quickly as possible, during the brief instant when your fingers are still in contact with the hold you are dynoing for. 

Contact Strength: if you can’t generate high force quickly, you won’t be able to ‘stick it’.

You’ve probably heard of “fast twitch” and “Slow twitch” muscle fibers, each designed to be more effective in different types of contractions.  Slow Twitch fibers are more dense with capillaries, allowing them to sustain areobic activites, but they take about three times as long to contract as “Fast Twitch” fibers.  On the flip side, Fast Twitch fibers are unable to sustain long efforts.  Fortunately for the “tortoise” climbers out there, some slow twitch fibers can be trained to behave more like fast twitch fibers (trained to contract more quickly).

A highly magnified cross cection of muscle tissue showing three muscle fiber types. Type 1 are “Slow Twitch” (the most common type), Type IIB or IIX are “Fast Twitch”. Type IIA fibers have attributes of both fast and slow twitch, and can be trained to behave somewhat like either.

However, true “max Recruitment” training in the weight-lifting sense doesn’t necessarily train the speed element of a contraction, but rather the maximum generation of force independent of time.  A weight lifter looking to max out his deadlift can tug and scream for half a second before the barbell actually lifts off the floor.  This can be true of hard climbing moves as well, as in the first hard move pulling off the ground or off a good stance, but in my experience the vast majority of crux moves must be executed dynamically.  So climbers need to find a way to train Max Recruitment that also helps to improve contact strength.  For this reason, it would probably be more correct to say that climbers can benefit from “Power Training” vice “Max Recruitment”, but since Power is a subset of Max R, both are relevant to climbers, its simply a matter of determining the best use of limit training opportunities.

Here are some general descriptions of a few climbing-specific activities that will help train Power or Max R in the climbing muscles without eschewing other key aspects of climbing training: 

Limit Bouldering: Pretty simple, bouldering right at your limit.  The key is to do problems that emphasize one or two REALLY hard moves, rather than problems that entail 6-8 pretty hard moves.  Remember, we want a small number of reps at very high intensity.  Bouldering at a lower intensity is fun and can have other training benefits, but to get Max R improvements, the moves need to be WAY HARD!  To get an additional power training effect, emphasize hard dynamic moves.

A good limit boulder problem will emphasize 1-2 really hard moves


  • Very sport specific
  • Trains entire body (finger strength and core)
  • Trains movement elements
  • Can be done outside
  • Way more fun & social than any of the other options!


  • Difficult to quantify intensity for purposes of tracking from season to season, can be alleviated with private wall or visiting outdoor boulder crags
  • Difficult to isolate specific muscle groups (may be limited by core strength, etc). Can be alleviated with routesetting privileges
  • Relatively uncontrolled, can lead to increased injury risk
  • More susceptable to external influences (peer pressure, projects at the whim of your gym’s routesetters, confusion between training & performance (desire to send training problem encourages unwise behavior))

Campus Training: This dynamic style of training involves footless dynos between like holds, and is probably the best method of pure power training available to climbers.  Look for some in-depth discussion on this in the coming weeks.


  • Easy to quantify
  • Easy to isolate finger strength
  • Best for improving dynamic accuracy & confidence
  • Perhaps the best method for improving “contact strength”


  • Higher than normal risk of aggravating elbows/shoulders
  • Depending on setup, can be difficult to progress
  • Not as specific to rock climbing as Limit Bouldering
  • Little movement training involved (although it does require some coordination, these movements aren’t very specific and not sufficiently varied)
  • Can be painful/hard on the skin
  • Requires special equipment (a campus board)

Hangboard Training: A hangboard can be used for any type of muscular training, its just a matter of varying the number and duration of reps and sets to achieve the desired goal.  Max R training on a hangboard would involve 2-3 sets of 1-3 reps of a short duration (5 seconds or less) for each grip position.


  • Easy to quantify
  • Easy to isolate finger strength
  • Can be done without access to crag or gym


  • Not very specific
  • Little to no dynamic component, which is key to Power Training/contact strength
  • No movement training benefits
  • Monotonous (after 4 weeks of Hypertrophy training on the hangboard, do you really want to do another few weeks of Max R on the hangboard?)

What’s my favorite?  I’ve never used a hangboard for Max R training, and I have no plans to, but I could see the benefits if you didn’t have access to a good campus board or bouldering facility.  Unfortunately the lack of a dynamic element is a significant disadvantage.  I think both Limit Bouldering and Campusing have their place, but I favor Limit Bouldering because of the benefits of training movement and the entire body system all at once.  In the next few posts I will go into much more detail on Campus training and how it should be integrated with Limit Bouldering into your training plan.


5 thoughts on “Contact Strength, Max Recruitment, & Power Training

  1. I like what you are doing here! Can’t wait to hear your thoughts in the next post… Also, I would love to see a post regarding your thoughts on periodization and how your system has evolved over the years.

    Keep it up


  2. Pingback: Campus Training Part 1: History, Theory & Campus Board Construction | Lazy H Climbing Club

  3. Any advice for setting problems for limit bouldering on a small home woody? Specifically, what angle do you prefer for the wall, small feet versus typical blobby indoor foot holds, best method for incresing the difficulty (i.e. increasing length between holds, worse holds/feet/body position)? This blog is great! Can’t wait to read your next post.


  4. I must thank you for the efforts you’ve put in writing this blog. I’m
    hoping to check out the same high-grade content from you later on as well.
    In fact, your creative writing abilities has encouraged me
    to get my own, personal website now 😉


  5. Pingback: Training for Climbing: Where to Start | GoodBETA

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