Margo Hayes showing some mean compression. Photo: Jennie Jariel
I’m indebted to Jared Vagy DPT “The Climbing Doctor” for his review.
It should be noted that the articles cited are from journals with both different impact factors, as well as different sample sizes and very different methodologies. I differentiate between meta-analyses and experiments — in general the meta-analyses are more authoritative. Where possible, I have included a journal’s Impact Factor (IF). Those without (IF) in the link have none. Impact Factor is not a perfect metric, so I encourage you to keep an open mind regarding distinctions in the haves and have nots, as well as in the numbers themselves.
There are three main sections for the research below. As usual, they attempt to answer practical questions.They are:
- the overall strategic picture for the framework.
- the specifics within the framework.
- how climbing-specific research fits in.
The Overall Strategic Picture
Why stretch for climbing?
Stretching, either of the dynamic or the static variety, increases the range-of-motion (ROM) of joints. See Lempke et al. (2018; IF: 1.500) and Medeiros and Martini (2018; IF: N/A) and Medeiros et al. (2016; IF: 1.158) and Behm and Chaouachi (2011; IF: 3.67). Climbing-specific studies are unclear regarding the impact of ROM on performance. However, these climbing-specific studies usually define performance broadly – in terms of red-point grade (see Draper et al. 2011; IF:2.811). As a result, a lack of ROM likely does not impair ability in general to climb a “grade” – because climbers can “self-select” (successfully climb) the climbs which require the skill-sets for which they are suited and do not take advantage of the skill-sets for which they are not suited. Additionally, it’s possible to “compensate” for a lack of ROM with alternative skill-sets (especially dynamic climbing) on the same climb.
This series of articles (see “framework” and “case studies”) is designed to provide an option for those who want to compensate less for a lack of ROM, and recommends climbing skill-specific improvements in ROM rather than general ROM. Conclusion: ROM can be increased but it’s unclear from the research how important ROM is to climbing due to a variety of factors, such as the way climbing performance is measured as well as climber compensation.
Why are dynamic stretching and static stretching two alternative strategies?
Many studies look at this differentiation. For an example of a meta-analysis, Kallerud and Gleeson (2013; IF: 7.583) discuss the strategies in relation to sports that require a “stretch-shortening cycle” or plyometric movement, and goes into detail regarding potential trade-offs of the two strategies. For an example of an experiment, Haddad et al. (2014; IF: 2.060) compares Dynamic Stretching to Static Stretching in terms of improving / impairing performance. Improvements / impairments can be generally defined as force and/or the rate of force development, or as activities which require these attributes like jumping, sprinting, etc., and the length of time such improvement / impairment lasts.
Regarding the effectiveness of one strategy over the other, an experiment by Matsuo et al (2019; IF: N/A) showed no differences in flexibility after ten 30-second long sets of static or dynamic stretching. An experiment by Samson et al. (2012; IF: 1.774) suggested a small ROM increase for static stretching (3 sets, 30 seconds) over the use of dynamic stretching (3 sets, 20-meter distance). A meta-analysis by Page (2012; IF: 2.55) cites two studies (Curry, Beedle) and suggests the two approaches have the same effectiveness. Additionally, there’s still a limited amount of evidence (see the 2011 review by Behm and Chaouachi; IF: 3.67) for whether dynamic stretching needs to be run through the full range-of-motion to be effective for increasing ROM.
I chose dynamic and static stretching because of my perception of their popularity. This article won’t go into ballistic stretching (a form of dynamic stretching), or too deep into forms of pre-contraction stretching (e.g. PNF or proprioceptive neuromuscular facilitation), all of which may have uses under specific circumstances. See the Page (2012; IF: 2.55) commentary for a good overview in the International Journal of Sports Physical Therapy. Also, see this meta-review by Cheatham et al. (2015; IF: .229) for some specifics related to timing, cadence, and strategy Conclusion: both dynamic stretching and static stretching are two alternative approaches to increasing ROM, although it’s unclear which is superior for increasing ROM. As noted later, dynamic stretching may have additional positive elements beyond ROM.
Why (and how) do you strengthen?
Active stretching involves the contraction of musculature at or near end ranges of motion. Think of one climber able to lift a foot up to a hold and a second climber in the same situation having to use a hand to grab their foot and place it on the hold. In an experiment by Meroni et al. (2010; IF: 2.702) comparing active and passive stretching, the group assigned to active stretching produced the larger gains in active knee extension. In their experiment on dancers, Wyon et al. (2013; IF: 3.017) showed how the strength conditioning groups and low-intensity stretch groups improved active ROM over the moderate-high intensity stretch group.
The findings from Wyon et al. (2013) apparently confirm previous findings on AROM from the Grossman and Wilmerding (2000; IF: 1.06) experiment and the Wyon et al. (2009; IF: 2.060) experiment. However, I have yet to go over these studies in any depth. Conclusion: climbers need strength at their end ranges of motion, and strengthening and low-intensity stretching may be superior (for ENDROM strengthening) to moderate-high intensity stretching.
Why foam roll (or use other ’tissue pliability work’ such as LAX ball, theragun, etc.)?
In a recent meta-analysis, Wiewelhove et al. (2019; IF: 3.201) discusses the use of foam rolling for warm-up, the circumstances under which “pre-rolling” provides small, short-term improvements in flexibility. However, in the Wilke et al. (2020; IF: 7.583) meta-analysis of the size of the effect of foam rolling – even though researchers identified a large positive effect on ROM – it was not superior to stretching. Conclusion: consider foam rolling (or other tissue pliability work) before stretching as a potential ROM enhancement, but I wouldn’t be overly certain about its efficacy.
Why “Raise Climbing”?
It’s the first element of the RAMP warm-up protocol which you can read more about from Jeffreys’ 2017 and 2007 Professional and UK (respectively) Strength and Conditioning Association papers. You can do cardio to raise your core temperature and heart rate, but it’s recommended that you run through sport-specific movement patterns which help “increas[e] muscle elasticity, increas[e] muscle contraction rates, increase[e] oxygen delivery and uptake, divert blood flow, rais[e] body temperature, etc.” Doing 2-5 minutes of easy boulders or 1-2 easy routes could do just fine – I have my athletes run through specific climbing-oriented skills. Or you could bike. Conclusion: a brief climbing-specific warm-up prior to increasing ROM may be beneficial.
You mentioned a lot of effects of warming-up, can you be more specific?
Sure, I primarily gathered the information from Bishop’s work on warming up (IF: 7.583). In the general article I stated that warming up could raise muscular temperature (above ~35° celsius by a few degrees – which should take between 3-20 minutes) enough to improve muscular elasticity by a very small amount — and the mechanism may not have been found yet. It also may increase oxygen delivery through dilation of the blood vessels, improves aerobic functioning through the use of mitochondria, adenosine diphosphate, and oxygen consumption, changes anaerobic metabolism by facilitating glycogen breakdown, and increasing the ability of the central nervous system to process and react. However, the article also notes it decreases your ability to regulate higher temperatures – one reason why pre-cooling (IF: 3.464) the forearms has been shown to have a performance enhancing effect during hangboarding. Conclusion: there are a number of positive effects for warming up, with the only concerns related to temperature regulation.
Why a “60” second threshold for stretching – does stretching impair performance?
The Behm et al. (2015; IF: 2.518) meta-analysis separated its studies between those with less than 60 seconds from those with more and found a “dose-dependent effect”. However, it should be noted that this study also found that the performance impairment of stretching from static stretching for more than 60 seconds was less than 5%, with practical relevance suggested only for explosive sports like sprinting, jumping and throwing. The Kay and Blazevich (2012; IF: 4.291) meta-analysis found a similar conclusion regarding the 60 second threshold. So did the 2019 review (IF: 3.201) by Chaabene et al. – although they suggest that there is limited information on the “chronic” impact of stretching at any duration.
The 2019 Wiewelhove et. al (IF: 3.201) meta-analysis mentioned earlier creates an argument around the performance impairments of static stretching when balanced against the need for ROM. Additionally, the 2015 Behm et al (IF: 2.518). meta-analysis further qualifies the impairment, suggesting it may impair performance at short muscle lengths but improve performance at longer muscle lengths. According to the Simic et al. (2013; IF: 3.631) meta-analysis, impairment may occur more in isometric (think lock-off) rather than isotonic (think dynamic movement, or traction) performance. Additionally noted by the 2019 Wiewelhove et. al (IF: 3.201) meta-analysis is that the performance impairment effects fall away with time (10 minutes or more), or after a sport-specific warm-up. Conclusion: there is very likely an impairment to certain kinds of performance, and there may be an unfortunate compromise required between the positive and negative impacts of ROM. However, there appear to be multiple mechanisms to mitigate the negative elements.
Is there a “synergistic” effect between foam rolling and either type of stretching?
Mohr et al. (2014; IF: 1.500) and Škarabot et al. (2015; IF: 2.55) suggest evidence from their experiments for a link between static stretching and foam rolling with respect to the hip flexor and ankle. For a counter to the argument, the Smith et al. (2019; IF: 4.291) experiment found that foam rolling and static stretching increased ankle mobility comparatively, but when taken together had no synergistic effect. Additionally, the Kyranoudis et al. (2019; IF: N/A) experiment used 30 seconds of foam rolling and 10 seconds of static stretching and found no synergistic effect. In the only experimental studies I found measuring the combination of foam rolling and dynamic stretching together, authors Smith et al. (2018; IF: 2.060) and Somers et al. (2019; IF: 1.500) found no synergistic effect. Conclusion: The evidence is conflicting.
How long will the prime last?
In their experiment, Smith et al. (2018; IF: 2.060) found a very brief effect (less than 5 minutes) for foam rolling on their flexibility test. Also, they found no effect on flexibility when combined with dynamic stretching. The meta-analysis by Behm et al. (2015; IF: 2.518) on all forms of stretching found a benefit which lasted less than 30 minutes. Conclusion: the prime lasts a short while, which is why I have my climbers attempt to transfer it to the wall as soon as possible.
Why is this a short prime for the climbing session, rather than a framework for long-term improvement?
In a meta-analysis, Freitas et al. (2017; IF: 3.631) discusses why improvements in range-of-motion are likely sensory rather than structural or mechanical. Conclusion: this topic requires a much deeper study of physiology.
How can we mitigate potential decreases in performance due to pursuing mobility?
In their meta-analysis, Wiewelhove et al. (2019; IF: 3.201) argue for a 60 second threshold OR an increase in the window before performance OR a sport-specific warm-up. In their experimental study, Lowery et al. (2014; IF: 2.060) discuss a downside to the use of static stretching to improve range-of-motion, specifically around why indicators of economy and/or short-term endurance may be detrimentally impacted. Conclusion: use a 60-second threshold, more time before performance, or a sport-specific warm-up to mitigate downsides into pursuing additional mobility.
How much should you stretch?
In their meta-analysis, Thomas et al. (2018; IF: 2.132) support the idea of stretching five days a week for at least five minutes per week in order to improve ROM. However, it should be noted that their review was specific to long-term improvement — which I previously said I didn’t want to get into. Dynamic stretching is challenging to prescribe recommendations for, because of the variability in how dynamic stretching is defined across studies. For example, see the sections on dynamic stretching by Behm et al. (2015; IF: 2.518) – including contraction type and stretch intensity. Conclusion: I am more comfortable making recommendations around the short-term prime of stretching toward performance in your next climbing session.
What intensity should I use with stretching?
This is really hard to answer, since one of the major reasons its challenging to compare across studies is due to the difficulty in understanding stretch intensity – which is why duration and frequency are better studied. the Kataura et al. (2017; IF: 2.060) experiment defined it as a percentage (80, 100, and 120%) of “maximum tolerable intensity without stretching pain” and found that 100% and 120% (held for 3 minutes) had greater effects on ROM than 80%. The Freitas et al. (2015l IF: 3.631) experiment mentioned earlier was also supportive of higher intensities for maximum angle increases. The Apostolopoulos et al. (2015; IF: 2.129) meta-analysis categorized studies into gentle, maximum stretch no pain, discomfort and pain but was challenged to come up with anything conclusive. Conclusion: higher intensities may be better for improving passive range-of-motion (this should be viewed as unclear), while we learned earlier that it may not necessarily be the best for improving active range-of-motion.
How long should I hold the stretch for?
This is a tough one, because in general there is a balance to be found between performance improvement/impairment and range-of-motion improvement. The Matsuo et al. (2013); 2.060 experiment looked at 20, 60, 180, and 300 second stretch durations and found the latter two to be most beneficial for markers of flexibility. Conclusion: given the 60 second threshold, it would appear a balance is to be had regarding which parts of your musculature your comfortable seeing a small impairment to, and which joints you need the Active or Passive ROM for.
Your framework discusses spinal mobility – are you worried about training that in youth?
This was a concern for me. I’ve spoken with multiple Physical Therapists (PTs) and Physicians about it and none have expressed a concern to me so long as the training is done within reason. If a climber has a preexisting spinal condition, then a medical professional’s advice should be sought. It also pushed me to do a quick search on PubMed. A review by Sands et al. (2016; 7.583) looked at the potential effect on youth gymnasts, didn’t love the availability of evidence, but ultimately came down on the “backbend” as being relatively safe for youth gymnasts to train assuming prior knowledge of how to train a back-bend. Conclusion: I don’t read anything here that raises my suspicions, but any underlying condition should be approached with caution and medical professionals should be consulted.
What other factors should I be aware of?
For a great overview of other factors, see the Kravitz (IF: N/A) write-up by a Professor at the University of New Mexico. Conclusion: age may reduce ROM in specific areas discussed by this write-up, such as the shoulder and spine, as well as gender differences.
Unfortunately, there is no research I’m aware of which states whether increased ROM is more beneficial for factors like discipline (lead climbing vs. bouldering) or environmental preference (rock vs. competition climbing). This leads us to what climbing research DOES say.
On Climber Range-of-Motion
What does climbing-specific research say about flexibility?
In a review of climbing research, Michailov (2014; IF: N/A) suggests that hip abduction has been a common factor across studies by Grant et al. (1996; IF: 2.811), Mermier et al. (2000; IF: 11.645), and Michailov (2006 — not available in English). Muehlbauer et al. (2012; IF: 2.132) suggests that trunk mobility (specif. flexion/extension and lateral flexion/extension) is trainable but deteriorates quickly. However, Draper et al. (2009; IF: 1.014) studied different measures of climbing flexibility because some of these studies on flexibility (specifically Grant and Mermier) had not found flexibility, in general, to be as important as hypothesized. As a result, they suggest climbing-specific measures of flexibility are needed, and recommended a test which tested loading of a foot in an extreme range-of-motion. One study which tentatively (there were alternative theories) supported the idea that traditional flexibility tests don’t associate well with performance is a study on female climbers by Wall et al. (2004; IF: 2.060), who found that tests of frontal hip flexion, lateral hip rotation, lateral leg flexion, and lateral leg abduction didn’t associate with performance. An analysis by Artoni et al. (2017; Conference Paper) of the drop-knee (lolotte; Egyptian) showed that hip internal rotation equaled knee abduction during the move, and potentially up to maximum knee flexion. Conclusion: specific-climbing moves require specific types of mobility, and each type of mobility is distinct in the way that it is trained and impacted. Identify the move, and figure out the need.
Why do you focus so much on “fitting” a climb?
Research by Amca et al. (2012; IF: 2.811) focuses on what are called “antero-posterior” (front-to-back) vs. “vertical” forces. Basically, the challenge of holding a hold changes as you pull out from the wall vs. pull vertically. Additionally, it changes based on hold size. Not only did they look at grip technique as a possible compensation tool – specifically around crimp climbing allowing for changes in wrist angle, but hypothesized that body position should also be a factor. Additionally, one common methodology across several studies (Jensen et al. (2008; Conference Paper), Cha et al. (2015; IF: 0.97), Artoni et al. (2017; Conference Paper), Shea (2018; Graduate Thesis), and Asakawa et al. (2019; IF: N/A), is using “phases” of different climbing moves to then compare joint angle across climbers. Because the joint angles are often different across the tested groups, it becomes challenging not to suggest that people fit climbs differently – which shouldn’t come as a surprise. What hasn’t been studied is how this relates to compensation.
Additionally, research by Seifert et al. (2015; IF: 2.129) showed that hold orientation (specifically non-horizontal holds, or what I call “directionals”) influences the amount of hip and neck rolling (hip “turn-in”) behavior of a climber, as well as the amount of exploration. While not measuring range-of-motion, the balance of the evidence from Wong & Ng (2008; IF: 3.090 & 2009; IF: 2.253) on shoulder work profiles found strong shoulder internal rotation and extension (think of the “chicken wing”) when comparing climbers and non-climbers. Additionally, work by Rolland et al. (2014; Conference Paper) and Förster et al. (2009; IF: 2.132) looking at female and male spinal posture (respectively) showed increased range-of-motion in the lumbar section of the spine and decreased range in the thoracic spine for the female climbers, and the typical “climber back” in the males (which was not evidenced in the female climbers) with no evidence of increased/decreased range-of-motion compared to non-climbers. Conclusion: it’s hard to identify a synthesis from this information, other than to state that it appears as if (a) researchers have had success measuring ranges of motion in climbers in order to understand their movement, and (b) that there is likely a relationship between range-of-motion and the application of force.
What factors may be associated with “fitting” a climb?
Work by Vigouroux et al. (2011; IF: 1.32), Russell et al. (2012; IF: 0.615), Seifert et al. (2013; IF: 1.928), Seifert et al. (2015; IF: 2.129), Orth et al. (2016; IF: 7.583), Artoni et al. (2017; Conference Paper), van Bergen et al. (2018; Conference Paper), and Vigouroux et al. (2019; IF: 2.811) show how muscle length, co-contraction, reaction force, joint angle & torque, perception-action coupling, perception-action coupling and finger-strength, hold orientation, center-of-mass (CoM), energy systems and workload, hold size, and upper-lower limb coordination all must be considered to create a systematized approach to climbing movement.
Where is the research lacking?
There was some evidence (see above) for shoulder workload (but NOT joint angle), turn-in, high-stepping, and trunk mobility in general, and some small evidence for Fanny-back bend in females. However, I didn’t find evidence for or against “French slab feet” or the double high-step. More importantly, with the exception of the foot raise, all of the research was lacking in some way – usually missing some kind of ROM, work-profile, and/or performance-related research – to make the kinds of assertions that I am. My guess is we need more creative work on climbing-specific flexibility tests, like the adapted grant foot raise, as well as research confirming/rejecting climber compensation for deficiencies in mobility, and if confirmed – how they compensate. We also need more evidence for how these relationships of joint angles work in relation to overall skills (e.g. slab climbing).