The difficult question of sports injuries and disillusionment in youngsters

This good website has some interesting information on the size of the problem of young sportspeople getting injured. Injury rates are going up, to uncomfortably high levels. A serious sports injury is not just a short term issue for a young climber, runner or other sportsperson. It’s one of a few important reasons why so many youngsters drop out of sport before they even finish their teens.

It’s so obviously ironic that parents and coaches both take satisfaction from encouraging kids to take part in sport to foster a lifelong habit of activity and enjoyment. Yet overdoing that encouragement is one of the main reasons behind them ultimately dropping out or getting injured. The number one reason youngsters give for deciding to quit their sport is pressure from parents, coaches or the setup of their sport. So, whatever we are doing, it’s wrong.

Lots of coaches are still wrestling with the idea of whether formal competition in sport is a good idea for kids. There doesn’t appear to be any straightforward answer to that question. The best answer might be ‘it depends’. If the environment is optimal, competition in sport may be quite healthy, if unnecessary. However, it rarely is optimal. There are potential sources of problems everywhere. Therefore, being realistic, maybe no competitive sport until beyond adolescence is better? That is definitely still an open debate.

It’s difficult for parents even to realise how pivotal their role is. For instance, who can blame parents for subconsciously rewarding competition results instead of effort, balance, maturity, sportsmanship and science based training in sport? The very best coaches in professional sport can hardly seem to achieve this, even though they should know better. It’s a tough challenge for parents to assume the role of sports philosopher, role model, coach, sports scientist and sports medic. On the other hand, if you are going to invest time, effort and expense in encouraging your child’s path in sport, you might as well do it properly, in a way that doesn’t leave them either injured or disillusioned and out of sport for good at 13 or 14.

It’s difficult for coaches too. Reliable and useful information on training program design and injury prevention is extremely hard to come by. Moreover, coaches often don’t have enough time with youngsters to provide individually tailored training. In this situation, I think it’s important that they emphasise to both parents and youngsters that the advice they give has limitations, and if they want to make sure they are training safely, they should consider  training themselves to be informed self-coaches, or hire in some more personalised coaching.

In climbing, we are about to enter a dangerous period (in the UK at least) since some new coaching qualifications are coming on-stream. Qualifications, generally speaking, are of course a good thing. However, there can be problems if parents see the word ‘qualified coach’ and don’t think any more about what the qualification means. It’s possible to be a qualified coach in many sports on surprisingly little experience, and unfortunately, depth of knowledge. Parents should be careful to make themselves aware of the level of skill and experience of those coaching their children. Start from the assumption that the coaches are not suitably experienced or resourced to prevent injuries in youngsters, and that you’ll need to consult a range of sources to ensure the best chances of avoiding injury and ensuring youngsters have a good range of influences on their development in sport.

I must say, with my own child, I’d be equivocal at best about encouraging them to get involved in regular competitive sport before adolescence. Non-competitive sport offers so many of the benefits, if not more, without the inherent problems that competition brings. Taking injury risk in particular, non-competitive sports offer the opportunity for more variety and spontaneity in the yearly diet of training, important both physically and psychologically. They also push the focus of performance inwards, to messages coming from the body, rather than outwards, just doing the same training as your peers or trying to keep up with others unrealistically. In other words, they are often healthier all round.

I see advice for youngsters in competitive sport to take breaks in the year from competition. Good advice, although not if they simply stop training completely. Complete rest falls foul of one of the fundamental laws of tendon injuries: “tendons don’t like rest or change”.

I’m talking about parents, coaches and the youngsters themselves so far. They have the immediate responsibility to improve the outcome for the youngster as they move forward with their own life. But what about those higher up, who are in charge of leading sport, spending our money to make sure the potential benefits for all of us are realised? What is the point in promoting sport if it is so hampered by a massive early dropout rate and millions (3.5 million in the US) of injured kids? The idea is that we foster lifelong involvement in sport and physical activity and that sport is something youngsters enjoy over the long term. It’s pretty clear that it doesn’t nearly meet these aims for a big chunk of the participants.

This is a big, serious question, that needs leaders of sport to go right back to basics. When we promote sport, how should it be done? What sports, or sporting practices are healthy in the long term? Should we be promoting entirely different sports and ideas around sport? Probably. I’d like to see data comparing dropout rates between competitive sports and non-competitive sports, such as those based around the outdoors and training. My hunch is that if sporting culture was less centred around rankings or winning/losing and more centred around simple fun, effort, resourcefulness and dedication, that dropout rate would go down.

What specifically should change? It’s a deep cultural change, so no single or simple thing can be targeted. I’d certainly like to see that a session at the gym/leisure centre/sports facility should always be cheaper than a can of cider. Getting an exercise high should always be cheaper than a drug high like alcohol for so many kids who have limited money. Unhealthy goods like cigarettes and alcohol are taxed more heavily to take account of their effects. Why not services? It seems a shame that new sports facilities are not given a more favourable financial climate in which to flourish. At big multi-activity centres, the pizza and cinema tickets could be £1 more expensive so that the indoor snow slope or climbing wall can be cheaper. The many threads of enjoyment of exercise and training for it’s own sake should be promoted over winning and losing. More could be made of urban spaces. Good incentives should be set up for running, cycling, parkour, skateboarding etc clubs to use these spaces. Everyday exercise and sport should be as conspicuous as possible. ‘No ball games’ signs could be banned. If the NHS is going to save money by encouraging us all to be involved in sports, at least some provision is going to be needed to offer proper sports medical care, in recognition that sports injuries do happen and are career ending if left untreated. Surely it’s cheaper to correctly diagnose and repair the ACL tear now than treat the arthritic patient in a couple of decades?

Of course there are countless possibilities along these lines. The cumulative effect would be that youngsters who we do manage to encourage into sport will have enough variety in their activity, so they don’t grow to hate their own sports before they are 15. Moreover, they’ll be less likely to feel the need to enter into serious competition until later, when they are ready. Their parents will be less likely to ‘hang’ their encouragement on success in one sport as well as measuring that success along different lines. And, the youngsters might become more physically conditioned from a longer background in sports before they launch into serious training and hence lower their risk of injury.

Young climbers I’ve met who have been involved in the competitive side of climbing are the only ones I’ve ever seen stop climbing at a young age. I don’t think I can recall ever seeing a climber who was focused on the other aspects of the sport decide to give up. That’s not to say I conclude that competition is bad. It’s just that it can tend to drown out the other reasons for doing sport and become a demotivator after a while.

Whatever is suggested as solutions, the first stage is to really recognise that the injury and dropout rates among youngsters in sport means that what we are doing now is not enough.

The importance of being not normal

Following on from my last post about learning technique, another thought following my recent travels. I was speaking about risk and decision making in bold climbing at the SAFOS seminar at EICA Ratho. One of the other speakers was Mark Williams who gave an excellent lecture summarising some of the fascinating research on skill learning in sport right now.

Mark talked a lot about practice, it’s importance, just how much is necessary to reach your potential (a LOT) and crucially, what good practice consisted of. A key characteristic of good athletes in any sport is that they look for patterns in the vast amounts of basic data we absorb in our day to day practice and play. They don’t just take in the data, they strive to understand it, make sense of it. There’s a big difference. Understanding it means re-running it, either in the imagination (day dreaming, or in scientific terminology, visualisation) or by trying it again and tinkering with some aspect of it in order to understand it better.

In climbing terms this means trying the crux with the right foot on all the plausible options, then coming back next time and trying again, until something in your mind tells you you have ‘understood’ the move. Quite apart from the physical effort of practice, which has the side effect of getting you strong, it takes a huge amount of mental effort and focus.

After his talk I was very eager to ask Mark what, if anything, climbers could do to improve the quality of the practice since in climbing it is difficult to amass thousands and thousands of hours since our little forearms get tired and our skin wears out. 

He told me that a big part of it comes down to this striving to ‘understand’ the movements. He reminded us that truly great athletes stand out because they are by definition ‘not normal’. They verge on an obsessive, compulsive need to go back and analyse every detail.

So is this trainable. Well, much as an obsessive compulsive driven athlete would find it nearly impossible to simply drop this deeply held personality trait on demand, it’s similarly hard to start acting like this if it’s just not you.

However, just by recognising that this sort of time consuming, repetitive practice and reflection is what is necessary, we can at the very least remove some inhibitions that might hold us back from this sort of approach.

In my mind, modern life demands of us the need to preform a heck of a lot of repetitive yet skilled tasks with a great deal of concentration and effort in our working lives, that are lot more boring than training for climbing. I know we are ultimately climbing for fun, but if we are serious enough even to use the word ‘training’ to describe some of our climbing sessions, then surely we can apply a hardcore work ethic and up the ante a little. It's worth noting that one of Mark's points was that even the experts who absolutely love training often feel that the best practice sessions simply have to be so systematic and repetitive that they cannot be enjoyed. 

But the results of those sessions certainly are enjoyed!

A review of strength and endurance in climbing

NB: This article used to live in the articles section of my old site. I’ve reposted it here since it was really popular. Note that it’s nearly ten years old now! 

Background

Sport climbing is the branch of rock climbing involving routes protected by pre-placed anchor bolts. The explosion in popularity of sport climbing and organised competitions have prompted a significant rise in participation and standards in recent decades. The focus of this new discipline is the athletic and competitive aspects of movement on rock (Jones, 1991). Coupled with this has been the development of structured and sport specific training techniques among professional and amateur climbers alike (Goddard and Neumann, 1993; Morstad, 2000). Climbing is a physical activity involving repeated movements of the body against gravity by producing forces on the holds on the wall surface via the upper and lower limbs. A considerable movement technique and psychological performance element is also universally recognised in the climbing related literature. The rise in participation, training and organised competitions in climbing and well documented increases in the occurrence of climbing related soft tissue injuries underlines the importance of research which evaluates the physiology of climbing.

The aim of this review is to critically evaluate the current literature concerning the physiological demands and determinants of performance in sport climbing. Particular focus will be given to the forearm, specifically the finger flexors, and the physiological characteristics and adaptations occurring in trained climbers, which confer increased forearm strength and endurance. Future research objectives will also be outlined within this specific area.

Physiological demands of climbing

Rock climbing involves moving over the wall surface supported by four limbs, described by Quaine et al. (1997) as “vertical quadrupedia” (Fig. 1). Early attempts by climbers to identify key aspects of performance on which to focus their training recognised that the centre of acute fatigue during climbing lay invariably in the upper limbs, especially the forearms (Hurn and Ingle, 1988; Goddard and Neumann, 1993). It was observed that in general, the difficulty of the climbing becomes greater when the wall angle becomes steeper and the holds (particularly handholds) become smaller and further apart. The apparent limitation of the forearm in climbing makes physiological sense given its comparatively small muscle mass, not anatomically designed to support forces comparable with body mass (or exceeding it to produce accelerations against gravity). Morstad (2000) (citing unpublished quantitative analyses) argued that even at wall angles 45 degrees beyond vertical, where the lower limb cannot support much of the body mass in the vertical direction, successful movements must be initiated using the lower limb and trunk in order to reduce peak forces required at the hand holds. Although there are few reports in the climbing related literature of significant lower body fatigue, there is anecdotal evidence that lower limb strength is an advantage on certain types of moves, particularly to maintain contact on the footholds on very overhanging rock (Morstad, 2000). 

Unfortunately, no studies have examined lower limb or core strength in trained climbers.

Bouts of sport climbing last for several minutes with sustained periods of intermittent isometric contraction in the finger flexors. Schadle-Schardt (1998) observed mean climbing times of 4.5 minutes during indoor competition climbing. Thus, sport rock climbing must be considered an endurance event. Few studies have attempted to analyse the movement patterns associated with climbing. Billat et al. (1995) observed that upward movement during indoor climbing occurs intermittently. Video analysis revealed that 63% of the total climbing time was spent ascending (vertical displacement of the hips) and 37% was spent maintaining an ‘immobilized’ position (static equilibrium). In climbing, static equilibrium must be maintained at certain times in order to clip the rope into protection bolts, rest individual fatigued limbs and scan and reach for the next holds (Goddard and Neumann, 1993; Sagar, 2001). Schadle-Schardt (1998) measured mean contact times for the fingers on each hold in competition climbing of 10 seconds with 2.4 second rest periods in between holds (presumably spent reaching the next hold and replacing chalk on the hands).

The angle of the wall surface has been shown to be an important influence on the physiological demand placed on the body due to climbing. Noé et al. (2001) examined the biomechanical constraints of static climbing positions at different angles (vertical and 10 degrees overhanging). When vertical and overhanging quadrupedia were compared there was a large shift in the distribution of the supporting forces to the upper limbs, from 43% to 62% of body weight supported by the upper limbs in the vertical and overhanging positions respectively. Given that rock climbs can feature angles of up to 90 degrees beyond vertical, this magnitude of shift appears remarkable and certainly explains the physiological findings (described below) of performance studies which showed much greater energy expenditure and lactate production with only small increases in angle beyond vertical (Watts et al., 1998).  Unfortunately this is the only study to compare supporting force distribution at different angles. Further studies examining a greater range of wall angles would give further insight into the dependence on the upper limbs for support at overhanging angles.

Finger flexor strength has been extensively measured in trained climbers by a number of studies. The conclusion of these studies appears to be that trained climbers have higher finger strength compared to controls, although methodological differences have provided varying results (Sheel, 2004). An early study by Watts et al. (1993) observed no differences in absolute values of hand-grip strength measured by hand-grip dynamometry in world class climbers and controls. It was suggested that climbers may not need high grip strength per se. Rather, strength to mass ratio was thought to be a more important variable and this was significantly higher in climbers (due to low body mass). Several later studies have measured hand-grip strength, some observing no differences in absolute forces between elite climbers and recreational or non-climbers (Ferguson and Brown, 1997; Watts et al., 2003) and others observing that climbers have higher grip strength (Bollen and Cutts, 1993; Grant et al., 1996, 2001). Grant et al. (1996) recognised that grip strength dynamometry might not provide an accurate assessment of the type of strength required in rock climbing, and developed a climbing specific device for measuring finger strength that simulated more closely the grip styles used on climbing holds (Schweizer, 2001) (Fig. 1, 2). All subsequent studies using this type of grip specific measurement have recorded higher finger strength in trained climbers (Grant et al., 1996, 2001, 2003; Quaine et al., 2003; MacLeod et al., unpublished data; Reid et al., unpublished data). Although climbing moves often involve hanging or moving underneath horizontally aligned finger edges, the types of moves and positions experienced in climbing are extremely varied and it seems likely that some may involve a force requirement greater than that needed to support the body in the vertical direction (such as using ‘undercut’ holds) (Goddard and Neumann, 1993; Sagar, 2001). This view would challenge Watts’ suggestion that climbers do not need to produce large absolute forces. Unfortunately no biomechanical analysis has been carried out on a range of climbing positions/movements to date, in order to determine the supporting force requirements of climbing positions.

Anthropometric characteristics of climbers

Several studies have measured anthropometric data in various populations of climbers. Watts et al. (1993) studied a highly homogenous group of climbers; semi-finalists in a sport climbing world cup event. This study observed that this group were characterised by low stature and very low percentage body fat values (4-14% for men, 10-20% for women).  This finding has been supported by several subsequent studies of trained climbers (Binney and Cochrane, 1999; MacLeod et al., unpublished data; Mermier et al., 2000; Sheel et al., 2003; Watts et al., 1996, 2000, 2003) and percentage body fat has been proposed as a key predictor of sport climbing performance. Grant et al. (1996, 2001, 2003) failed to observe any differences in percent body fat between trained climbers and controls or other athletic groups. However, the absence of significant differences might be attributable to the comparatively low ability of the climbers compared to the studies mentioned above and/or different equations used to estimate body fat percentage..

It is logical that a large body mass or any excess body fat would be disadvantageous in elite level climbing as body mass must be repeatedly moved against gravity. However, it is well known that climbers have long considered excess body fat to be a disadvantage and control it strictly. It is also considered advantageous to avoid hypertrophy training of lower body muscle groups. Hence, the question remains whether body mass and body fat percentage are important determinants of climbing performance or merely a feature of climber’s training patterns (Farrington, 1999). It is conceivable that any performance advantage conferred by maintaining very low body fat may be offset by problems with consumption of sufficient caloric energy to support a rigorous training regime. Longitudinal study of the effect of manipulation of percentage body fat on climbing performance would yield more meaningful data on the subject (Sheel, 2004). Low stature might be an advantage in climbing due to volume-mass ratios. However, any advantage may be offset to some degree by a reach limitation in shorter climbers (Sagar, 2001).

Reach is universally recognised as a common limitation on climbing moves among rock climbers. This has led to ‘ape Index’, a measure of reach relative to height, (arm span/height) being proposed as a performance predictor. Watts et al. (2003) measured ape index in adolescent competitive climbers and found small but significant differences relative to age matched controls. There was no relationship between climbing ability and ape index. Watts suggests this may be due to the lack of variability between climbers. Grant et al. (1996, 2001) found no differences between trained climbers and controls for leg or arm length. The significance of these findings is limited due to the small sample sizes and ability level of the climbing groups. It is not possible to make any conclusions about these variables from the available data.

Given that climbers perform repeated contractions of the forearm muscles and appear to possess greater finger strength than controls, it has been hypothesised that climbers will develop greater forearm muscle mass. Muscle force is highly correlated to muscle mass, whereas no consensus has been reached on whether force per unit muscle mass is influenced by training (Fukunaga et al., 2001). Only three studies have attempted to measure forearm muscle mass in trained climbers and controls. MacLeod et al. (unpublished data) measured forearm circumference is 12 elite climbers and found significantly higher forearm circumference to body mass ratios in climbers. The absence of significant differences in absolute values is explained by the difference in body mass between the subject groups. This finding agrees with those of Watts et al. (2003) who observed similar forearm volumes in competitive climbers and controls, despite the climber’s lower stature and body mass. Reid et al. (unpublished data) measured forearm circumference in height and body mass matched trained climbers and controls. Climbers had higher forearm circumference although the difference was not significant. Again, the low variability in this anthropometric measure calls for further study using larger subject groups and more sensitive methods of measurement.

Mermier et al. (2000) attempted to quantify the relative contributions of anthropometric variables (Height, mass, leg length, percentage body fat), hip flexibility and training variables (grip, shoulder and leg strength, grip and hang endurance, lower body anaerobic power) in a study of 44 trained climbers of varying standard. It was concluded that trainable variables were much more important predictors of climbing ability and that anthropometric and hip flexibility variables were very poor predictors of ability. It was concluded that climbers do no need to possess particular anthropometric characteristics to be successful sport climbers.

 

Flexibility

Body flexibility is another variable which is thought to be relevant in climbing performance as the ability to reach distant holds and maintain positions at extreme joint angles can provide a clear advantage on certain climbing moves (Goddard and Neumann, 1993; Sagar, 2001). Grant et al. (1996, 2001) measured hip flexibility in trained climbers and controls but observed no significant differences. However, issues with the standard of the climbing group discussed above may have affected the validity of the comparison. An intervention study into the effect of flexibility in competitive climbers would yield more useful information.

Fatigue factors in climbing

To successfully complete a sport route, climbers must maintain the ability to make high force, intermittent isometric contractions of the finger flexors. Indeed, competition routes are designed to have progressively more difficult individual movements (the purpose being to separate out climbers of different abilities). Failure to produce the required finger force, coupled with burning, stiff and painful sensations in the forearm (known as ‘pump’) are recognised as being the dominant symptom of fatigue associated with failure to complete a climb, resulting in a fall (Goddard and Neumann, 1993). Finger endurance has been identified as a key attribute of elite level climbers by several studies (Binney and Cochrane, 1999; Ferguson and Brown, 1997; MacLeod et al., unpublished data; Quaine et al., 2003; Reid et al., unpublished data).  Grant et al. (2003) demonstrated that intermediate level climbers do not differ from other athletic groups with respect to finger endurance.

The intermittent isometric contractions seen in climbing are unusual in sport generally (Spurway, 1999). The nature of isometric exercise has several important consequences for the development of muscular fatigue with repeated contractions. Asmussen (1981) characterised this type of contraction as causing significant increases in intramuscular pressure. This change causes blood to be squeezed out of intramuscular blood vessels and hinders or even completely stops blood flow through the muscle. Blood flow can only resume when the contraction ends. The magnitude of increases in intramuscular pressure, and hence blood flow occlusion, is dependent on the intensity (that is, the percentage of MVC) of the contraction. It is thought that contractions below 10-25% of MVC receive adequate blood flow and can be maintained without muscle fatigue (Asmussen, 1981). Above 45-75% MVC, blood flow is completely occluded in the forearm and fatigue patterns mimic those where artificial occlusion is present (Barnes, 1980; Heyward, 1980; Serfass et al., 1979). Between these values, blood flow is reduced and fatigue occurs, but at a slower rate. There is considerable variability in the extent of occlusion in a given subject and muscle due to the following factors: the prevalent muscle fibre type, the size and structure of the muscle. MacLeod et al. (unpublished data) measured finger endurance using a climbing specific protocol (a ‘crimp’ grip with 10/3sec contraction/relaxation ratio) in trained climbers and controls. The intensity was 40% MVC and times to failure in the climbers were similar to the total climbing times observed in a world cup climbing event (Schadle-Schardt, 1998). The authors suggested that 40% MVC may be representative of the average MVC percentage required from the finger flexors in climbing.

Carlson and McGraw (1971) observed lower isometric endurance in subjects with higher MVC and hypothesised a negative relationship between these variables. Based on these findings, it would be anticipated that the climbers would have shorter endurance times as they exhibit higher MVCs than non-climbers. The literature has demonstrated that this is not the case and it is thought that adaptations present in trained climbers appear to offset any disadvantage due to higher force production (MacLeod et al., unpublished data). Quaine et al. (2003) demonstrated that muscle fatigue, measured by the decline in median frequency of surface electromyogram (EMG) in the active forearm muscles, in a climbing specific finger endurance task was delayed in elite climbers compared to non-climbers. The rate of fatigue in climbers was twice as slow as controls at 80% MVC. The authors concluded that this delay was due to climber’s enhanced ability to recover between contractions, speculating that enhanced vasodilation during rest periods accounted for the climber’s advantage. Reid et al. (unpublished data) also observed EMG fatigue using a similar protocol to MacLeod et al.. Trained climbers and controls had similar times to fatigue and decline in EMG median frequency. However, the climbing group had higher MVC and hence produced significantly higher force for a given test period. Watts et al. (1996) measured maximum hand-grip force before and immediately after a climbing task to exhaustion. Hand-grip MVC decreased 22% after the climbing task and remained depressed for 20 minutes post-exercise. However, later work by Watts et al. (2000, 2003b), which also measured maximum hand-grip and finger strength before and after a fatiguing climbing task showed no drop in ability to exert maximum force. Watts et al. (2003b) showed no change in root mean squared EMG values pre and post climb. However, change in median frequency was not measured. It seems possible that the results of Watts et al. (1996, 2000, 2003b) may be affected by the delay in measuring MVC after the climbing bout ended. It is noted that the measurements were taken within one minute of failure on the climb. However, Quaine et al. (2003) points out that the difference in endurance capacity between climbers and non climbers is due to an ability to recover significantly in the short (5 seconds in this case) rest periods between contractions. Future study employing continuous EMG data during a climbing or climbing specific task is required to fully establish whether loss of finger strength occurs during strenuous climbing.

MacLeod et al. (unpublished data) pointed out that loss of fine muscular control may be an additional causative factor for failure to complete a climbing task. Climbing movements require precise timing of force development, as well as extremely rapid and complex movements of the body. Indeed, it is often necessary to lunge for handholds which require precise placement of the fingers in the most advantageous position on the hold to provide adequate support (Goddard and Neumann, 1993; Sagar, 2001). It seems plausible that falls could be caused even by small decrements in force production on such precise holds, or by loss of coordination due to the effects of muscle fatigue on muscular control. Bourdin et al. (1998, 1999) observed a hierarchical organisation of reaching movements between climbing holds (measured on a climbing ergometer). It was noted that reaching duration was shortened by increased postural constraints, regardless of the destination hold size (and therefore accuracy requirements). This factor appeared to override the speed/accuracy trade-off seen with seated or standing reaching movements. Postural constraints are greater in vertical than overhanging climbing, however, overhanging positions are characterised by greater force requirements from the fingers to support body weight (Noé et al., 2001). It seems plausible that this factor would produce an additional demand for shorter reaching durations. This hypothesis has anecdotal support in the climbing literature (Morstad, 2000). Future studies using a similar protocol to that of Bourdin et al., comparing the organisation of reaching and grasping movements at different wall angles would help resolve this question. Such a study has not been undertaken to date.

Physiological responses and adaptations to climbing

Climbing involves whole body movement against gravity for sustained periods. It appears that the upper body is the primary centre of fatigue in climbing, but the role of the lower body in climbing movements has yet to be quantified (Sheel, 2004). Several studies have measured whole body VO2 during climbing on an indoor wall or climbing treadmill. These studies have shown that VO2 rises during climbing to a moderate proportion of running VO2 max (Billat et al., 1995; Watts et al, 2000). VO2 values are markedly variable between studies, but this can be explained by differences in testing protocol and subject groups. It appears that average VO2 during difficult sport climbing is about 25 ml.kg.-1 min-1 (Sheel, 2004). However, values of 43.8 ml.kg.-1 min-1 were recorded in a maximal treadmill climbing task to exhaustion (Booth et al., 1999). Sheel et al. (2003) showed that climbing VO2 was related to climbing difficulty, with VO2 values reaching 45% and 51% of cycle ergometer VO2max for an ‘easier’ and ‘harder’ climb respectively. However, Watts et al. (1998) observed no increases in climbing treadmill VO2 as treadmill angle increased (four minute climbing bouts at angles between 80 and 102 degrees). It is suggested that arm specific peak VO2 may have been reached, rendering further increases impossible when climbing angle became steeper. In addition, the active muscles may be completely blocked from general circulation during contractions, limiting large increases in VO2 (Asmussen, 1981).

Several studies have measured blood lactate concentration after a climbing bout (Booth et al., 1999; Billat et al., 1995; Grant et al. 2003; Mermier et al., 1997; Watts, et al., 1996, 1998, 2000). The values for blood lactate following strenuous climbing range from 2.4 to 6.1 mmol/l. This large variation is likely to be attributable to different modes of climbing (wall, treadmill or simulated climbing), different subject groups and different intensities of the climbing bouts. Watts et al. (1998) demonstrated that lactate production is related to climbing angle. This finding is supported by Mermier et al. (1997) who observed that lactate production is related to climbing difficulty. Large increases in blood lactate may be surprising given that climbers report that muscular pain and fatigue lies predominantly in the forearm. The small muscle mass of the forearm would not be expected to produce large amounts of lactic acid. However, as mentioned above, the relative contributions of different muscle groups to movement on rock have not been quantified to date. Given that such increases in lactate are observed, and that blood flow may be partly or wholly occluded in the forearm during intermittent exercise at high intensities, it seems likely that lactate may accumulate to high concentrations within the forearm muscles during climbing. No studies have compared lactate production in elite and novice climbers in order to establish whether there is any adaptation in trained climbers which affects metabolite build up during climbing (see section below on blood flow). Grant et al. (2003) observed greater increases in blood lactate during a climbing specific forearm endurance task. It is possible that greater blood lactate could be an indicator of increased lactate clearance from the exercising forearm due to increased blood flow.

It has been suggested above that climber’s superior finger endurance may result from an increased ability to recover from isometric contractions. Ferguson and Brown (1997) measured forearm blood flow by venous occlusion plethysmography after intermittent isometric contractions of 40% MVC. Trained climbers had significantly higher vascular conductance following the exercise bout. The authors concluded that climbers demonstrate enhanced vasodilator capacity, which is attributed to adaptations of the local vascular bed, including increased capillary density, capillary cross-sectional area or alterations in local dilator function related to endothelial change (Delp, 1995; Smolander, 1994; Sinoway et al., 1986; Snell et al., 1987).  MacLeod et al. (unpublished data) monitored changes in forearm blood oxygenation continuously during a climbing specific endurance test using near infra-red spectroscopy (Fig. 3).  Oxyhaemoglobin levels in trained climbers were significantly lower during contraction phases (attributable to higher force production) than controls, but recovered to a significantly greater extent during 3 second rest phases. It was concluded that ability to restore forearm oxygenation (by increased blood flow) was an important predictor of success in an endurance test of this type.

The pressor response to isometric exercise has also been identified as a variable of interest. Isometric exercise causes increases in both systolic and diastolic blood pressure (BP) greater that would be expected for equivalent dynamic exercise, reaching a peak at the point of fatigue (Asmussen, 1981). The large increases are caused both by rises in intramuscular pressure, exceeding systolic pressure and blocking blood flow into the active muscles, and sympathetic vasoconstriction in other tissues in order to re-direct blood flow to working muscles. Increased sympathetic activity is triggered by the muscle metaboreflex and a central command component. Significant rises in systolic and diastolic BP have been observed during a climbing specific task (Ferguson and Brown, 1997; MacLeod et al., unpublished data). Increasing central arterial BP has been shown to enhance force production during isometric contraction (Wright et al., 2000). MacLeod et al. hypothesised that an increased pressor response would confer a performance advantage in the endurance tests by opposing occlusion caused by the muscular contraction, thus permitting increased intramuscular blood flow. No differences were found between BP responses for trained climbers and controls during a climbing specific task. Ferguson and Brown (1997) observed an attenuated BP response in trained climbers, an adaptation known to occur following endurance training. The authors hypothesised that the reduction in muscle sympathetic nerve activity could be caused either by reduced chemosensitivity in of the metaborecetptors or reduced build up of metabolites in trained individuals. The latter possibility would seem to be contradicted by the evidence of MacLeod et al. who found significantly lower muscle oxygenation during climbing specific contractions, and by those of Mermier et al. (1997) who found that lactate production is related to climbing difficulty. However, further study is required in this area to fully elucidate the responses and adaptations of pressor response in trained climbers.

It is concluded from the available data that sport climbing relies on both aerobic and anaerobic energy pathways. It seems likely that increased climbing difficulty and/or angle causes more reliance on the anaerobic system. Further research is required, examining both central and peripheral adaptations and responses to climbing, in order to fully understand the physiological determinants of climbing performance.

Summary

Current understanding of the mechanical and physiological demands of sport rock climbing has revealed that performance is dependent on a wide array of physiological, anthropometric, movement technique and psychological factors. The centre of physiological fatigue and performance limitation lies predominantly in the forearm musculature. It appears that successful sport climbers have developed greater finger strength and endurance than other populations. As climbing difficulty increases there may be increased reliance on the anaerobic system, particularly in the forearm, coupled with increased lactate production and blood pressure. Enhanced climbing specific endurance may be the result of an increased forearm vasodilatory capacity allowing better recovery from intense contractions of the finger flexors.

Future research objectives have been noted in the text. Much of the research to date has focused on comparison between trained climbers and controls and is descriptive in nature. It seems likely that the results of several studies seeking to establish their physical characteristics have been weakened by problems with availability of subjects of appropriate training status (Sheel, 2004). The diverse nature of the sport of climbing, with its many disciplines compounds this problem. Future studies of this nature should seek to recruit subjects who participate in similar patterns of climbing activity, for example sport climbing competition teams.

References

Asmussen, E. (1981). Similarities and dissimilarities between static and dynamic exercise. Circulation Research, 48 (supp.1), 3-10.

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New research published on finger endurance

My undergraduate research project investigating determinants of finger endurance in trained climbers was recently published in the Journal of Sport Sciences. You can see the details here or access the full paper if you have access to the scientific journals through an academic or other institution. A huge thanks to Stan Grant for encouraging me to keep going with the log preparation of the manuscript for submission and to everyone that worked with me on the paper and volunteered for the research itself.

We observed that climbers were not dramatically better at tolerating occlusive isometric contractions of the finger flexors (as you get in difficult climbing), but were surprisingly good at sustaining long periods of intermittent high force isometric contractions compared to untrained people. This could be down to an ability to perfuse the muscles very rapidly and recover from the contractions while reaching for the next hold. Not surprisingly, we also observed yet another confirmation that pure finger strength, and especially finger strength to weight ratio was a strong predictor of climbing level.

The intermittent isometric muscle contractions of our fingers in climbing are not that common in strength and endurance dependent sports, and there is still much to be learned about the exact causes of failure to maintain force output and sequence of chemical events that happen deep in the exercising muscle during fatigue. 

Big up to anyone out there willing to take up this mantle and help us to learn more about the physiological limitations in climbing. The continued dramatic rises in the level of ability of the worlds top climbers really shows that we are nowhere yet, either with our understanding, or what could be done with it.

Cold Treatment revisited

A great many of you have commented, emailed etc to say that my videocast and articles on finger pulley injuries were helpful – thanks to all of you. It’s been really interesting that so many of you have tried the cold treatment I suggested with such positive effects.

I thought I’d let you know that I’ve heard feedback from someone who has used the cold treatment (same protocol – 30 mins immersed in the bucket, twice per day for several months) for an elbow injury and reported excellent results with much speeded rate of progress of healing and it allowed continued climbing during the rehab process. Good news.

Such anecdotal reports are all we have to go on at present until someone does a decent longitudinal study. All you sports science/medicine students who email me to ask for research project ideas – now there’s an excellent one worthy of a paper in BJSM if you have the guts to put in the work!

Any of you out there tried it on a shoulder injury?

New research review - Audry Morrison interview

Audry Morrison and Volker Shoffl have just published a review of the available research relevant to young climbers in the British Journal of Sport Medicine As well as collating some interesting data on studies carried out within climbing, it also draws on other useful sources of information to give us a better picture of the effect of climbing and training on the young body. Not everyone has access to the scientific research press or can digest the information it offers; so I asked Audry if she would answer a couple of questions for this blog.

Young climbers are always asking (and if they don’t they should be!) “how much should I train at my age?” and “what harm can training at a young age do?” The review underlines the need for young climbers and their parents to educate themselves as to what activities and intensities are safe at given ages, and what can be done to minimise risks of permanent alteration or injury to the developing tissue.

Audry Morrison

Non-climbers are always noticing my hands and commenting that they look very different to 'normal' hands. What changes should climbers who train regularly expect in their hands and are there any negative consequences to consider?

Audry: Climbing is certainly a ‘load-bearing’ sport, with the fingers supporting a lot of this ‘load’. Those bones that are most involved with this ‘load-bearing’ or ‘resistance’ exercise are constantly remodelling themselves in response to this type of exercise. Bones are not static. So in a veteran adult climber’s fingers there is up to a 50% increase in the tendon width size (a few years to achieve), a thickening of the collateral ligaments here too, the bones in the fingers physically remodel themselves to become wider/thicker to better accommodate this loading (especially at joints, notably the middle joints), and the fingers just tend to be thicker. How much the finger bones thicken is in direct relationship to the number of years climbing, hours spent training, and climbing ability level. Repeated over training can create micro traumas that collectively can result in stress fractures, ganglions, pulley strains/rupture, tendon nodules, finger nerve irritation, arthritis, etc.


Negative consequences to consider
Good bone remodelling to create strong bones also relies on the assumption that good nutrition is also in place…. like not drinking a lot of soft drinks. An American study found females around age 20 had osteoporosis (brittle bone) similar to that of a 70-year-old because of the volume of soft drinks they drink. These drinks act to limit the amount of calcium your bones can absorb when they remodel themselves. Also, if calcium intake poor, the body will ‘steal’ calcium from other bones to use when remodelling the bones that are getting most of the resistance workout.

A lot of climbers quite rightly have concerns about their fingers and hands. We ask a lot of fingers when climbing, especially at a high ability level.

This is probably obvious, but high ability climbers generally experience more injuries, especially to the fingers, because of the greater mechanical stresses and weight-bearing loads to the fingers. ‘Crimp’ position exerts the greatest compressive force to a finger joint cartilage, compared to the ‘open hand’ position that is more protective and also allows you to climb for longer. Over gripping holds will limit climbing performance because of the direct knock on effect of increasing blood pressure and heart rate, increasing stress hormone levels etc that in turn influence and change metabolites in the forearm so you get pumped quicker.

Climbers should continually assess the full range of motion in all 3 joints of each finger. Can you place your hand palm down so that it is flat on a table surface? If any of the fingers can’t go flat, it may suggest Dupuytren’s disease. This used to be confined to those aged 40-60 who worked manually that created micro traumas to the fingers, though there is also a North European genetic predisposition to it. Unfortunately even young climbers have various stages of Dupuytren’s, that if severe, requires an operation to straighten the finger. But some NHS hospitals a while back refused to perform this surgery any more along with some others as a cost cutting exercise.

In one good study examining osteoarthritis in 65 veteran adult climbers (average age=37.5, climb experience=19.8 years, grade=5.12c) compared to non-climbing age-matched controls, there were five specific joint areas in the climber’s fingers that scored significantly higher than the controls. But having said this, the overall osteoarthritis scores between both groups were similar.

What do you think are the main things young climbers should keep in mind to progress quickly and safely to the upper levels in climbing?

Audry: Below the age of around 12 (pre-pubertal), no youngster has the ability to adapt to either aerobic or anaerobic exercise as would happen in an adult. There are many adaptations in their body that prevent this from happening. But they can learn movement well, and they most definitely should be participating in sport (all sorts). It’s not known when specialisation in climbing should take place. They must be encouraged to learn very good technique because they don’t have the strength, have immature pain barriers, etc. In younger children, actually demonstrate what they are doing wrong.

Elite young climbers will also have thickened finger bones. What’s critical for young climbers is that their finger bones grow to their full length around age 16.5, and that this is not interrupted by finger training too intensively. Damage (temporary or permanent damage) can occur when young climbers undertake extensive finger strengthening exercises. This is especially so when they try to compensate for their increased weight when they have their final growth spurt around age 14-15. Some 20% of adult height is achieved in this final growth spurt where skeletal mass increases twofold and a lot of muscle can be packed on. Ligaments and tendons have not yet adapted to these increases in bone length and load, and increasing levels of certain hormones can also weaken the joints. The training focus must be on ensuring good technique/efficiency (always!) and on volume & diversity of route, rather than doing any finger strength training those elite adults do.

Also check for any curvature of spine, tight shoulders that have a rolled hunched look. If so, much more stretching needs to be carried out, possibly physiotherapy or medical intervention if severe.

Check feet too. See if there is any pain or deformities, or loss of nerve sensation. If any of these is the case, the shoes are too restrictive. Feet grow in a linear manner length and width from ages 3-12 (in females) and to age 15 in males. Height is highly correlated to foot growth to the age of 18.

Thanks for answering those questions Audry and well done on the research. Its quite a striking figure that tendon width increases so much – when you consider the effects on the cross sectional area of a doubling of tendon width it seems even more impressive. But we ask so much of our fingers in climbing and muscles work at such a mechanical disadvantage that I suppose it’s not so much of a surprise that the adaptations are so striking. I’ve certainly noticed a marked thickening of my PIP joints over the past two years and more aches and pains in them than before.

I think the key takeaway from all this is to read and educate yourself before you launch into the training, rather than once you start having problems. At the same time, all these consequences to getting training wrong as a youngster doesn’t mean you cant push yourself until you are adult. It just means that there are trade-offs between going hard when you are still growing and accepting and managing some consequences from it. But most of the negative consequences should be avoidable with healthy respect for the body. Just look at climbers like Fred Nicole who was climbing F8b+ at 16 and has been bouldering at the cutting edge right through to his late thirties with seemingly no breaks – inspiring.

You can see the abstract for Audry’s paper here. You can view the full text if you have an ATHENS password.

Dieting - eating more with less calories - how to manage it

Climbers who are trying to lower their weight to climb better are rightly always on the lookout or strategies that actually work to make the process any more achievable. The appetite is a powerful adversary against will to get to a low body fat percentage, and for most they’ll never win the battle. A lot of the weapons in the dieters armoury focus on the fat and carbohydrate composition of food and how best to manipulate total calorie intake.

Some new research in the American Journal of Clinical Nutrition this month has underlined the fact that there is another dimension to winning over appetite; the calorie density of food. Basically, there are some foods that are more calorie dense, meaning that you end up eating a lot of calories before you feel full. Foods that have a high water content allow you to eat what feels and looks like a lot of volume, making you feel full with less calorie intake than ‘drier’ food. Fruit and vegetables are obvious foods with high water content. I’ll make up some more ideas for ‘calorie poor’ foods soon.

This study found that a group of volunteers eating foods higher in water and lower in calorie density lost more weight than another group eating normally, and that they ate 25 percent more food (by weight) at the same time as feeling less hungry.

In practice – you’d have to eat about 4 apples to get the equivalent calories of one Snickers bar. I know which would make me feel more full!