1.0 Introduction

The popularity of the sport of rock climbing has increased significantly in recent years. Originally seen as a method to train for alpine climbing and mountaineering, the last few decades has seen climbing develop into a competitive sport, with the introduction of the climbing world cup in 1989 (Billat et al., 1995). The development of indoor climbing walls and improvements in equipment technology has seen not only significant increases in climbing performance but also large increases to the number of people taking part in rock climbing as recreational pursuit.  As rock climbing is a relatively new sport, research in the area is still quite limited compared to other sports (Horst, 2003)

 Free rock climbing involves the ascent of a climb or route using only the rock to pull on. The leader clips the rope into specialist gear or protection to prevent him or her hitting the ground, in the event of a fall. In sport climbing this protection comes in the form of permanent bolts, making the route safe, thus allowing the climber to concentrate on climbing as hard as possible. Traditional climbing requires the leader to place temporary protection in the form of specially designed equipment. This provides an element of adventure or risk to the climber as the abundance and quality of protection to be found on a route can vary greatly (Shepherd, 1993). This type of rock climbing is commonly practised in the United Kingdom as the use of bolts is widely banned by either landowners or the British Mountaineering Council. (BMC, 2004)

Climbing uses a subjective grading scale to quantify the difficulty of each route. A route's name and grade are given by the first ascendant, with subsequent ascendants confirming or altering the grade. The system is open ended with UK grades currently ranging from Moderate to Extremely severe 10 (E10). Traditional climbing typically follows the UK system, with sport and indoor climbing following the French (F) or Yosemite Difficulty System (YDS).

See Grade Comparison

Physiological research to date has focused mainly on investigating the anthropometric characteristics of elite climbers and the energy costs of climbing (Watts, 2004).  Current research has found that heart rate (Billat et al., 1995; Mermier et al., 1997) and blood lactate increase significantly during climbing (Booth et al., 1999).  This was affected by climbing difficulty (Mermier et al., 1997; Janot et al., 2000), time to climb and climbing gradient (Watts and Drobish, 1998), with greater increases found during steeper sections of climbing.  Heart rate and Rate of Perceived Exertion (RPE) increases have been found to be greater in less experienced climbers, due to psychological stress (Mace, 1979) and inefficient climbing technique (Janot et al., 2000).

 Unlike most other sports, climbing does not elicit a linear relationship between heart rate and oxygen uptake (VO²), with a greater heart rate response found in relation to V0² (Mermier et al. 1997). Various researchers have attributed this to the large amount of upper body isometric work involved in climbing (Booth et al., 1996; Sheel et al., 2003) and to the psychological stress (Mace 1979).

Anthropometrical research has found that successful climbers were small in stature, with high relative strength and low body fat percentage (Watts et al., 1993). Shoulder endurance, hip flexibility and finger strength have also been found as significant factors when predicting climbing ability (Mermier et al., 2000).

 However, the current physiological research involving climbing has focused mainly on indoor climbing, with no current research actually examining climbers in an applied setting.  Only Booth et al. (1999) has examined rock climbers on actual rock. This study found greater heart rate increases during outdoor climbing, suggesting there may be slightly different physiological demands placed upon a climber during outdoor climbing, than when climbing indoors at the same level. Climbing literature has frequently warned inexperienced climbers of the dangers of comparing the two:

Climbing E1 on the (indoor) wall does not equate to the same in the real cragging (outdoor climbing) world (Shephard, 1995- cited in On the Edge, 51)

The controlled and relatively comfortable environment of an indoor climbing wall is significantly different to climbing on actual rock (Lewis and Cauthorn, 2000). Therefore, the physiological requirements of climbing on an indoor wall or lab may be different physical, psychological and technical demands of climbing outdoors (Lewis and Cauthorn, 2000). This suggests that the research carried out indoors may not be useful when applied to outdoor climbing.

Another issue with the current research when applied generically to climbing is that there are several varieties of climbing, such as ice climbing, aid climbing, bouldering, sport and traditional rock climbing (Horst, 2003). Most of the research to date has investigated rock climbing from a sport climbing perspective, as this style maximises safety and enables the climber to focus on the physical difficulties involved in climbing (Watts, 2004). Research carried out involving sport climbing should therefore be applied specifically to this discipline of climbing and not generically to all aspects of the sport (Mermier et al., 2000).

  The physiological demands of rock climbing may also be influenced by various external conditions, such as the nature of the route and type of rock (Goddard and Neumann, 1993). Research that has been carried out on indoor climbing walls and climbing treadmills, has found that physiological responses are influenced by steepness (Watts et al., 1998), difficulty (Mermier et al., 1997, Janot et al., 2000) and the technical qualities of the route (Billat et al., 1995).  Climbing literature suggests that this may be true for outdoor routes, suggesting that success on one route may not necessarily translate to another, of the same grade or even below, due to the technical and physical requirements of different routes:

One man's F9a will be another woman's F8c+ or F9a+ (McClure, 2003- cited in On the Edge 132).

Another quote from McClure (2003) compares two of Britain's hardest sport routes, Hubble and Progress, both graded F8c+:

In running, Hubble would be the 100m, Progress the 800m- not many people do well in them both (McClure, 2003- cited in On the Edge 132).

  This could mean research carried out at one venue or type of rock is specific to that type route only and not relevant for other routes even at the same standard of difficulty. Only Mermier et al. (1997) has compared the responses to climbing two different routes at the same grade, however the study only used four subjects.  No current study has compared data from two outdoor rock routes.

1.1 Purpose

The purpose of this study, therefore, was to examine the physiological responses of outdoor traditional rock climbing. The aim was to provide some normative data, regarding the physiological demands of climbing two types of climb or route, graded the same, in traditional style: 1) an overhanging route (angle > 90°) and 2) a slab (angle < 90°). The variables that were examined and compared were; post climbing Blood lactate, mean and maximum heart rate throughout the climb, post climbing RPE, and, pre, and post climbing grip strength changes.

1.2 Hypotheses

Hypothesis 1: - Heart rate will increase significantly during climbing.

Hypothesis 2: - Grip strength will be significantly reduced after climbing.

Hypothesis 3: - Heart rate will be significantly greater during route 2 (steepness > 90°) than during route 1 (steepness < 90°). 

Hypothesis 4: - Reductions in grip strength will be significantly greater after route 2 (steepness > 90°) than after route 1 (steepness < 90°).

Hypothesis 5: - Blood lactate concentrations will be significantly greater after route 2 (steepness > 90°) than after route 1 (steepness < 90°).

Hypothesis 6: - Rate of Perceived Exertion will be significantly greater after route 2 (steepness > 90°) than after route 1 (steepness < 90°).

Hypothesis 7: - Decreases in grip strength will be significantly related to post climbing blood lactate concentration. 

2.0 Review of Literature

2.1 Heart rate and Rock climbing

 Various studies have examined the effect of rock climbing on heart rate.

  Mace (1979) conducted a study to examine the psychological arousal in 44 female novice climbers and to see if preliminary training the responses could influence this arousal.  The subjects were split into two groups, with one group who received preliminary training and one controlled group who received no training. The groups were then asked to carry out a 70-foot abseil, during which the subjects' heart rate responses were measured. The study found that there was a significant increase in heart rate during the abseil, which was associated with fear or psychological stress. A greater increase was also found in the control group, than in the group who received preliminary training. The study however, did not use actual climbing, only an abseil and focused more on psychological than physiological stresses

Billat et al. (1995) investigated the aerobic capacity of competitive rock climbers and the specific energy demands of indoor rock climbing. The study used four elite male climbers. The protocol involved the subjects climbing two indoor routes, both graded French 7b (Fig. 1) and 15 m in length. Route one was more technically difficult, with smaller holds and containing 8 m of 90° overhanging climbing. Route 2 was less technical, with bigger holds, however was steeper throughout. The study found that heart rate increased significantly during the routes, with greater increases found in route one (85.5% of HR max.) than route 2 (77% of HR max.), which was attributed to the overhanging section in route one. However, Billat et al. (1995) only used four subjects. It is also not stated by the authors if a randomisation process was used during the climbing protocol.

Mermier et al. (1997) carried out research into the physiological responses to indoor climbing. The study involved 14 experienced climbers (9 male and 5 female) who climbed three routes of progressing difficulty. Route one graded 5.6 in the Yosemite Difficulty Scale (Figure. 1), was a 90° vertical wall; Route 2 was slightly overhanging (106°) and graded 5.9; Route 3 was 151° overhanging and graded 5.11+. The study found significant HR differences between the trials with post HR values of 142, 155 and 163 respectively. This corresponded to 74-85% of the subjects age predicted HR max, which was similar to the heart rate increases found by Billat et al. (1995). This suggests that indoor climbing is beneficial to aerobic fitness and that increased angle and difficulty lead to increased HR response. Heart rate response was not found to elicit a linear relationship with oxygen uptake (VO²) due to the use of upper body, isometric work.

Sheel et al. (2003) examined the relationship between indoor climbing and cycle ergonometry with the aim of quantifying the cardiovascular responses to indoor climbing. The climbing protocol involved 9 elite sport rock climbers (6 male, 3 female) performing two routes, classed as hard and easy. The routes were individualized and based on each climber's previous best climb.  On a separate occasion, the subjects' maximal oxygen uptakes were determined using cycle ergonometry. The study found that during the hard climb the subjects' heart rates were higher than during the easy climb, reaching 89% and 66% of cycling HR max respectively. The study again found a disproportionate increase in HR compared with V0², supporting previous research by Billat et al. (1995) and Mermier et al. (1997). As in Billat et al. (1995) only a small number of subjects were used

Janot et al. (2000) examined the heart rate differences between beginner and recreational climbers. Thirty-five subjects were used of whom 17 were recreational climbers and the rest non-climbers. The subjects carried out two indoor trials of increasing difficulty (Yosemite Difficulty Scale 5.6 and 5.9). The investigation found that the beginners had a higher pre-climb heart rate than the recreational group, which was attributed to higher levels of anxiety. During climbing, HR was found to be greater in the beginners (76-90% of HR max.) than in the recreational climbing group (71-79% of HR max.). The findings were attributed to the fact that the recreational climbers had more efficient climbing technique than the beginners had, who tended to rely more on their arms than the recreational group. The study, however, did not use a randomisation process during the climbing protocol, which may have affected the results of route two.

Booth et al. (1999) investigated the energy cost of sport rock climbing. The study used 7 high level male climbers. The subjects were assessed using an indoor vertical climbing treadmill, to determine their climbing specific V0² max. The subjects then carried out an outdoor rock climb, graded French 5c. The results showed that the route elicited a maximum heart rate of 190 beats.min and required a maximal oxygen uptake of 43.8 ml/kg/min. This was found to be 83% and 75% of the climbers V0² max and HR max respectively. Booth et al (1999) is the only study to date, which has examined climbers on actual rock. However, the sample size used was small and the study only looked at one route and not a variety of climbs. The outdoor climb was also carried out at an altitude of 890 m, which may have increased the HR response (Armstrong, 2000).

 2.2 Blood Lactate and Climbing

As well as examining heart rate changes in climbing, various studies have examined blood lactate changes to assess the physiological requirements of climbing.

Watts et al. (1996) investigated blood lactate changes in eleven elite male rock climbers. The protocol involved the subjects performing continuous laps on a pre-set indoor climbing route until failure. Blood lactate was monitored from fingertip blood samples, pre- climb, post- climb, and at 5, 10 and 20 minutes post climb. The post climbing blood lactate levels found ranged between 6.1 ± 1.4 mmol/l and remained at 2.3 ± 0.8 mmol/l after a 20 min recovery period. This significantly correlated with grip strength reduction (R=0.76) suggesting the blood lactate accumulation was related to fatigue in climbing. The increases in blood lactate levels to 6.1 mmol/l suggest a significant anaerobic contribution to energy production in climbing.

Watts and Drobish (1998) examined blood lactate responses during simulated climbing at different angles. The study used a climbing treadmill (Brewers Ledge tread-wall) to simulate climbing. The subjects, who were elite climbers, climbed to failure while climbing angle was gradually increased. Blood lactate was measure intravenously throughout the trial. It was found that blood lactate levels increased significantly at steeper angles and post- test blood lactate levels ranged from 4.9 to 5.9 mmol/l. However, the study only used simulated climbing, therefore, it is not known if this increase would be found in actual climbing.

Binney and Rolf (1999) examined blood lactate response in rock climbers using an indoor climbing ergometer. The aim was to investigate whether blood lactate accumulation during climbing was due to finger flexor fatigue, or whole body fatigue. The study used 15 experienced male climbers. The protocol involved the climbers performing repetitions of one double hand contraction of 5 s, followed by two 2 s single hand contractions, whilst their feet remained stationary. The process was repeated until failure at different angles (20°, 25° and 30° overhanging). The study found that mean blood lactate concentration was less than 2 mmol/l, with no significant increase found at different angles.  This suggests that the contribution of finger fatigue to blood lactate accumulation during climbing is minimal and that blood lactate is a significant indicator of fatigue in climbing.

Billat et al (1995) found post climb blood lactate levels of 5.7 mmol/l and 4.3 mmol/l during two indoor climbing routes, both graded French 7b. Route 1 was more technical with smaller holds and route 2 was steeper throughout with bigger holds. This suggests different physiological responses to routes of differing climbing style. However, the researchers have not specified which order the routes were climbed in, and whether a randomisation process was in place to avoid bias. The number of subjects used by Billat et al. (1995) was also small, with only 4 subjects used in the study.

Booth et al. (1999) found that blood lactate increased from 1.4 mmol/l to 10.2 mmol/l during an indoor climbing treadmill test to exhaustion. During an outdoor rock climb the subjects blood lactate levels increased from 1.3 mmol/l at rest to 4.5 mmol/l post climbing. This suggests that blood lactate response might be slightly lower for outdoor climbing, however as mentioned previously the study only used one climb, and as blood lactate response is influenced by steepness (Watts et al. 1998) and route style (Billat et al. 1995) during indoor climbing, this response may differ on different routes.

2.3 Grip strength and Rock climbing

 Various studies have measured grip strength whilst examining the physiological and anthropometrical characteristics of rock climbers. Grant et al. (1996) examined 30 male subjects, which included 10 elite rock climbers (>E1, see Figure one), 10 recreational climbers (> severe < E1) and 10 non- climbers. The study found that absolute grip strength did not differ greatly between the non-climbers and recreational group. However, the elite climbers had significantly greater grip strength, suggesting that high levels of grip strength are important when climbing routes of a difficulty of E1 (figure 1) and greater.  This differed to Watts et al (1993) who found only moderate grip strength levels in 21 male and 18 female, elite competition climbers, and suggested high levels of grip strength were not necessary for difficult climbing.

Mermier et al. (2000) investigated the physiological and anthropemetric determinants of sport climbing performance. The study examined 44 climbers of various levels of ability and experience.  The analysis showed relative grip strength to be a significant predictor of climbing performance, suggesting, like Grant et al. (1996) that by increasing grip strength, climbing performance can be improved.

Fewer studies have examined the influences of climbing on grip strength and the changes that occur from pre to post climbing. Watts et al. (1996) examined grip strength pre-climb, post climb and after 5, 10 and 20 minutes recovery, after climbing to exhaustion on an indoor route.  Handgrip was found to decrease by 22% post climbing. This was significantly correlated with climbing time (r=70), number of laps of the route completed (r=70) and post climb blood lactate levels (r=76). This suggests that grip strength is significantly reduced after climbing and supports the findings of Binney and Rolf (1999) that blood lactate is significantly related to this fatigue. Therefore, grip strength is a significant predictor of fatigue after rock climbing.

2.4 Rate of Perceived Exertion and Climbing

Only two studies have used RPE to measure work intensity in rock climbing. Janot et al. (2000) examined RPE differences between beginner and recreational climbers, who carried out two indoor climbing trials of increasing difficulty (YDS 5.6 and 5.9).  The study found that RPE values were significantly lower for the recreational climbers than for the beginners. Both groups were found to have higher post climb RPE values for the more difficult route 2 (14.4-15.1) than route 1 (11.5- 15.1).

Watts et al. (1998) examined RPE at different angles during a climbing treadmill (Brewer's Ledge Treadwall) exercise. The study found that RPE significantly increased as climbing angle increased (r = 0.986). Therefore, during steeper climbing RPE is significantly greater. However, this study was only carried out using simulated climbing and it is not known if this would be found during actual climbing.

 In conclusion, current research involving the physiological responses to rock climbing has found significant increases to HR (Mace, 1979; Billat et al., 1995; Mermier et al., 1997), BL (Watts et al., 1996; Watts and Drobish, 1998; Booth et al., 1999) and found grip strength to decrease significantly from pre to post climbing (Watts et al., 1996). Heart rate and BL response were found to increase with angle (Watts and Drobish, 1998), with HR also found to be influenced by route style (Mermier et al., 1997) and difficulty (Billat et al., 1995; Janot et al., 2000). Rate of perceived exertion has been found to be affected by climbing experience (Janot et al., 2000) and steepness (Watts and Drobish, 1998) but no study has compared RPE response during two different climbs of the same grade. However, research has focused mainly on sport climbing, choosing to ignore other disciplines of climbing (Watts, 2004). Research has mainly been carried out using indoor climbing walls (Billat et al., 1995; Mermier et al., (1997); Watts et al., 1996) and climbing treadmills (Watts and Drobish, 1998). Only Booth et al. (1999) has examined climbers in an outdoor setting; however only one route was used in the study, which, was located at an altitude of 890 m.

3.0 Methods

3.1 Subjects

 The subjects used were 6 experienced male rock climbers who had volunteered for the study. All the subjects had personal best lead climbs of E3 (French 6C+ / Yosemite. 5.11c) or greater and had al been climbing for a minimum of 5 years at the time of testing. No female subjects volunteered for the study, although previous research by Mermier et al. (1997) has found no significant differences between the physiological responses of male and female climbers. The subjects were aged 23.5 ± 2.59 years (figure 2). 

The subjects were screened prior to testing using the NEWI pre- test questionnaire to ensure that none of the subjects were suffering from any medical condition which might be affected during testing or affect the results of the testing. The subjects were also asked to fill in a climbing history questionnaire, designed by the researcher, to examine each subjects experience and ability and to ensure that each subject met the criteria mentioned previously. Each subject was informed about what was involved in the test and written consent was given by each. The subjects were asked not to take part in any vigorous activity for 48 hr prior to testing or eat or drink (except water) for 3 hr prior to testing (Booth et al., 1998). Each subject's height and mass was measured and the results are listed in Table 1.

Table 1: The subjects' mean ± SD age (years), height (cm) and mass (kg).

3.1 Protocol

 The investigation involved each subject climbing two outdoor rock climbs or routes.  . The location of the testing was Curbar edge in the peak district, Derbyshire, England. Two routes were selected by the researcher with the help of subjects, who were familiar with the area. Both routes were graded E1 5b (French 6a/b /Yosemite 5.10c), which was two grades below the least able subjects' on sight best. All of the subjects were familiar with both routes and had climbed them on at least one occasion previously. Both routes can be found in Selected Climbs on Peak Rock guidebook (see references for full reference) and the route descriptions are found below. Testing took place on the 11/04/04 and on the 06/05/04, with subjects 1, 2 and 3 tested on the first occasion and subjects 4, 5 and 6 tested on the second.

Route one was called Kayak E1 5b and was 8 m in length. The route was a technically difficult slab climb (approximately 80°) with a difficult move at half way, which involved a long stretch to a good handhold. The climb required good balance, with mainly the use of the feet for support.

Route two was called L'Horla, also E1 5b. The route was 9 m in length, so there was no significant difference in length with route 1. However, L'Horla was characterised with vertical start, which lead to a small overhang (approximately 115°). The route requires steep powerful climbing past the overhang using small holds. 

 Both routes were lead by the subjects in traditional style. This involved the first subject placing temporary protection or gear into the rock whilst climbing the route. The subject then clipped the rope, which was secured to his harness, into the gear to protect him in the event of a fall. The subject was belayed by a second subject from the ground using a standard belay device. When the first subject had finished climbing and been tested, the ropes were pulled back through the gear and the second subject climbed the route, clipping into the gear placed by the first subject. This was done to ensure that all of the subjects used the same amount of gear on each route. The process was repeated for the second route with a different subject placing the gear on lead. The process was randomised with subjects 1, 2, and 3 climbing route 1 first and subjects 2, 3 and 4 climbing route 2 first to avoid bias in the results. The subjects were also rotated, with no subject climbing both routes back to back, to avoid fatigue. 

Each subject used their own equipment (harness, ropes, rock boots and gear) and all equipment was checked thoroughly prior to testing by both the researcher and the subjects. Temperature and humidity was measured on both testing occasions to ensure that no significant differences to weather conditions were found between testing days.

3.3 Data collection

 Heart rate was monitored at 60 s intervals throughout each climb using the Polar Accurex plus HR monitor (model BG750 T778J, Polar Electro 0y, Finland). The data was recorded using the Polar Accurex plus wristwatch, which was attached to the subjects' wrist, and downloaded manually using EXCEL by the researcher. Recording was started immediately prior to climbing and was stopped as soon as each subject was safely over the top of the route.

 Blood lactate concentration was measured after each climb. In accordance with the methods used by Watts et al. (1996), Capillary blood samples were taken from the subjects' fingertips by the researcher within one minute of completing each route. The samples were then analysed immediately using the Accusport portable lactate analyser (model 1488767, Boehringer Mannheim, Germany). Further samples were not taken, as post-climbing blood lactate concentration has not been found to increase further throughout recovery (Watts et al., 1996). 

Grip strength was measured immediately before climbing and immediately after the post climbing blood lactate samples were taken using the Takei T.K.K. (model 5101, Takei scientific instruments co. LTD Japan) digital grip strength dynamometer. The dynamometer was adjusted for each subject so that the contact point of the handle reached the distal interphalangeal joint (Watts et al., 1996). Three trials were taken on each hand and the highest value for each was recorded. This was carried out before and after each route.

Prior to climbing, the subjects were introduced to the RPE (Borg's) scale by the researcher. Each subject's RPE was then measured immediately after each route in accordance with the methods used by Janot et al. (2000).

3.4 Data analysis

Data was entered into SPSS for statistical analysis. Pearson's bivariate correlations were used to examine the relationships between climbing time, mean HR, max HR, BL, grip strength changes and RPE on each route. Paired sample t-tests were used to locate significant differences between climbing time, mean HR, max HR, BL, grip strength changes and RPE for route 1 and climbing time, Mean HR, max HR, BL, grip strength changes and RPE for route 2 respectively. Statistical significance was set at p<0.05.

4.0 Results

Table 2: - The results of route 1 and route 2 are expressed as mean ± SD. The table also shows the differences between route 1 and route 2. * Indicates statistically significant differences (p<0.05).

  All of the subjects completed both routes without falling off. The data collected during and after route 1 and 2 is depicted in table 2. No significant differences in climbing time were found between route 1 and route 2 (Table 2). Heart rate was found to increase significantly during route 1 with significant differences found between pre climbing HR and HR max during the climb (p<0.05, t=0.000). Significant differences were also found between pre climbing HR and HR max during route 2 (p<0.05, t=0.00). Both max HR (p<0.05, p = 0.008) and mean HR (p<0.05, t=0.047) were found to be significantly greater during route 2 than during route 1. An example of the HR patterns over the two climbs can be seen in Figure 2.

  There were no significant differences found between the post climbing blood lactate concentrations after the two routes. Right and left hand grip strength was not found to decrease significantly after either route and no significant differences were found to grip strength changes after both routes. There were no significant differences found between RPE after route 1 and RPE after route 2. 

 There was found to be a significant relationship between max HR and RPE (p<0.05, r=0.816*) and between mean HR and RPE on route 2 (p<0.05, r=0.955**). No significant relationship was found between RPE and HR max or RPE and HR mean during route 1.  Heart rate max, but not HR mean, was significantly related to post climbing lactate concentration (p< 0.05, r=0.847*) after route 2 but not after route 1. Climbing time was not found to correlate significantly with max HR, mean HR or BL on either route but was found to be significantly related to RPE after route 1 (p<0.05, r=0.910*). Climbing time was also found to significantly relate to right, but not left, handgrip strength changes after route 2 (p<0.05, r=0.833*).

Figure 2:  Example of a typical HR trace taken from subject 3.

Figure 2: - Differences in HR max between route 1 and route 2 (p<0.05). Values are expressed as mean ± SD.

Figure 3: - Differences in mean HR between route 1 and route 2 (p<0.05). Values are expressed as mean ± SD.

5.0 Discussion

 As hypothesised, heart rate was found to increase significantly during both routes from pre climbing values. Heart rate was significantly greater during route 2 (Figures 2 and 3); despite both of the routes being graded the same (E1 5b).  This supports the findings of Watts and Drobish (1998) who found that heart rate increased in relation to increasing angle whilst climbing continuously on a climbing treadmill. Watts and Drobish (1998) also found that HR increased considerably when the angle of the treadmill reached 91°, which, was supported by the present study. Mermier et al. (1997) also found that heart rate was greater during a steeper climb, however the three routes used in their study were not graded the same; with the steeper route being graded the hardest. Therefore, in Mermier et al. (1997) it would be expected that the physiological demands would be greater in the steeper route.

 However the findings of this study conflict with the results of Billat et al. (1995), who found that heart rate was greater during a technically difficult route than during a steeper and more physical route when both routes were graded F7b. However, Billat et al. (1995) only used four subjects and it is not known whether the order in which they climbed the routes was randomised. The technically demanding route in Billat et al (1995) also contained 8 m of vertical climbing which may have placed some strain on the climbers arms, where as this the technical route used this study was a slab (<90°) throughout, requiring mainly the use of the legs for movement, with the arms required mainly for balance. Watts and Drobish (1998) suggest that heart rate increases significantly when climbing becomes vertical and beyond, as cardiac output is greater for a given work load during arm exercise than during leg exercise.  Therefore, a greater contrast in HR response would be expected between the two routes used in this study, than between the two used by Billat et al. (1995).

. Janot et al. (2000) also found greater HR values in beginner climbers in relation to recreational climbers, which they partially attributed to the greater use of the arms by beginners, where as the recreational climbers tended to use their feet more for support and movement. Therefore, the significantly greater HR found during the steeper route 2 could be caused by the increased use of the arms by the subjects during route 2. On route 1 the subjects relied more on their legs for support and movement than their arms.

 The routes used in this study were found to elicit HR responses of 71.6% and 83. 9% of the subjects' age predicted HR max, for route 1 and route 2 respectively. This supports the findings of Billat et al. (1995), who found HR responses of 77- 85.5% of HR max, and Mermier et al. (1997), who found HR responses of 74- 85% of HR max, during indoor climbing. This indicates that HR responses are similar during both indoor climbing and outdoor climbing and that HR is not sufficiently greater during lead climbing.   

  Grip strength was not found to decease significantly after either route, and for some of the subjects was actually found to increase from pre to post climbing. This differs from the findings of Watts et al. (1996) who found significant decreases to grip strength from pre to post climbing. However, one explanation for this is that in Watts et al. (1996) the subjects were asked to perform continuous laps of an indoor climbing wall until failure; Whereas, in the present study the subjects were climbing sub maximally, at a level at least two full grades below their best previous climb. Therefore, the routes used in this study may not have been sufficiently difficult, from a physical point of view, to induce the levels of fatigue found in the subjects in Watts et al. (1996). No significant differences between grip strength changes were found between the two routes, which suggest that grip strength is not influenced by steeper climbing. However, as previously mentioned the routes in this study may not have been relatively difficult enough to induce sufficient fatigue to impact upon grip strength performance of the subjects used in the study.

 Reductions to right, but not left, hand grip strength was found to be significantly related to climbing time during route 2. This suggests that the route may have required the use of the subjects' right hand more than the left. Another explanation could be that the subjects were all right handed; therefore, they may have used their right hand more than their left to hold on. However, no significant differences were found between left and right hand grip strength reductions on either route. Therefore, reductions to grip strength to the predominant hand may be dependant on the length time spent on the route during steep climbing.

 It was hypothesised that blood lactate concentration would be significantly greater after route 2 due to the steeper climbing. This was not found to be the case and the differences between the post lactate levels were not found to be significant (Table 2). However statistical significance was set at P<0.05 and the differences between the post lactate concentrations after route 1 and 2 was t=0.051. Therefore, with a larger sample size a statistically significant difference between the two routes may have been found. Watts and Drobish (1998) found that BL concentration increased significantly when climbing moved beyond vertical on the Brewers Ledge Treadwall. However, in the present study no significant differences in post exercise BL concentration were found between the slab climb and the steeper climb. However as previously mentioned, the routes in this study where considerably below some of the subjects maximum ability, so may not have been sufficiently difficult to cause significant increases to BL. Another limitation of the present study was that pre climbing BL concentration was not measured, due to difficulties faced by the researcher in getting the lactate equipment transported from the bottom to the top of the route in time to measure the subjects' BL immediately post climbing. Therefore, it is not known whether BL had increased significantly during from pre to post climbing on either route or if there were significant differences to pre and post lactate changes between the two routes. 

  The post climbing lactate concentrations found in this study, if accurate, indicate that rock climbing requires a significant contribution from anaerobic metabolism. Onset of blood lactate accumulation (OBLA) is characterised by an increase in BL past 4.0 mmols/l (McArdle et al., 2001). As the post climb lactate concentrations found in this study were 5.05 ± 1.01 mmol/l and 6.92 ± 1.43 mmol/l, for route 1 and route 2 respectively, both routes provided enough stimulation to reach this threshold. The post-climbing BL values in this study were similar to those found by Booth et al. (1999), who found post climbing values of 6.1 ± 1.4 mmols/l after an outdoor rock climb. The values were also typical of those found by Watts and Drobish (1998) who found post-climb lactate values ranging from 4.9 to 5.9 mmol/l, after the Brewers Ledge Treadwall test, depending upon climbing angle.

  This investigation found no significant relationship between post climbing BL and grip strength changes after either route 1 or route 2. This again conflicts with the findings of Watts et al. (1996), who found that post climbing BL was a significant predictor (r=76) of grip strength reductions that occurred from pre to post climbing. However, as mentioned the subjects in Watts et al. (1996) performed continuous laps until failure on an indoor wall and both significant increases in BL and significant decreases to grip strength were found. In the present study, the subjects did not climb to failure and no significant changes were found to occur to grip strength from pre to post climbing. Therefore, it is assumed that the subjects in Watts et al. (1996) were subjected to considerably greater physiological stimulation than the subjects used in this study. Another factor that may explain the differences found between Watts et al (1996) and this investigation is that, as mentioned in the present study BL was only measured post climb, and although elevated values (Table 2) were found after both routes, it is not known whether BL had increased significantly from pre climbing values.  

 Rate of perceived exertion was not, as hypothesised, significantly greater after route 2 than after route 1. This again conflicts with the research by Watts and Drobish (1998) who found RPE to increase in relation to climbing angle. The subjects' RPE values were found to be relatively low after both routes, supporting the researcher's assumption, that the routes used were not difficult enough to significantly exert the subjects physically. However, despite the researcher explaining to the subjects how to use the RPE scale it is possible that they did not use it correctly as none of the subjects were familiar with the scale prior to the testing. 

 Post climbing RPE was found to be a significant predictor of mean HR (p<0.05) and max HR (p<0.05) during route 2, which suggests that the RPE scale could be used in climbing to assess how hard a climber has exerted him or herself during climbing. However, the results of route 1 suggest otherwise, with no significant relationship found between RPE and mean HR, or RPE and max HR. This suggests that RPE is only a significant predictor of exertion, in routes that are steep and strenuous in nature, where as in slab climbs, which require more balance and technique, RPE may not be an accurate way to measure physical exertion. Further research should examine the validity of the RPE scale during climbing as no previous research has examined this. Another limitation of this study was that RPE was only measured post climb, due to the logistical difficulties. Lead climbing also requires high levels of concentration on the part of the climber due to the serious risks involved. However, research could be carried out with climbers on a top rope to examine the use of the RPE scale throughout a climb.

No significant differences were found between climbing time during the two routes (Table 2). Climbing time was not found to relate to mean HR or max HR on either route, which suggests that the significant differences found in HR between the routes were related to the increased upper body work required during route 2 (Watts and Drobish, 1998). However, climbing time was significantly related to RPE after route 1 but not after route 2. As mentioned previously, RPE was significantly related to mean HR and max HR during route 2, but not during route 1, which again questions the validity of using the RPE on climbers.

6.0 Conclusion

 This study found that heart rate was increased significantly during climbing. Heart rate was also found to be significantly greater during climbing steeper routes, in relation to climbing slabs when both routes were of the same level of difficulty; as indicated by the UK grading system. Therefore, this investigation supports the findings of Watts and Drobish (1998) who found HR to increase significantly when the angle of the climb reached 91°. During Outdoor, lead, rock climbing, max HR was found to correspond to 71.6% and 83.9% of HR max, for route 1 and route 2 respectively; which supports the findings of Billat et al. (1995) and Mermier et al. (1997). This suggests that there were no significant differences to physiological responses between indoor and outdoor climbing

  However, unlike in Watts in Drobish (1998) no significant differences to post climbing blood lactate concentration were found after the two types of climb. Rate of perceived exertion was not found to be significantly greater after steep climbing and no significant differences were found to occur between pre and post grip strength. Grip strength was not influenced by the steepness of the climb and, unlike in Watts et al. (1996), grip strength changes were not related to post climbing blood lactate concentration. Rate of perceived exertion was found to be a significant predictor of max HR and mean HR during route 2 but not during the route 1.

6.1 Limitations

 There were various limitations of this study. Firstly, a small sample size was used, with only 6 subjects involved in the testing. As with most research involved in rock climbing, the subjects were high-level male climbers, therefore the results of this investigation should be applied only to this population. The study looked specifically at two particular types of climb, a slab and an overhang, both of which were less than 10 m in length; therefore, the researcher choose to ignore all other types of route, corners, cracks, roofs, arêtes etc. The findings should not, therefore be applied generically to rock climbing, but specifically to short, middle grade, traditional climbs, carried out on Gritstone, which are similar in style to the routes used in this study.  Further limitations of the study were that BL was not measured before climbing, heart rate was only sampled at 60 s intervals and RPE was only measured post climb; all of which may have affected the accuracy of the results of this investigation.

6.2 Recommendations for further research

 More research needs to examine the physiological responses of climbing different types of routes and on different types of rock. The findings of this study suggest that the physiological requirements of climbing are significantly different even during climbing two routes of similar length and grade. More in depth research should focus on the differences between indoor and outdoor climbing; although no significant differences were found in HR response between the outdoor climbing in this study and in previous research carried out indoors, differences in subjects and methodologies mean it is not possible to make a direct comparison between the two. Therefore, future studies should compare responses to indoor and outdoor climbing using the same subjects. Future research should examine the validity of using the RPE scale within climbing. The findings of this study suggest that RPE may be a significant indicator of HR response during steep climbing but not during slab climbing. 

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