Few studies have quantified resting mouse muscle metabolism and even fewer studies have separated the contribution of sarcoplasmic reticulum (SR) Ca2+ pumping to resting metabolic rate. Furthermore, the studies that have attempted to quantify the contribution of Ca2+ pumping have used indirect methods to inhibit SR Ca2+ ATPase activity. The purpose of this study is to directly quantify resting muscle oxygen consumption and the contribution of SR Ca2+ pumping to resting oxygen consumption in mouse hindlimb muscles by using CPA to specifically inhibit Ca2+ pump activity in intact muscles at rest. The TIOX system was used to measure resting muscle VO2 of extensor digitorum longus (EDL) and soleus (SOL) muscles at 30oC and 20oC. C57BL mice aged 8-12 weeks were used with an average whole body mass of 23.8 g and EDL and SOL dry weights averaging 1.88 mg and 1.8 mg, respectively. All muscle VO2 measurements are expressed per gram dry weight. There were no differences (P>0.1) in resting muscle VO2 between EDL and SOL muscles at either 30oC (EDL, 2.05 µL/g/s; SOL, 2.27 µL/g/s) or 20oC (EDL, 0.62 µL/g/s; SOL, 0.71 µL/g/s). The average Q10 (3.1) was determined from EDL and SOL VO2 measures at 20oC and 30oC. The contribution of Ca2+ pumping by the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) was measured at 30oC using a range of CPA concentrations (1-15 µM) . There was a concentration-dependent effect of CPA on oxygen consumption with increasing CPA concentrations up to 10 µM resulting in progressively greater reductions in muscle oxygen consumption. Specifically, 1, 5, 10, and 15 µM CPA caused an 11, 35.4, 49.5, and 50.3% reduction in VO2. There were no differences (P>0.1) between 10 and 15 µM CPA indicating that 10 µM CPA induces maximal inhibition of SERCA in isolated muscle preparations. The results indicate that the Ca2+ pumping by SERCA is responsible for ~50% of oxygen consumption in resting mouse EDL and SOL muscle. This is the first study to use a direct inhibitor of SERCA to quantify the contribution of Ca2+ cycling to resting oxygen consumption and therefore is a more accurate reflection of the actual contribution of SERCA to resting muscle oxygen consumption compared to previous findings. These results suggest that SERCA energy consumption accounts for a large portion of resting muscle metabolism and may represent a potential therapeutic target for metabolic alterations to oppose obesity.

‘Animal personality’ refers to individual behavioural differences that are consistent over time and context. Physiological constraints are suggested to underlie this constraint in behavioural plasticity. As energy is required for physiological processes that generate behaviour, energy metabolism could be a proximate explanation for personality. Currently, the most coherent framework linking behaviour, metabolism and life history-traits is still poorly tested empirically, and studies are showing contradicting results. Therefore, I here aim to explore this relationship further by investigating the relationship between basal metabolic rate (BMR) and personality in Red Junglefowl (Gallus gallus). Birds used had known responses in personality assays, and their metabolic rates were measured by determining oxygen consumption in standardized conditions throughout the night using an open respirometry system. BMR was negatively correlated with time spent foraging, and positively correlated with time spent being vigilant. Considering foraging an ‘activity’ (due to its energy-demand), my results support the allocation model, a model that assumes that an animal has a fixed amount of energy, thus that an energetic trade-off occur between competing energy requiring processes such as BMR and activity. Hence, an animal with low BMR has more energy to spend on activity. However, I do not consider vigilance as an energy-demanding activity; hence this relationship cannot be interpreted in this framework. Taken together, my results show a relationship between personality and BMR, although their relationship still needs further investigation to understand the causality and consequences of it.

Few studies have quantified resting mouse muscle metabolism and even fewer studies have separated the contribution of sarcoplasmic reticulum (SR) Ca2+ pumping to resting metabolic rate. Furthermore, the studies that have attempted to quantify the contribution of Ca2+ pumping have used indirect methods to inhibit SR Ca2+ ATPase activity. The purpose of this study is to directly quantify resting muscle oxygen consumption and the contribution of SR Ca2+ pumping to resting oxygen consumption in mouse hindlimb muscles by using CPA to specifically inhibit Ca2+ pump activity in intact muscles at rest. The TIOX system was used to measure resting muscle VO2 of extensor digitorum longus (EDL) and soleus (SOL) muscles at 30oC and 20oC. C57BL mice aged 8-12 weeks were used with an average whole body mass of 23.8 g and EDL and SOL dry weights averaging 1.88 mg and 1.8 mg, respectively. All muscle VO2 measurements are expressed per gram dry weight. There were no differences (P>0.1) in resting muscle VO2 between EDL and SOL muscles at either 30oC (EDL, 2.05 µL/g/s; SOL, 2.27 µL/g/s) or 20oC (EDL, 0.62 µL/g/s; SOL, 0.71 µL/g/s). The average Q10 (3.1) was determined from EDL and SOL VO2 measures at 20oC and 30oC. The contribution of Ca2+ pumping by the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) was measured at 30oC using a range of CPA concentrations (1-15 µM) . There was a concentration-dependent effect of CPA on oxygen consumption with increasing CPA concentrations up to 10 µM resulting in progressively greater reductions in muscle oxygen consumption. Specifically, 1, 5, 10, and 15 µM CPA caused an 11, 35.4, 49.5, and 50.3% reduction in VO2. There were no differences (P>0.1) between 10 and 15 µM CPA indicating that 10 µM CPA induces maximal inhibition of SERCA in isolated muscle preparations. The results indicate that the Ca2+ pumping by SERCA is responsible for ~50% of oxygen consumption in resting mouse EDL and SOL muscle. This is the first study to use a direct inhibitor of SERCA to quantify the contribution of Ca2+ cycling to resting oxygen consumption and therefore is a more accurate reflection of the actual contribution of SERCA to resting muscle oxygen consumption compared to previous findings. These results suggest that SERCA energy consumption accounts for a large portion of resting muscle metabolism and may represent a potential therapeutic target for metabolic alterations to oppose obesity.

No abstract available.

Although artificially selected goldfish exhibit swimming performance decrements, with the most derived morphotypes more affected, they can be utilized to explore functional design and movement pattern principles in aquatic vertebrates. Drag, steady swimming kinematics (tailbeat frequency, amplitude, stride length), energetics (standard and active metabolic rate), fast-start performance (average and maximum velocity and acceleration), stability in yaw and roll and propulsive muscle ultrastructural characteristics (mitochondrial volume density and spacing, myofibril diameter and capillary to fibre ratio in red and white muscle) were measured for four morphotypes: common, comet, fantail and eggfish, of comparable length (≈ 5 cm). A performance “pairing” (common and comet; fantail and eggfish) was a recurrent theme for most performance parameters. Vertebral numbers (30), segment lengths (≈ 0.85 mm) and standard metabolic rates (≈ 140 mg O2 kg-1 hr-1) are exceptions where values are the same. Fantail and eggfish drag and drag coefficients (referenced to frontally projected area ≈ 0.6 - 0.9) were higher (requiring more thrust at any given velocity) than those for the more streamlined common and comet (≈ 0.3 - 0.6; P < 0.05). This is reflected in kinematics; tailbeat frequency and stride length at any given velocity for the common and comet are lower and higher respectively than that of the fantail and eggfish (P < 0.05). Common and comet fatigue times are not significantly different from that of their ancestor, Crucian carp (P > 0.05), and are lower than those of the fantail and eggfish (P < 0.05). The cost of transport of the common and comet (≈ 0.6 mg O2 kg-1 m-1) is accurately predicted from the mass scaling relationship for fish (P > 0.05), but values for the fantail and eggfish (≈ 1.3 mg O2 kg-1 m-1) are not (P < 0.05). Eggfish steady swimming (dorsal fin absent) was characterized by rolling and yawing motions associated with significant energy losses. Common and comet fast-start performance (average velocity ≈ 0.45 m s-1, maximum velocity ≈ 1.2 m s-1, average acceleration ≈ 7.5 m s-2, maximum acceleration ≈ 35 m s-2) was similar to that of other locomotor generalists (e.g. trout). Eggfish maximum acceleration (≈ 5 m s-2) is poor due to the absence of inertial and lifting contributions to thrust from the dorsal fin and energy wasting rolling motions. Artificially selected fish can bear upon fitness related adaptations associated with form and movement, providing insights into the “performance envelope” of natural systems subject to ecological speciation.

Aim The overall aim of this study was to develop a broader understanding on how to optimize the organization of aerobic endurance training programs, and especially how to better organize high-intensity training (HIT) and low intensity training (LIT) to give an optimum endurance performance progress. Method This study compared the effects of two different training organization methods in trained cross-country (XC) skiers and biathletes. During a 5 week intervention period, one group of athletes (n = 10, 7 men and 3 women, age 23 ± 9 years) performed block periodization (BP) training with 5-1-3-1-1 HIT sessions in the respective weeks. The other group of athletes(n = 9, 7 men and 2 women, age 22 ± 5) followed a more traditional periodization (TRAD) method performing 2-2-3-2-2 HIT sessions. LIT was interspersed between the HIT sessions so that both groups performed similar total volumes of HIT and LIT during the intervention period. Results The BP group increased relative and absolute VO2max (2.6 ± 3.6% and 2.0 ± 2.5%, P &lt; 0.05) and time to exhaustion (6.1 ± 6.4%, P &lt; 0.01). No changes were seen in the TRAD group on relative or absolute VO2max (0.8 ± 3.5% and -0.1 ± 3.0%) or time to exhaustion (-2.0 ± 7.7%). Mean effects size (ES) of the relative and absolute improvement in VO2max and time to exhaustion revealed small to moderate effects of performing BP training vs. TRAD training (ES range from 0.51 to 1.14). Conclusions This study indicates that organizing endurance training in XC skiers with block periodization training give better adaptations compared to performing traditional periodization training during a 5 week training period when performing similar volumes of high-intensity and low intensity training.

Sammanfattning Syfte och frågeställningar. Syftet med denna studie var att på äldre personer studera olika fysiologiska parametrar före och efter en period på åtta veckor med styrketräning som utförs tre gånger i veckan. Frågeställningarna var: Hur påverkas statisk och dynamisk maximal styrka i främre lårmuskulaturen av styrketräning? Är det någon skillnad i resultat mellan koncentrisk och excentrisk styrka i lårmuskulaturen före och efter styrketräningsperioden? Är det någon skillnad i förändring mellan benstyrka uppmätt med isokinetisk teknik jämfört med uthållighetsstyrka och ett kort funktionellt benstyrketest? Hur påverkas maximal syreupptagningsförmåga registrerad via submaximalt cykeltest respektive vid pyramidtestet av träningsperioden? Metod. I studien deltog 20 generellt ej påtagligt aktiva män och kvinnor i åldrarna 66-79 år. Av dessa var 11 individer slumpvis indelade i en styrketräningsgrupp och övriga nio utgjorde en inaktiv kontrollgrupp. Ett flertal olika fysiologiska tester, som bl.a. prövade testpersonernas styrka samt kondition, utfördes innan och efter träningsperioden. De deltagare som utgjorde träningsgruppen tränades i relativt tung styrketräning i åtta veckor. Resultat. Undersökningen resulterade i en signifikant ökad koncentrisk-, excentrisk- samt statisk momentan benstyrka för träningsgruppen efter de åtta veckorna med relativt tung styrketräning. Vidare kunde även utläsas för dem en signifikant förbättring av uthållighetsstyrka i benen (hastighet vid 50 uppresningar från stol, med 16,9 %) samt vid ett kort funktionellt test (5 uppresningar från stol, med 12,8 %). De träningsgenererade signifikanta ökningarna för träningsgruppen tyder inte på några stora procentuella skillnader mellan statisk (10,4 %) och dynamisk excentrisk (7,8 %) eller koncentrisk maximal styrka (9,5 %). Vid testerna cykelergometertest (kondition), effekt i 5-minuterspyramidtest (ett modifierat steptest) samt distans vid 6-minuters gångtest framkom inga signifikanta förbättringar för träningsgruppen. Ingen i kontrollgruppen visade en signifikant förbättring i någon av de nämnda testerna. Slutsats. Studien visar att interventioner, med åtta veckors intensiv styrketräning, tre gånger per vecka för äldre kvinnor och män, påtagligt kan förbättra resultaten vid styrkemätningar såväl momentant som uthållighetsmässigt och vid ett kort funktionellt test, medan tester av maximal syreupptagningsförmåga (VO2max) inte förbättras. Emellertid framkom i cykelergometertestet en tendens till förbättring för träningsgruppen.

The purpose of this study was to develop an incremental field exercise test of disability to use in the assessment of functional capacity in patients with chronic airways limitation (CAL). The test was modified from the 20m shuttle running test, employed to predict the maximal oxygen uptake of sporting individuals. The protocol devised for the patients was adapted from the running speeds proposed by Leger and Lambert (1982). The shuttle walking test requires patients to walk up and down a 10m course at speeds dictated by a series of audio signals played from a tape cassette, increasing each minute to a symptom limited maximum performance. Examination of the reproducibility of the test revealed strong test/retest reliability, after just one practice walk. The mean between trial difference (test 2 vs test 3) was -2m,(n=10), (95% CI -21.9 to 17.9m). The shuttle walking test was validated against the traditional measurement of peak oxygen uptake (Vo2pmk) measured conventionally during an incremental maximal treadmill test with Douglas bags (n=19). The results from this exercise test were compared against the patients' performance (distance achieved) on the shuttle walking test (after one practice walk) and revealed a strong relationship between the two variables (r=0.88). The validity and the resistance to breathing, of a portable oxygen consumption meter was examined. Validation, again in comparison to Douglas bag measurements, involved four cohorts (two healthy and two patient groups). After some modifications to the equipment, measurements of lib2 by the two different methods were not significantly different. The patients' response to the shuttle walking test was examined (n=10). The heart rate, ventilation and 7Orck2 increased gradually in response to the increasing intensity of the shuttle walking test. Again Vo 2wa measurements related strongly to the patients performance (r=0.81). A further study employing a treadmill test and shuttle walking test confirmed that the latter provided a comparable metabolic and physiological challenge to the patients as the conventional treadmill test. Comparison with the 6 minute walking test (6MWT), one of the most commonly employed field exercise tests in this patient population) revealed that the heart rate response was significantly higher in the shuttle walking test than the 6 MWT and graded, a response not observed in the 6MWT. The shuttle test reflected the true extent of the patients disability more accurately than the 6MWT. The shuttle walking test provides a simple, reproducible exercise test of disability in patients with CAL that relates well to Vb2puk . The external pacing of the test allows more valid intra- and inter- subject comparison than has previously been possible with field tests alone.

The five discrete, but related studies presented in this thesis investigate several aspects of the physiology and biochemistry of whole animals, perfused and isolated tissues from fishes and other vertebrates. Important fundamental questions about tissue metabolism and energy supply and utilisation in relation to oxygen supply, in addition to applied questions relating to commercial harvesting and post-mortem muscle physiology were addressed. Oxyconformance of oxygen consumption (VO2) at low oxygen delivery rates was shown using an isolated, perfused salmon tail preparation, composed primarily of skeletal muscle. Addition of pig red blood cells to the perfusing solution at a haematocrit of 5 or 10%, increasing the capacitance, resulted in oxyregulation of VO2 by the tail tissues. Below c.60 ml O2.kg-1.h-1 of oxygen delivery, VO2 was delivery dependent. Above this value additional oxygen delivery did not increase VO2 of resting muscle above c.35 ml O2 kg-1.h-1. The preparation was validated by measuring mitochondrial activity using MTT and blood flow distribution to the red and white muscle using fluorescent microspheres. Evidence of both O2-independence of VO2 in the vasculature and strict O2-dependence of VO2 in striated muscles of fishes and a mammal is presented using isolated vascular tissue and an in vitro tissue slice model. VO2 by vessels from rat, salmon and hagfish showed varying degrees of independence between PO2s of 15-95 mmHg in vitro (1 mmHg = 0.133 kPa). Above and below these values, VO2 was highly PO2-dependent. VO2 by cardiac and skeletal muscles from rat, salmon, snapper and hagfish were shown to relate linearly to PO2 between zero and 125 mmHg. VO2 in these tissues was highly dependent on tissue type (cardiac, red and white muscle) which correlated with haem protein concentration. The increase in VO2 in muscle slice mitochondria uncoupled with FCCP and DNP ruled out diffusion-limitation as a constraint on VO2. Mitochondrial activity was constant over time and reoxygenation of the Ringer bathing the tissues after the initial run down in PO2 resulted in VO2 rates that were unchanged from the starting values, demonstrating that the tissues remained viable over time. ATP turnover in red muscle was significantly increased at 100 mmHg relative to 30 mmHg, and increased in both treatments from values at the start. Our data suggest that ATP supply and ATP demand were reduced in conjunction with falling PO2. The effects of hydrogen sulphide (H2S) (derived from Na2S) and isoeugenol exposure on activity, VO2 and ventilation frequency (Vf) in a teleost fish are reported. In the H2S treatment group (200 μM Na2S) both resting VO2 and Vf decreased after 30 minutes of exposure, concurrent with narcosis and a loss of equilibrium. These events corresponded with a significant fall in VO2 (33%) and Vf (20%) by 15 minutes, both declining further to a nadir of 40% of resting values at 30 minutes. After flushing, VO2 increased to resting levels, with Vf remaining significantly depressed until 30 minutes of recovery. Recovery was accompanied by regained mobility and equilibrium and significantly increased VO2 and Vf. Isoeugenol anaesthetised fish (0.011 g.L-1) reached stage 4-5 of anaesthesia accompanied by significant decreases in VO2 (45%) and Vf (25%) at 25 minutes, both parameters declining further to around 64% and 38% respectively by 35 minutes. Similar to H2S exposed fish, VO2 increased to resting values after flushing, followed by a significant rise in VO2. Likewise, Vf had risen to resting values post-flushing, subsequently increasing significantly during recovery. Overall, VO2 in relation to resting rate was reduced in the isoeugenol treated animals, while in H2S treated fish, exposure there was increased oxygen usage, possibly associated with a toxic effect. H2S significantly reduced cytochrome c oxidase activity in muscle and gill tissue in vitro between 69-79% at 20 μM and 77-97% at 200 μM Na2S, while isoeugenol had no effect on activity in any tissue. Calorimetric and biochemical profiles of anoxic, post-mortem white muscle from Chinook salmon subjected to rested and exhausted harvesting regimens at their acclimation temperature (10°C) are reported. Prior to harvest rested animals were anaesthetised with 0.012 g.L-1 isoeugenol without disturbance. The muscle of these animals had a high metabolic rate at the time of death, at around 400 μW.g-1, which declined rapidly over the first 12 hours to15 μW.g-1. Exhausted animals were forced to swim and were crowded before capture, resulting in an initial heat output of <10 μW.g-1. Heat output was significantly greater in the rested group at the time of death and for 7 hours post-mortem. In both groups there was an exothermic event, occurring between 4 and 6 hours post-mortem amounting to a rise of around 35 μW.g-1. A one-phase exponential decay model appropriately described the net heat output of the rested profile minus the exhausted data. Rested animals had significantly higher initial cut surface pH (7.5 vs 6.7), tissue glycogen (16 vs 2 μmol.g-1), creatine phosphate (18 vs 0.1 μmol.g-1), ATP (6 vs 3.5 μmol.g-1) and potential energy (30 vs 7 μmol.g-1) than the exhausted group, which had significantly elevated tissue concentrations of lactate (43 vs 18 μmol.g-1) and glucose (5 vs 2 μmol.g-1). Potential energy in the form of ATP, glycogen and creatine phosphate remained elevated for an extended period post-mortem in rested animals while catabolites further down the chain such as inosine, hypoxanthine and uric acid accumulated at similar rates in both groups. We examined the relationship between exogenous and endogenous H2S and oxygen partial pressure in isolated hagfish and lamprey vessels that exhibit profound hypoxic vasoconstriction (HVC). In myography studies, H2S (Na2S) dose-dependently constricted dorsal aortas (DA) and efferent branchial arteries but did not affect ventral aortas or afferent branchial arteries, which was similar to the effects produced by hypoxia. Sensitivity of H2S-mediated contraction in hagfish and lamprey DA was enhanced by hypoxia. HVC in hagfish DA was enhanced by the H2S precursor cysteine and inhibited by amino-oxyacetate (AOA), an inhibitor of the H2S-synthesising enzyme, cystathionine β-synthase, and unaffected by propargyl glycine, an inhibitor of cystathionine λ-lyase. Oxygen consumption (MO2) of hagfish DA was constant between a PO2 of 15 and 115•mmHg, decreased when PO2 <15•mmHg, and increased if PO2 exceeded 115•mmHg. 10 μmol.l-1 H2S increased and concentrations above 100 μmol.l-1 H2S decreased MO2. Consistent with the effects on HVC, cysteine increased and AOA and hydroxylamine, an inhibitor of pyridoxyl 5’-phosphate-dependent enzymes, decreased MO2. These data show that H2S is a monophasic vasoconstrictor of specific cyclostome vessels and because hagfish lack vascular NO, and vascular sensitivity to H2S was enhanced at low PO2, it is unlikely that H2S contractions are mediated by either an H2S-NO interaction or an oxidation product of H2S. These experiments provide additional support for the hypothesis that the metabolism of H2S is involved in oxygen sensing/signal transduction in vertebrate vascular smooth muscle. Together the findings of this thesis contribute to the understanding of oxygen utilisation and energetics in relation to oxygen supply in a number of tissues. These data further our understanding of respiratory physiology and may have practical applications in the seafood industry.

Rock climbing is thought to rely upon the interaction of various performance components, and has previously been described as a complex multi-faceted sport. It has been suggested that psychological aspects of performance, such as task perception and the interaction of resulting pre-climb anxieties, contribute greatly to the physiological responses and the overall performance during ascent. However, research which seeks to investigate both psychological and physiological responses during specific bouts of rock climbing are few in number. This thesis attempts to contribute to the novel yet limited body of field based psychophysological research relating to rock climbing. To this end, the studies contained within this thesis investigated psychological and physiological responses as a result of difficult on-sight rock climbing. Elaborating upon previous research, additonal factors which are thought to influence these responses were explored. More specifically, differences in responses between ability groups, style of ascent, and route type were investigated. In study one, differences in psychological and physiological responses with respect to ability level and ascent style were investigated, during a single on-sight ascent. Seventy-two climbers were split into ability groups defined as lower-grade, intermediate, advanced and elite based on self-reported on-sight grades (Ewbank) of ≤17, 18-20, 21-24 and ≥ 25 respectively. Each climber attempted an on-sight ascent of a designated test route set on an indoor artificial climbing wall. A separate test route was set for each ability group which targeted their self-reported ability with respect to best on-sight. Participants were randomly assigned to either a lead or top-rope ascent and climbers were not informed of their style of ascent until 15 min prior to climbing. Responses to the climbing task were measured pre, during, and post-climb using a number of psychological and physiological markers. In total fifty-two participants successfully completed their on-sight ascents, and data for successful ascents were analysed and compared. Pre-climb variables were considered together in order to investigate pre-climb state, more specifically levels of anxiety, prior to ascent. Results indicated that there were no significant differences for grouped pre-climb variables with respect to ascent style. These results suggest that irrespective of ascent style, successful climbers exhibited similar psychophysiological responses prior to attempting an on-sight ascent. Furthermore, this trend was replicated across all ability groups. These findings were thought to be indicative of the high demand and level of uncerainty imposed by the on-sight condition of ascent, lending support to previous suggestion that an on-sight ascent induces the highest anxiety response. During the climb, HR and were measured and averaged across the entirety of the ascent. When expressed as a percentage of and the average HR and responses during ascent were found to be comparable across ability groups. As such, all ability groups appeared to utilise similar fractions of maximal capacity, with elite climbers successfully ascending a route up to eight difficulty grades harder than those of lower ability, whilst still performing at the same workload intensity. It would appear that oxygen uptake during rock climbing may not be directly related to difficulty or personal ability. A technical advantage, personal climbing style, and possible physiological adaptations may be contributors to more strategic and efficient ascents resulting in the capacity to climb at higher grades of difficulty. The second study presented within this thesis was comprised of two phases of investigation; (1) to investigate whether psychological and physiological responses to competition-style climbing differed with respect to ability level, and (2) to investigate potential psychological and physiological differences based on route type and outcome (success and failure). In phase 1 of study two, intermediate, advanced and elite climbers attempted an lead on-sight ascent of a competition-style route which increased in difficulty as the climber progressed. The route was set with the intention of being just beyond the upper limits of the elite climbers self-reported best on-sight ability (~26 Ewbank). This was done in order to ensure that a fall from the route was highly likely, even for the elite climbers. All climbers failed to successfuly ascend the test route and as such all climbed to the point of failure resulting in a fall. The results obtained both prior to, and during ascent suggest that the intermediate and advanced climbers in the current study may have been limited by technical ability as opposed to physical exhaustion, or increased levels of anxiety. Elite climbers were to be able to maintain a more sustained physical effort during the more difficult phases of the climb. This appeared to be reflected in post-climb blood lactate concentration and ratings of task demand with respect to both physical demand and effort. As such it may be that elite climbers are more accustomed to maximal effort and demonstrate an increased tolerance to the higher exercise intensity required during more difficult ascents. In the second phase of study two the psychological and physiological responses of climbers in a competitive setting obtained in phase 1, were compared with those exhibited by participants during both successful and unsuccessful lead on-sight ascents in study one. The aim of study two phase 2 was to determine whether the responses of successful climbers differed from those who succeeded by reaching the top of a route, and performances in a competitive context where success is denoted by the distance achieved by a climbers on their ascent. The main findings in this instance were that although there were no significant differences observed between categories of ascent (successful, unsuccessful and competition) for grouped pre-climb variables, trends in CSAI-2R responses indicated high cognitive anxiety coupled with lower self-confidence prior to unsuccessful ascents. As such it may be that self-confidence acts as a buffer in moderating success in rock climbing, demonstrating the role of positive emotions and their impact upon performance as opposed to the detrimental effect of the negative. A second finding of this study was that there appeared to be a differing HR- relationship based on ascent category. Modest increases in were shown for all ascents, irrespective of ability level. A plateau in response was accompanied by a similar plateau in HR response during successful ascents, yet HR was shown to increase in a linear fashion until point of failure during unsuccessful ascents. It is possible that these findings highlight the presence of a climbing specific limitation.