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Physiological requirements for world-class performances in endurance running
... Par le passé, les variables comme la VO2max ou la puissance maximale aérobie ont clairement été investies afin de comprendre leurs impacts sur la performance de course (344)(345)(346)(347) Ces auteurs, avec ces prédictions améliorées par les modèles non linéaires, se rapprochent, mais sans le décrire ou l'énoncer, de la notion de poids optimal (figure 24). ...
The purpose of this thesis is to study the morphological changes of top athletes and identify structural links between performance and anthropometric characteristics.
This thesis is comprised of various studies that analyze the highest level of performance by morphological aspect and different levels of proof. At first, we show differentiated changes between high level athletes and individuals in the general population (Studies 1 and 2), presupposing that athletes draw benefits from their anthropometric characteristics. Then we highlight the direct links between anthropometric characteristics and performance in track and field athletes and rugby players (studies 2 and 5): rugby teams with heavier forwards and taller backs are more successful than others. In track and field, calculated allometric coefficients show the impact of mass depending on the distance of the race and sex, suggesting a possible anthropometric progression margin for female athletes. The third level of supporting evidence, highlights the existence of couples [optimal morphologies - optimal performance], biometric attractors beneficial in scoring in basketball (Study 3), and BMI optimum with performance intervals in race distance (studies 4, 5 and 6). Mass, height and BMI are relevant indicators used to specify athletes between different events (morphological gradients in track and field following the spectrum of distances, like energy gradients) but also according to their level (inverse gradient between mass and height according to middle and long distances and sprints). These three indicators also reveal morphological differentiation depending on the specific position. Comparing the two, changes in mass and height show asynchronous growth indicative of atypicity. Independent from BMI’s primary function of measuring body size and obesity, it should be refined as a useful indicator of high level performance. Indeed, it reveals trade-offs between power, energy capacity and organization of efficient body structure for high level athletes. In athletic performance, the whole body is in action, and mass, height and BMI take into account the entire athlete who moves. The findings of this thesis will assist in making conclusions and new ways to understand performance and will assist to generate the development of experimental protocols. Physiques are the expression of the performance as well as the organization from which it is realized. The results of this thesis, based on the analysis of consistent databases, provide a new vision on morphological optimizations. For the purpose of performance, it is necessary to know the optimizations established in order to situate athletes in their morphological fields, but also enable them to move towards better anthropometric adaptation specific to their activities.
... In these studies (Nordby et al., 2006;Stisen et al., 2006), subjects with high and low VO 2 max values were compared, assuming that the higher VO 2 max values represented the more trained subjects. However, even if the VO 2 max is used frequently as a physiological parameter to discriminate the aerobic fitness (Costill et al., 1973;Wyndham et al., 1969), there are some studies that have indicated it may have limited power in predicting the endurance performance (Morgan et al., 1989;Noakes et al., 1990). This limited predictive power could be due to a complex interplay between other physiological factors beyond the VO 2 max and the endurance performance (Weston et al. 1999). ...
This study aimed to compare maximal fat oxidation rate parame-ters between moderate- and low-performance runners. Eighteen runners performed an incremental treadmill test to estimate individual maximal fat oxidation rate (Fatmax) based on gases measures and a 10,000-m run on a track. The subjects were then divided into a low and moderate performance group using two different criteria: 10,000-m time and VO2max values. When groups were divided using 10,000-m time, there was no signifi-cant difference in Fatmax (0.41 ± 0.16 and 0.27 ± 0.12 g.min-1, p = 0.07) or in the exercise intensity that elicited Fatmax (59.9 ± 16.5 and 68.7 ± 10.3% O2max, p = 0.23) between the moder-ate and low performance groups, respectively (p > 0.05). When groups were divided using VO2max values, Fatmax was signifi-cantly lower in the low VO2max group than in the high VO2max group (0.29 ± 0.10 and 0.47 ± 0.17 g.min-1, respectively, p < 0.05) but the intensity that elicited Fatmax did not differ between groups (64.4 ± 14.9 and 61.6 ± 15.4%VO2max). Fatmax or %VO2max that elicited Fatmax was not associated with 10,000 m time. The only variable associated with 10,000-m running per-formance was %VO2max used during the run (p < 0.01). In conclusion, the criteria used for the division of groups according to training status might influence the identification of differences in Fatmax or in the intensity that elicits Fatmax.
... In these studies (Nordby et al., 2006; Stisen et al., 2006), subjects with high and low VO 2 max values were compared, assuming that the higher VO 2 max values represented the more trained subjects. However, even if the VO 2 max is used frequently as a physiological parameter to discriminate the aerobic fitness (Costill et al., 1973; Wyndham et al., 1969), there are some studies that have indicated it may have limited power in predicting the endurance performance (Morgan et al., 1989; Noakes et al., 1990). This limited predictive power could be due to a complex interplay between other physiological factors beyond the VO 2 max and the endurance performance (Weston et al. 1999). ...
This study aimed to compare maximal fat oxidation rate parameters between moderate- and low-performance runners. Eighteen runners performed an incremental treadmill test to estimate individual maximal fat oxidation rate (Fatmax) based on gases measures and a 10,000-m run on a track. The subjects were then divided into a low and moderate performance group using two different criteria: 10,000-m time and VO2max values. When groups were divided using 10,000-m time, there was no significant difference in Fatmax (0.41 ± 0.16 and 0.27 ± 0.12 g.min(-1), p = 0.07) or in the exercise intensity that elicited Fatmax (59.9 ± 16.5 and 68.7 ± 10.3 % O2max, p = 0.23) between the moderate and low performance groups, respectively (p > 0.05). When groups were divided using VO2max values, Fatmax was significantly lower in the low VO2max group than in the high VO2max group (0. 29 ± 0.10 and 0.47 ± 0.17 g.min(-1), respectively, p < 0.05) but the intensity that elicited Fatmax did not differ between groups (64.4 ± 14.9 and 61.6 ± 15.4 %VO2max). Fatmax or %VO2max that elicited Fatmax was not associated with 10,000 m time. The only variable associated with 10,000-m running performance was %VO2max used during the run (p < 0.01). In conclusion, the criteria used for the division of groups according to training status might influence the identification of differences in Fatmax or in the intensity that elicits Fatmax. Key pointsThe results of the present study suggest that the criteria used to categorize aerobic training status of subjects can influence the magnitude of differences in Fatmax.The Fatmax is similar between groups with similar 10,000-m running performance.The 10,000-m running performance seems to be associated with an increased ability to oxidize carbohydrate.
... La consommation maximale d'oxyg~ne ('¢O2max) a &6 consid~r6e pendant longtemps comme un des meilleurs crit6res de pr6diction de la performance dans les disciplines sportives ~ pr6dominance a6ro- bie (Saltin et Astrand, 1967; Wyndham et al, 1969). Cependant, il a 6t6 montr6 plus r6cemment que la performance a6robie d6pend plus du temps d'endurance que de la valeur absolue de la VO2max (Costill et al, 1971 ; ). ...
The time course of blood lactate and ventilatory gas exchange was studied during an incremental exercise test on cycloergometer in order to determine whether the lactate accumulation threshold (SL2) can be accurately estimated by the use of respiratory indices (SV2) in young athletes. Twelve trained subjects, ranging in age from 18 to 22 years participated in this study. The initial power setting was 30 W for 3 min with successive increases of 30 W every min except at the end of the test where the increase was reduced. Ventilatory flow (VE), oxygen uptake (VO2), carbon dioxyde flow (VCO2), ventilaroty equivalents of O2 and of CO2 were determined during the last 30 s of every min. Venous blood samples were drawn at the end of each stage of effort and analyzed enzymatically for lactate concentration. SL2 and SV2 were determined visually by two investigators on graphics according to a double-blind procedure. SL2 was defined as a starting point of accelerated lactate accumulation. SV2 was identified by the increase in VE and ventilatory equivalent for O2 uptake accompanied by a concomitant increase in ventilatory equivalent for CO2 output. The results indicate no significant difference between SL2 and SV2 expressed as VO2 (43.98 ± 1.70 versus 44.93 ± 2.39 ml/kg·min−1), lactatemia (4.01 ± 0.28 versus 4.44 ± 0.37 mM·l−1), or heart rate (171 ± 3.36 versus 173 ± 3,11 beat·min−1). In addition, high correlations were noted between the two methods for VO2 (r = 0.90, P < 0.001), lactatemia (r = 0.75, P < 0.01) and heart rate (r = 0.96, P < 0.001). It is concluded that SV2 coincides with SL2 determination. The ventilatory gas exchange method can thus satisfactorily evaluate the lactate accumulation threshold in young athletes.
... In these studies (Nordby et al., 2006;Stisen et al., 2006), subjects with high and low VO 2 max values were compared, assuming that the higher VO 2 max values represented the more trained subjects. However, even if the VO 2 max is used frequently as a physiological parameter to discriminate the aerobic fitness (Costill et al., 1973;Wyndham et al., 1969), there are some studies that have indicated it may have limited power in predicting the endurance performance (Morgan et al., 1989;Noakes et al., 1990). This limited predictive power could be due to a complex interplay between other physiological factors beyond the VO 2 max and the endurance performance (Weston et al. 1999). ...
http://dx.doi.org/10.5007/1980-0037.2008v10n3p308
The goal of this study was to present a new perspective on the relationship between lipid metabolism and the intensity/duration of exercise and energy expenditure. The idea was to use the second lactate threshold as a marker of the best ratio between energy expenditure and duration of exercise. From the literature review and analyses of experimental data, it was demonstrated that the second lactate threshold mark is the point at which the best ratio occurs between substrate oxidation rate and duration of effort. This means that any low intensity exercise performed below the second lactate threshold will require more time to achieve the same energy expenditure as exercise performed at the second lactate threshold. On the other hand, exercise performed above the second lactate threshold has a higher substrate oxidation rate, but, due to the shorter time for which the effort can be sustained, the total energy expenditure is less. These considerations have important practical applications in training schedules for reducing body fat.
... Although there have been many investigations of the marathon event (Costill and Fox 1969, Costill et al 1971, Maron et al 1976, Wyndham et al 1969), there is little published data concerning the performance of runners over longer distances, (O'Hara et al 1977). This paper presents a study of two runners who attempted the 80 km distance and compares their energy expenditures with values reported for the marathon (Costill and Fox 1969, Costill et al 1971, Maron et al 1976) and for the 160 km distance (O'Hara et al 1977) (V02 max) was measured on each subject using a treadmill , the Beckman Metabolic Measurement Cart (Wilmore et al 1976) and a Cambridge ECG. ...
Data was collected from two men who attempted an 80 km run. Measurements of aerobic power (VO2 max) and determinations of heart rate (HR) and submaximal oxygen consumption (VO2) during treadmill running were carried out one week before the run. Throughout the 80 km run, HR was recorded by telemetry and used together with the laboratory data to estimate VO2 as a percentage of VO2 max. One subject completed the 80 km distance at 58% of VO2 max, the other subject, operating at 74% of VO2 max, was obliged to retired after 55 km. The data in this and other studies indicate that the high energy costs reported for the marathon (70-85% of VO2 max) cannot be sustained over the 80 km distance but that about 60% of VO2 max can be continued for seven hours and longer.
... Physical and physiological characteristics of distance runners have received considerable attention in recent literature. Variables which have been associated with performance in distance running competition include maximal aerobic power (Costill, 1967;Davies and Thompson, 1979;Wyndham et al, 1969;Saltin and Astrand, 1967), body composition (Costill et al, 1970;Novak et al, 1977;Sprynarova and Parizkova, 1971), various training indices (Hagan et al, 1981;Murray et al, 1980;Slovic, 1977), and running economy (Conley and Krahenbuhl, 1981). However prediction of performance times based on these and other parameters is often nebulous. ...
The purpose of this study was to investigate possible factors which may account for differences in performance times within a closely-matched group (in terms of performance) of elite distance runners. The runners were training for competition in the 1984 Olympic Games in either the 5000 m or the 3000 m steeplechase events. Each runner's best performance time (BPT) was obtained and a stepwise regression analysis was performed with the following independent variables: age, weight, % body fat, VO2 max, aerobic threshold (AerT), and anaerobic threshold (AnT). For the 5000 m-runners, a multiple correlation of age and AnT accounted for 77% of the variance (p less than 0.02); for the 3000 m steeplechase runners, body weight alone and body weight and AnT accounted for 94% (p less than .01) and 98% (p less than .05) of the variance, respectively. The results suggest that, among elite middle-distance runners, these parameters deserve attention as potential predictors of performance.
South Africa was founded as a nation in 1910; its research history has been short and distorted politically. The highlights of South African research in thermal physiology of the twentieth century have included contributions to the thermal physiology of livestock, to human thermal physiology, to peripartum thermoregulation and to comparative thermal physiology. The livestock research produced the first assessment of the effects of solar radiation and delivered a new breed of cattle. The human research included the most-comprehensive investigations ever conducted into the thermal physiology of deep-level mining and provided new insights into heat illness. Highlights of the research on peripartum thermal physiology were the first, and still the only, measurements of the temperature of mother and progeny through parturition, and discovery of the phenomenon of foetal thermal protection. The research on comparative thermal physiology discovered African poikilothermic endotherms, explored the thermal physiology of the world’s strangest and the world’s largest birds, and, through biologging of body temperature and activity of free-living animals, revealed that the thermoregulatory mechanisms employed by large mammals in their natural habitats could not be predicted from studies on those same mammals in captivity. A characteristic of South African research as it progresses into the twenty-first century will be continuation of the pioneering spirit of its researchers, and employment of the new technologies that are likely to change the face of thermal physiology: biologgers, radiotelemeters, transponders and thermographic cameras. Of necessity, the thermal physiology of climate change will be an important twenty-first century theme.
(1) The purpose of the present study was to investigate the significance of anaero-bic energy release in two groups of distance runners whose maximal aerobic power was known to be comparable (Vo2max averaged 71.1±1.22 ml/kg· min) but differed each other significantly in their performance of 5, 000m run (group A ; n=6, timed in average 14'50″1±11″0 ; and group B ; n=6, timed in average 15'52″5±14″1) .(2) Twelve runners were subjected to 3 experimental series of treadmill running 1, exhaustive running, 2, two to four trials' of submaximal runnings for 15 min, and 3. running at the intensity corresponding to 90% of maximal oxygen uptake for 14 min, then the“last spurt”for 1 min at 120% of maximal oxygen uptake. In addition, they were asked to sprint up a staircase with their top speed.(3) Exhaustive running time on the treadmill and maximal oxygen debt in group A were 8'56″2±40″8 and 8454±923.7 ml, respectively. Both were significantly larger than 8'02″8±31″0 and 6787±1301.7 ml registered by group B (p<0.05) .(4) Differences between A and B groups in their cardio-respiratory responses during maximal treadmill running, threshold of anaerobic metabolism, anaerobic power, alactic and lactic oxygen debt, maximal lactate concentration, etc. were found to be not significant.(5) These results indicate that the variance in maximal oxygen debt may exert a modifying influence in either positive or negative directions which could be the reason why the same level of aerobic power does not guarantee a comparable performance level in actual running event.
In brief: The author reviews the key research on the physiological determinants of distance running performance and presents a simple model that he thinks should serve as a basis for hypothesis testing in the future. The model has three primary determinants: aerobic capacity relative to body weight, running economy, and the percentage of aerobic capacity used during a race. The author says that the model applies equally to elite runners and recreational joggers and suggests that systematic efforts are needed to translate research findings to a form that is meaningful to clinicians, coaches, and athletes.
In a main axis factor analysis for anthropometric body measurements of 18 female and 92 male long distance runners the following growth factors could be derived: a fat factor - a thoracic and abdominal body mass factor - a length factor and a muscle-bone-factor expressing mesomorphy. There were negative correlationships between the fat factor and cardiopulmonary performance parameters and positive relations between the muscle-bone-factor and cardiopulmonary performance.
Sir Adolphe Abrahams stellt in seinem Artikel über „Athletics“ in der 1950 erschienenen Ausgabe der Britischen Enzyklopädie über praktische Medizin fest, „ich bin der Meinung, daß bei gesunden Personen die einzige ernsthafte potentielle Gefahr für das Leben bei einer intensiven körperlichen Beanspruchung der Hitzschlag ist — eine Gefahr, die deutlich demonstriert wurde von den Beispielen, die ich gesehen habe: alarmierende Kollapse und, bei einer Gelegenheit, ein Todesfall. Eine korrekte Vorsichtsmaßnahme würde das Verbot sein, Rennen unter Umständen zu bestreiten, unter welchen ein derartiger Vorfall erwartet werden könnte — eine feuchtigkeitsbeladene Atmosphäre, ein ebensolcher Wind am frühen Nachmittag oder ein Tag mit einer Temperatur von 85° F (29,5° C) im Schatten oder höher“.
High performance sports medicine involves the medical care of athletes, who are extraordinary individuals and who are exposed to intensive physical and psychological stresses during training and competition. The physician has a broad remit and acts as a 'medical guardian' to optimise health while minimising risks. This review describes this interesting field of medicine, its unique challenges and priorities for the physician in delivering best healthcare.
The purpose of this study was to assess the relationships among ventilatory threshold T(vent), running economy and distance running performance in a group (N=9) of trained experienced male runners with comparable maximum oxygen uptake ([Vdot]O2max). Maximal oxygen uptake and submaximal steady state oxygen uptake were measured using open circuit spirometry during treadmill exercise. Ventilatory threshold was determined during graded treadmill exercise using non-invasive techniques, while distance running performance was assessed by the best finish time in two 10-kilometer (km) road races. The subjects averaged 33.8 minutes on the 10km runs, 68.6 ml · kg -1 · min -1for [Vdot]O2max, and 48.1 ml · kg -1 · min -1for steady state [Vdot]O2running at 243 meters · min -1. The T(vent) (first deviation from linearity of [Vdot]E, [Vdot]CO 2) occurred at an oxygen consumption of 41.9 ml · kg -1 · min -1. The relationship between running economy and performance was r = .51 (p>0.15) and the relationship between T(vent) and performance was r = .94 (p < 0.001). Applying stepwise multiple linear regression, the multiple R did not increase significantly with the addition of variables to the T(vent); however, the combination of [Vdot]O2max, running economy and T(vent) was determined to account for the greatest amount of total variance (89%). These data suggest that among trained and experienced runners with similar [Vdot]O2max, T(vent) can account for a large portion of the variance in performance during a 10km race.
A review of the physiological factors of performance in the 400. The author does an excellent job of relating the physiological factors to the all-important aspect of race distribution. Black was affi liated with Performance Fitness of Cincinnati, Ohio. REPRINTED FROM TRACK COACH #102 (Winter, 1988) Perhaps no other event is as perplexing to track coaches as the 400-meter dash. In contrast to a wealth of information about middle and long distance running and runners (Carter, et al. Bale, Bradbury, and Colley, 1986), there is a lack of scientifi c information about: the immediate and long-term effects of competition and training and the characteristics of outstanding 400-meter performers. This makes it diffi cult to make a rational decision about the best methods for training for this event. In order to answer the question of what is the best method for training 400-meter runners, it is necessary to analyze the nature and demands of the race by de-termining: 1. the responses to competition; and, 2. the characteristics of 400-meter competitors of varying levels of ability. The following information, derived from avail-able literature, can be used as the basis for the rational planning of more effective training programs for the purpose of improving 400-meter racing performance. During 400-meter racing, energy is derived from: 1. the breakdown of high-energy phosphate compounds (20.25%); and 2. the anaerobic productions of ATP by glycolysis (55-60%), and 3. aerobic production of ATP (15-25%). (GIadrow, 1983; Daley, 1978). Of the standard running events, the 400 probably requires the greatest energy production via anaerobic glycolysis, as evidenced by the observation that the most pronounced cases of lactate acidosis in athletic competition occurred after 400 and 800-meter racing. Following a 400-meter dash of 45.5 seconds, an international-caliber runner had a lactate concentration of 24.97 mmol/liter with a pH of 6.923 and a base excess of 30.0 mval/liter. (Kindermann and Keul, 1977). Similar lactate concentration and pH values were reported fol-lowing a run of 47.8 seconds (Osnes and Hermansen, 1972). Research (Schnabel and Kindermann, 1983) indicates that the anaerobic capacity of runners is infl uenced by: 1. the energy derived from the lactacid anaerobic system; 2. energy derived from the alactate anaerobic system; and, 3. energy derived from aerobic metabolism. Those three factors were found to account for 57, 31, and 5% of the variability between groups of 400-meter, middle distance, long distance, and marathon runners in a short-duration run to exhaustion. The most pronounced difference between 400-me-ter runners with a mean best time of 45.6 seconds, and those with a mean best of 48.0 seconds was that the better 400 runners apparently produced more energy via the alactate anaerobic energy system. Although the apparent difference did not reach statistical signifi cance, this fi nding led the researchers to hypothesize that the superior 400-meter runners may be characterized by "an extraordinarily high capacity to increase their alactacid anaerobic capacity." Lending support to this observation is the fi nding of Jolly and Crowder (1985) that trained sprinters were able to both accelerate and maintain maximum velocity for a greater distance than untrained sprinters with similar maximum velocity capabilities, leading to the hypothesis that the trained sprinters may have increased levels of PC in the working muscles which extends the time before energy is supplied by anaerobic glycolysis. The research of VanCoppenolle (1980) found that: 1. 400-meter dashes run in 43.8-44.9 seconds were accomplished by running the fi rst and second 200 meters in a mean time of 21.5 (20.7-22.4) and 23.0 (22.1-23.5) seconds, respectively. 400-meters run in 45.0-45.9 sec-onds were run with the fi rst and second 200s covered in mean times of 21.7 (20.8-22.7) and 23.8 (22.5-25.0).
Maximal oxygen uptake (V̇O2 max) has been described as an important characteristic of endurance athletes. Early investigations by Robinson, Edwards, and Dill, and Saltin and Astrand reported V̇O2 max values above 80 ml/kg.min for distance runners and cross-country skiers. Saltin and Astrand further documented a differentiation in V̇O2 max in a variety of athletic types. A more recent study showed that although V̇O2 max differentiated well in endurance athletes of diverse abilities, there was a limitation of using V̇O2 max to predict distance running performance of good runners. Costill et al. and Costill, Thomason, and Roberts found that the fractional utilization of VO2 at a standard running speed to be an important measure in predicting V̇O2 capacity in good distance runners. Running efficiency from the standpoint of energy expenditure may also be an important factor in differentiating distance runners. It has been suggested that differences may exist in some metabolic variables between elite marathon runners (26.2 miles or 42 km) and other elite types of middle-long distance runners (1-6 miles or 1,500-10,000 m). As metabolic and efficiency differences may prove more predictive in differentiating among elite runners, it was the purpose of this investigation to study the submaximal and maximal metabolic characteristics of a large sample of elite runners to observe if specific differentiation into the types of runner could be made.
Five trained males aged 20–23 years undertook successive phases (2–5 weeks duration) of daily training in normoxia or hypoxia. Weekly exhaustive tests alternately in normoxia or hypoxia, throughout, assessed the comparative efficacy of the training. The relative contribution to endurance, aerobic (peak VO2) and anaerobic (δLa) power made by exercise or hypoxia separately was studied.
In a stepwise increasing work test to exhaustion relative bradycardia developed during the first minute of exhaustive work at 1800 kgm/min in all subjects and aerobic power increased both in normoxia and hypoxia significantly by the end of the first phase hypoxic training. Endurance for exhaustive work increased in both environments as did aerobic and anaerobic power.
The purpose of this study was to compare the oxygen cost of running as it relates to speed of running among the following four groups: trained male distance runners, trained female distance runners, untrained but active men and women. Each subject was given a series of treadmill tests during which Vo2 was measured at submaximal work loads. The linear regression equation was utilized to compute the relationship between Vo2 and running speed for each groups. The results indicated that the rate of increase in Vo2 for a given increase in running speed could be represented as a straight line and was the same for all groups (P greater than .05). The trained male runners had a significantly lower Vo2 (P less than .05) than those of the other three groups at any measured speed. The trained females and untrained males had significantly lower Vo2s than the untrained females (P less than .05) at any of the given range of speeds. No significant differences were observed between the untrained mean and trained women (P greater than .05). It was concluded that there were differences in the oxygen cost of running not only between the trained and untrained groups but also between males and females.
The current investigation was designed to determine which factor or what combination of factors would best account for distance running performance in middle-aged and elderly runners (mean age 57.5 years SD +/- 9.7) with heterogeneous training habits. Among 35 independent variables which were arbitrarily selected as possible prerequisites in the distance running performance of these runners, oxygen uptake (VO2) at lactate threshold (LT) (r = 0.781-0.889), maximal oxygen uptake (VO2 max) (r = 0.751 approximately 0.886), and chronological age (r = -0.736-(-)0.886) were found to be the 3 predictor variables showing the highest correlations with the mean running velocity at 5 km (V5km), 10 km (V10km), and marathon (VM). When all independent variables were used in a multiple regression analysis, any 3 or 4 variables selected from among VO2 at LT, chronological age, systolic blood pressure (SBP), atherogenic index (AI), and Katsura index (KI) were found to give the best explanation of V5km, V10km, or VM in a combined linear model. Linear multiple regression equations constructed for predicting the running performances were: V5km = 0.046X1-0.026X2-0.0056X3+5.17, V10km = 0.028X1-0.028X2-0.190X4-1.34X5+6.45, and VM = -0.0400X2-0.324X4-1.16X5+7.36, where X1 = VO2 at LT (ml.min-1.kg-1), X2 = chronological age, X3 = SBP, X4 = AI, and X5 = KI.(ABSTRACT TRUNCATED AT 250 WORDS)
Twenty specialist marathon runners and 23 specialist ultra-marathon runners underwent maximal exercise testing to determine the relative value of maximum oxygen consumption (VO2max), peak treadmill running velocity, running velocity at the lactate turnpoint, VO2 at 16 km h-1, % VO2max at 16 km h-1, and running time in other races, for predicting performance in races of 10-90 km. Race time at 10 or 21.1 km was the best predictor of performance at 42.2 km in specialist marathon runners and at 42.2 and 90 km in specialist ultra-marathon runners (r = 0.91-0.97). Peak treadmill running velocity was the best laboratory-measured predictor of performance (r = -0.88(-)-0.94) at all distances in ultra-marathon specialists and at all distances except 42.2 km in marathon specialists. Other predictive variables were running velocity at the lactate turnpoint (r = -0.80(-)-0.92); % VO2max at 16 km h-1 (r = 0.76-0.90) and VO2max (r = 0.55(-)-0.86). Peak blood lactate concentrations (r = 0.68-0.71) and VO2 at 16 km h-1 (r = 0.10-0.61) were less good predictors. These data indicate: (i) that in groups of trained long distance runners, the physiological factors that determine success in races of 10-90 km are the same; thus there may not be variables that predict success uniquely in either 10 km, marathon or ultra-marathon runners, and (ii) that peak treadmill running velocity is at least as good a predictor of running performance as is the lactate turnpoint. Factors that determine the peak treadmill running velocity are not known but are not likely to be related to maximum rates of muscle oxygen utilization.
One of the most fundamental beliefs in exercise physiology is that performance during maximum exercise of short duration is limited by the inability of the heart and lungs to provide oxygen at a rate sufficiently fast to fuel energy production by the active muscle mass. This belief originates from work undertaken in the 1920's by Hill and Lupton. A result is that most, if not all, of the studies explaining the effects of exercise training or detraining or other interventions on human physiology explain these changes in terms either of central adaptations increasing oxygen delivery to muscle or of peripheral adaptations that modify the rates of oxygen or fuel utilization by the active muscles. Yet a critical review of Hill and Lupton's results shows that they inferred but certainly did not prove that oxygen limitation develops during maximal exercise. Furthermore, more modern studies suggest that, if such an oxygen limitation does indeed occur during maximal exercise, it develops in about 50% of test subjects. Thus, an alternative mechanism may need to be evoked to explain exhaustion during maximal exercise in a rather large group of subjects. This review proposes that the factors limiting maximal exercise performance might be better explained in terms of a failure of muscle contractility ("muscle power"), which may be independent of tissue oxygen deficiency. The implications for exercise testing and the prediction of athletic performance are discussed.
Recent reports have suggested that running economy (RE) defined as oxygen consumption at standardized treadmill speeds may be an important determinant for successful distance running performance. The purpose of this study was to examine the additional role, if any, played by anaerobic factors in distance running performance. Highly trained male cross-country runners (N = 12) were administered a battery of standardized aerobic and anaerobic laboratory evaluations. Maximal oxygen uptake (VO2max) and RE (ml X kg-1) were measured using open circuit spirometry during treadmill exercise. RE was measured at 241 and 295 m X min-1, and ventilatory threshold (Tvent) was determined and verified using a number of non-invasive ventilatory measures (VE, VE/VO2, VE/VCO2, VCO2, FECO2). Anaerobic measures included the Margaria power test and the Monod critical power test to determine anaerobic work capacity (AWC). The data were subjected to a SAS-STEPWISE analysis which combines stepwise addition and backward elimination and were used to predict performance time in a 8.05-km (5-mile) cross-country race in which all the runners participated. The subjects averaged 26.21 min for the 8.05 km run, with 72.1 ml X kg-1 X min-1 for the VO2max with a Tvent at 60.4 ml X kg-1 X min-1 (84% VO2max). AWC (Monod) was 17400 Joules with a range of 8,000-28,400 Joules. The STEPWISE procedure reveals that AWC contributes significantly (P less than 0.003) to a 3 variable model predicting race performance (R2 = 0.76, P less than 0.01). AWC accounts for 58% of total shared variance with VO2max and an indirect measure of Tvent accounting for the remaining 17%.(ABSTRACT TRUNCATED AT 250 WORDS)
Field and laboratory studies were made on 16 trained distance runners to determine the relationship between selected metabolic measurements and distance running performance. Measurements were made for oxygen consumption, heart rate, and blood lactate accumulation during submaximal and maximal treadmill running. Several days after the laboratory test all of the runners competed in a 10-mile road race. The correlation between max[latin capital V with dot above]o2 (ml/kg x min) and performance in the 10-mile race (min) was -0.91 At a selected speed (268 m/min) the % max[latin capital V with dot above]o2 and % max HR were found to be highly related to distance running performance (r = -0.94 and 0.98, respectively). At all running speeds above 70% max[latin capital V with dot above]o2 the faster runners were found to accumulate less blood lactate than the slower runners at similar speeds and relative percentages of their aerobic capacities. The findings suggest that successful distance running is dependent on the economical utilization of a highly developed aerobic capacity and the ability to employ a large fraction of that capacity with minimal accumulation of lactic acid. (C)1973The American College of Sports Medicine
Summary Metabolic responses during submaximal and maximal treadmill running were measured for a world champion marathon runner. Oxygen consumption, heart rates and lactic acid were recorded during a series of 8 submaximal and 2 maximal trials. One 30 min run was performed at a pace which equaled the runner's best world performance (328 m/min). His maximal oxygen consumption (max
$$\dot V_{\operatorname{o} _2 } $$
) was 5.091/min (69.7 ml/kg-min) with a maximal heart rate of 188 beats/min. During the 30 min run he utilized 86% of his aerobic capacity with a heart rate of 167 beats/min. When compared with other marathon runners this subject demonstrated little superiority with respect to either aerobic capacity or the energy requirements at various running speeds. The findings of this research suggest that marathon running success is dependent upon running economy and the ability to utilize a large fraction of a well developed aerobic capacity.
The extent to which differences between men and women in cardiorespiratory capacity (VO2max in ml X min-1 X kg FFW-1), percent fat, and running economy (VO2 in ml X min-1 X kg BW-1 at 188 m X min-1) account for the sex difference in 12-min run performance was investigated in 34 male and 34 female recreational runners, 19-35 yr of age. Men differed significantly (P less than 0.05) from women in VO2max (68.6 vs 65.1 ml X min-1 X kg FFW-1), percent fat, (10.8 vs 19.8%), and 12-min run performance (3294 vs 2747 m), but not in running economy (39.0 vs 39.1 ml X min-1 X kg BW-1). Simple and multiple regression and correlation analyses indicated that relations of the biological variables to 12-min run performance were similar within groups of men and women. Multiple regression analysis revealed that percent fat, VO2max (ml X min-1 X kg FFW-1), and running economy accounted for 74, 20, and 2% of the average sex difference in 12-min run performance, respectively. It was concluded that for men and women similarly trained, the average sex difference in 12-min run performance is primarily due to differences in percent fat and cardiorespiratory capacity. If the observed differences between men and women on these variables are truly a function of sex, results of this study provide a biological basis for different distance running performance expectations for men and women.
The maximal ability to deliver oxygen to the tissues of the body establishes the upper limit of endurance performance; however, the ability of the skeletal muscles to utilize a high oxygen load for a sustained period of time is also of great importance. The fatigue that limits endurance is due to a local limitation of oxygen or substrate, which leads to excessive anaerobic metabolism or decreased energy production. The peripheral adaptation from specific and intense training may further improve endurance performance.
The relationship between running speed (RS) and heart rate (HR) was determined in 210 runners. On a 400-m track the athletes ran continuously from an initial velocity of 12-14 km/h to submaximal velocities varying according to the athlete's capability. The HRs were determined through ECG. In all athletes examined, a deflection from the expected linearity of the RS-HR relationship was observed at submaximal RS. The test-retest correlation for the velocities at which this deflection from linearity occurred (Vd) determined in 26 athletes was 0.99. The velocity at the anaerobic threshold (AT), established by means of blood lactate measurements, and Vd were coincident in 10 runners. The correlation between Vd and average running speed (mean RS) in competition was 0.93 in the 5,000 m (mean Vd = 19.13 +/- 1.08 km/h; mean RS = 20.25 +/- 1.15 km/h), 0.95 in the marathon (mean Vd = 18.85 +/- 1.15 km/h; mean RS = 17.40 +/- 1.14 km/h), and 0.99 in the 1-h race (mean Vd = 18.70 +/- 0.98 km/h; mean RS = 18.65 +/- 0.92 km/h), thus showing that AT is critical in determining the running pace in aerobic competitive events.
The purpose of this study was to examine the relationship of marathon performance time (MPT) with maximal aerobic power (VO2max), body composition, and training factors recorded for 9 wk prior to a race. Fifty males, 21 to 61 years of age (mean = 36 yr) with a mean weight of 69.6 kg, kept daily exercise records which included the distance and time run for each workout. VO2max ranged from 52.7 to 88.6 ml x kg-1 x min-1; total km for the 9 wk period ranged from 372 to 1260; km per workout ranged from 6.1 to 20.6; total workout days ranged from 28 to 61; and MPT ranged from 139 to 298 min. MPT was inversely related to VO2max (r = -0.63), total km (r = -0.67), average km per workout (r = -0.64), and total workout days (r = -0.62). MPT was slightly correlated with body weight (r = 0.41) and the sigma 7 skinfolds (r = 0.41). For a group of runners which includes both novice and experienced marathoners, MPT may be predicted (R2 = 0.71) by the following equation: MPT (min) = 525.9 + 7.09 (km x workout-1) -0.45 workout speed, m x min-1) -0.17 (total km for 9 wk) -2.01 (VO2max, ml x kg-1 x min-1) -1.24 (age, yr). These findings suggest that a high maximal aerobic power, low body mass, daily workouts, and training runs of long duration and distance contribute to better performance times in the marathon.
Anaerobic threshold (AT) and maximum oxygen uptake (max VO2) were determined in 15 young female cross-country skiers, aged 15--20 years, during incremental bycycle ergometer exercise. Succinate dehydrogenase (SDH), malate dehydrogenase (MDH), citrate synthase (CS) and lactate dehydrogenase (LDH) were analyzed biochemically and percentage of slow twitch fibres (%ST fibres, myosin adenosine triphosphatase staining) histochemically in muscle samples obtained from m. vastus lateralis. Max VO2 correlated significantly with anaerobic threshold in ml x kg-1 x min-1 (mlAT) but when AT was expressed in percent of max VO2 (%AT) the correlation was insignificant. Significant correlations were found between %AT and SDH (r = 0.63) and between mlAT and CS (r = 0.58). Max VO2 showed no significant correlations with the enzymes studied or %ST fibres. The results of the study seem to support the hypothesis that anaerobic threshold is related to oxidative capacity of muscle.
The purpose of this investigation was to evaluate and quantify physiological differences among groups of distance runners. The subjects included 20 elite distance runners (8 marathon, 12 middle-long distance) and 8 good runners. Working capacity and cardiorespiratory function were determined by submaximal and maximal treadmill tests, and body composition by hydrostatic weighing. The variables studied were maximum oxygen uptake ([Vdot]O2 max), [Vdot]O2 submax, lactic acid submax, lean body weight, and fat weight. MANOVA showed that the good runners differed from the elite runners (p < 0.01) and the elite marathon runners differed from the elite middle-long distance runners (p < 0.05). Discriminant analysis showed that both functions were significant. The first was a general physiological efficiency factor that separated the good and elite runners. The second separated the elite marathon and middle-long distance groups. The second function showed that the marathon runners had lower lactic acid submax values. The middle-long distance runners had higher [Vdot]O2 max values. Classification analysis was used to evaluate the accuracy of the discriminant analysis; 80% of the elite runners were correctly classified as marathon or middle-long distance runners. The discriminant functions were used to develop a multivariate scaling model for evaluating distance runners. Two premier runners, one marathoner (F. Shorter) and one middle-long distance runner (S. Prefontaine), were found to be at the extremes of the scale. The data showed that the discriminant functions provided a valid model for evaluating differences among elite distance runners.
The purpose of the study was to determine the relationship between running economy and distance running performance in highly trained and experienced distance runners of comparable ability. Oxygen uptake (Vo2) during steady-state and maximal aerobic power (Vo2max) were measured during treadmill running using the open-circuit method. Distance running performance was determined in a nationally prominent 10 km race; all subjects (12 males) placed among the top 19 finishers. The subjects averaged 32.1 min on the 10 km run, 71.7 ml.kg-1.min-1 for Vo2max, and 44.7, 50.3, and 55.9 ml.kg-1.min-1 for steady-state Vo2 at three running paces (241, 268, and 295 m.min-1). The relationship between Vo2max and distance running performance was r = -0.12 (p = 0.35). The relationship between steady-state Vo2 at 241, 268 and 295 m.min-1 and 10 km time were r = 0.83, 0.82, and 0.79 (p < 0.01), respectively. Within this elite cluster of finishers, 65.4% of the variation observed in race performance time on the 10 km run could be explained by variation in running economy. It was concluded that among highly trained and experienced runners of comparable ability and similar Vo2max, running economy accounts for a large and significant amount of the variation observed in performance on a 10 km race.
Laboratory and field assessments were made on eighteen male distance runners. Performance data were obtained for distances of 3.2, 9.7, 15, 19.3 km (n = 18) and the marathon (n = 13). Muscle fiber composition expressed as percent of slow twitch fibers (%ST), maximal oxygen consumption (VO2max), running economy (VO2 for a treadmill velocity of 268 m/min), and the VO2 and treadmill velocity corresponding to the onset of plasma lactate accumulation (OPLA) were determined for each subject. %ST (R > or equal to .47), VO2max (r > or equal to .83), running economy (r > or equal to .49), VO2 in ml/kg min corresponding to the OPLA (r > or equal to .91) and the treadmill velocity corresponding to OPLA (r > or equal to .91) were significantly (p < .05) related to performance at all distances. Multiple regression analysis showed that the treadmill velocity corresponding to the OPLA was most closely related to performance and the addition of other factors did not significantly raise the multiple R values suggesting that these other variables may interact with the purpose of keeping plasma lactates low during distance races. The slowest and fastest marathoners ran their marathons 7 and 3 m/min faster than their treadmill velocities corresponding to their OPLA which indicates that this relationship is independent of the competitive level of the runner. Runners appear to set a race pace which allows the utilization of the largest possible VO2 which just avoids the exponential rise in plasma lactate.
:The purpose of this study was to provide a predictive peak oxygen uptake ([V]O(2) peak) equation in wheelchair-dependent athletes using the Adapted Léger and Boucher test. SUBJECTS AND PROTOCOL: :Fifty-six wheelchair-dependent athletes, 47 males and nine females (30.3+/-4 years), underwent a clinical examination to assess their anthropometric characteristics: height, mass, body mass index (BMI), lean body mass, arm length, and muscular arm volume. They performed a deceleration field test to assess the subject-wheelchair resistance defined as a mechanical variable, and they then performed the Adapted Léger and Boucher test to assess physiological data at maximal exercise ([V]O(2) peak, heart rate max) concomitantly with biomechanical (number of pushes) and performance variables (maximal aerobic velocity Va(max) and maximal distance). The [V]O(2) peak was measured directly using a portable telemetric oxygen analyzer. Subjects were then randomly assigned to an experimental group (n=49) to determine the predictive equation, and a validation group (n=7) to check the external validity of the equation.
A stepwise multiple regression with [V]O(2) peak (l min(-1)) as the dependent variable led to the following equation: [V]O(2) peak=0.22 Va(max) - 0.63 log(age)+0.05 BMI 0.25 level+0.52, with r(2)=0.81 and SEE=0.01. Paraplegic subjects with high and low lesion level spinal injuries were attributed the coefficient of 1 and 0, respectively. The external validity of the equation was positive since the predicted [V]O(2) peak values did not significantly differ from directly measured [V]O(2) peak (P>0.05).
We concluded that [V]O(2) peak in wheelchair-dependent athletes was predictable using the equation of the present study and the described incremental test.
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