Content uploaded by Carl Foster
Author content
All content in this area was uploaded by Carl Foster on Mar 29, 2016
Content may be subject to copyright.
Abstract
The importance of the maximal oxygen uptake (VO2 max) for competitive running performance is established. Although of clear importance, the quantitative association between the volume and intensity of training, and running performance has not been established. The purpose of this investigation was to quantify the relative importance of VO2 max, training volume (miles/week) and intensity for running performance at distances ranging from 1.0 to 26.2 miles. Seventy‐eight well‐trained runners of widely varying ability were studied during uphill treadmill running to determine VO2 max. They provided training records to determine training volume and intensity, and participated in races of 1.0 (n = 31), 2.0 (n = 55), 3.0 (n = 28), 6.0 (n= 17), 10.0 (n = 20) and 26.2 (n = 25) miles. The relationship of VO2 max and training volume and intensity to performance was determined using multiple regression. Performance (running time) was highly correlated with VO2 max (r= ‐0.91, ‐0.92, ‐0.94, ‐0.96, ‐0.95 and ‐0.96 for 1.0, 2.0, 3.0, 6.0, 10.0 and 26.2 miles, respectively). The addition of training measures improved the multiple correlations in some (1.0, 2.0, 3.0 and 6.0 miles) but not all (10.0 and 26.2 miles) events. However, even when addition of one or both training indices improved the multiple correlation, the net reduction in the standard error of estimate was small. The results imply that the volume and intensity of training, per se, are relatively minor determinants of cross‐sectional differences in competitive running performance.
... 36 This seems to be a significant factor in the differences in race times outlined above, particularly for middle and longdistance events. 37 In terms of strength, it is well known that males have a greater capacity for maximal strength tasks such as weightlifting. 38 One study performed two correlational observations, during which they found that in the first observation of national-level USA weightlifters, males (n = 39) displayed greater strength relative to bodyweight in the squat (22%), snatch (27%) and clean (28%) movements compared to females (n = 26). ...
... It is unclear whether changes in haemoglobin reflect changes in endurance performance, with a clear lack of studies exploring this area. A focus of further research should be on evaluating potential changes in VO 2 max in trans individuals using GAHT, given that VO 2 max is a major predictor of performance in sports such as distance cycling and distance running, 37,86,87 with clear sex differences in this measure reported. 36 There is a clear lack of control for confounders in this area, with factors such as body size, muscle mass and fat mass not considered during analysis in previous studies. ...
Many transgender (trans) individuals utilize gender-affirming hormone therapy (GAHT) to promote changes in secondary sex characteristics to affirm their gender. Participation rates of trans people in sport are exceedingly low, yet given high rates of depression and increased cardiovascular risk, the potential benefits of sports participation are great. In this review, we provide an overview of the evidence surrounding the effects of GAHT on multiple performance-related phenotypes, as well as current limitations. Whilst data is clear that there are differences between males and females, there is a lack of quality evidence assessing the impact of GAHT on athletic performance. Twelve months of GAHT leads to testosterone concentrations that align with reference ranges of the affirmed gender. Feminizing GAHT in trans women increases fat mass and decreases lean mass, with opposite effects observed in trans men with masculinizing GAHT. In trans men, an increase in muscle strength and athletic performance is observed. In trans women, muscle strength is shown to decrease or not change following 12 months of GAHT. Haemoglobin, a measure of oxygen transport, changes to that of the affirmed gender within 6 months of GAHT, with very limited data to suggest possible reductions in maximal oxygen uptake as a result of feminizing GAHT. Current limitations of this field include a lack of long-term studies, adequate group comparisons and adjustment for confounding factors (e.g. height and lean body mass), and small sample sizes. There also remains limited data on endurance, cardiac or respiratory function, with further longitudinal studies on GAHT needed to address current limitations and provide more robust data to inform inclusive and fair sporting programmes, policies and guidelines.
... In preparing for long distance races, runners are attempting to improve their VO2max through purposeful training, to allow the body to work at higher levels before needing to use the anaerobic system as the energy pathway (18). This means running at faster velocities without expending as much energy (18). ...
... In preparing for long distance races, runners are attempting to improve their VO2max through purposeful training, to allow the body to work at higher levels before needing to use the anaerobic system as the energy pathway (18). This means running at faster velocities without expending as much energy (18). When walking, people are between 15 and 30% of their VO2max, solely using their aerobic process, with the percentage increasing with exertion (14). ...
Introduction
Runners competing in races are looking to optimize their performance. In this paper, a runner's performance in a race, such as a marathon, is formulated as an optimal control problem where the controls are: the nutrition intake throughout the race and the propulsion force of the runner. As nutrition is an integral part of successfully running long distance races, it needs to be included in models of running strategies.
Methods
We formulate a system of ordinary differential equations to represent the velocity, fat energy, glycogen energy, and nutrition for a runner competing in a long-distance race. The energy compartments represent the energy sources available in the runner's body. We allocate the energy source from which the runner draws, based on how fast the runner is moving. The food consumed during the race is a source term for the nutrition differential equation. With our model, we are investigating strategies to manage the nutrition and propulsion force in order to minimize the running time in a fixed distance race. This requires the solution of a nontrivial singular control problem.
Results
As the goal of an optimal control model is to determine the optimal strategy, comparing our results against real data presents a challenge; however, in comparing our results to the world record for the marathon, our results differed by 0.4%, 31 seconds. Per each additional gel consumed, the runner is able to run 0.5 to 0.7 kilometers further in the same amount of time, resulting in a 7.75% increase in taking five 100 calorie gels vs no nutrition.
Discussion
Our results confirm the belief that the most effective way to run a race is to run approximately the same pace the entire race without letting one's energies hit zero, by consuming in-race nutrition. While this model does not take all factors into account, we consider it a building block for future models, considering our novel energy representation, and in-race nutrition.
... There are several physiological factors that are responsible for performance in middle and long distance running: the maximum oxygen uptake (VO 2max ) [1][2][3], the running speed at which VO 2max is reached (vVO 2max ) [2,4], running economy (RE) [5][6][7], a threshold capacity in terms of a lactate (LT) or ventilatory threshold (VT), or the speed at that threshold (vLT), respectively, refs. [8][9][10][11] as well as the utilization of VO 2max at a defined performance level (%VO 2max ) [12,13]. ...
With Norway's successes in middle and long-distance running, lactate-guided threshold training has regained importance in recent years. Therefore, the aim of the present study was to investigate the individual responses on common monitoring parameters based on a lactate-guided conventional training method. In total, 15 trained runners (10 males, 5 females; 18.6 ± 3.3 years; VO2max : 59.3 ± 5.9 mL kg −1 min −1) completed a 40-min continuous running session at a fixed lactate threshold load of 2 mmol L−1. Lactate (La), oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were recorded. The chosen workload led to lactate values of 2.85 ± 0.56 mmol L −1 (range: 1.90-3.80), a percentage of VO 2max utilization (%VO2max) of 79.2 ± 2.5% (range: 74.9-83.8), a percentage of HR max utilization (%HRmax) of 92.2 ± 2.5% (range: 88.1-95.3), and an RPE of 6.1 ± 1.9 (range: 3-10) at the end of the running session. Thereby, the individual responses differed considerably. These results indicate that a conventional continuous training method based on a fixed lactate threshold can lead to different individual responses, potentially resulting in various physiological impacts. Moreover, correlation analyses suggest that athletes with higher lactate threshold performance levels must choose their intensity in continuous training methods more conservatively (lower percentage intensity based on a fixed threshold) to avoid eliciting excessively strong metabolic responses.
... V O2max is the maximal rate that oxygen can be taken up from the air and subsequently be transported to, as well as used by, cells for cellular respiration during physical activity (Hill & Lupton, 1923). It is considered by some to be the single most important determinant of endurance performance (Brandon, 1995;Foster, 1983;Holmberg, 2015). Regarding V O2max, this metric is often used synonymously with an individual's capacity to produce (i.e. ...
Background: Time spent above 90% of maximal oxygen uptake (V̇ O2max) has been shown to
be a valuable indicator of high-intensity interval training (HI[I]T) effectiveness. This study
aimed to investigate whether variations in exercise intensity during an interval could lead to
increased responses of the physiological systems associated with aerobic exercise performance.
We hypothesized that a varied intensity protocol (VAR), vs. a work-matched constant intensity
protocol (CON), would elicit a higher time spent above 90% V̇ O2max and evoke a higher skeletal
muscle fractional O2 utilization/extraction, as measured by the drop in tissue saturation index
(ΔTSI) with the NIRS technology.
Materials & Methods: Nineteen participants (177.2 ± 8.9 cm, 71.7 ± 9.6 kg, 34 ± 12 years,
3687 ± 665 mL.min-1
absolute V̇ O2max, 51.9 ± 6.1 mL.min-1.kg-1
relative V̇ O2max) completed two
HI[I]T protocols of 4 x 5 minutes with 3 minutes rest in between intervals: one constant-power
(CON) and one varying-power (VAR) protocol. The VAR protocol consisted of two surges at
100% of maximum aerobic power (MAP) at the beginning and the middle of the interval,
interspersed with sections at 75% of MAP. The CON protocol was work-matched to the VAR
protocol and ridden at a constant power output. V̇ O2max, MAP and the maximal drop in TSI
(ΔTSImax) were assessed in an incremental exercise test to voluntary exhaustion. Time spent
above 90%V̇ O2max (T>90%V̇ O2max) and 90% ΔTSImax (T>90%ΔTSImax) were the primary
outcomes of interest.
Results: For T>90%V̇ O2max, there was no significant difference between the VAR (437 ± 420
s) and CON (372 ± 375 s) protocols (t(19) = 1.02, p = 0.32). Similarly, there was no significant
difference in T>90%ΔTSImax between the VAR (397 ± 402 s) and CON (394 ± 440 s) protocols
(t(15) = 0.05, p = 0.96).
Conclusions: Our results did not support the hypothesis that a varied intensity protocol (VAR)
would elicit a higher time spent above 90% V̇ O2max or higher skeletal muscle fractional O2
utilization/extraction compared to a work-matched constant intensity protocol (CON). Further
research is needed to explore the potential benefits of varied intensity HI[I]T protocols on
aerobic capacity and other aspects of exercise performance.
... It can effectively simulate the physiological responses of athletes during competition, is often used to evaluate the specific performance of athletes, and is closely related to endurance performance [36,39]. TTE, _ VO2max, and EM are typical indicators that objectively and directly reflect specific exercise and aerobic capabilities [34,37,39,40]. The TTE test requires subjects to perform submaximal exercise intensity to exhaustion until they no longer maintain the required work rate (e.g., speed or power output) [33,37]. ...
Objective:
To assess the responses to taper in endurance athletes using meta-analysis.
Methods:
Systematic searches were conducted in China National Knowledge Infrastructure, PubMed, Web of Science, SPORTDiscus, and EMBASE databases. Standardized mean difference (SMD) and 95% confidence interval (CI) of outcome measures were calculated as effect sizes.
Results:
14 studies were included in this meta-analysis. Significant improvements were found between pre- and post-tapering in time-trial (TT) performance (SMD = -0.45; P < 0.05) and time to exhaustion (TTE) performance (SMD = 1.28; P < 0.05). However, There were no improvements in maximal oxygen consumption ([Formula: see text]) and economy of movement (EM) (P > 0.05) between pre- and post-tapering. Further subgroup analysis showed that tapering combined with pre-taper overload training had a more significant effect on TT performance than conventional tapering (P < 0.05). A tapering strategy that reduced training volume by 41-60%, maintained training intensity and frequency, lasted ≤7 days, 8-14 days, or 15-21 days, used a progressive or step taper could significantly improve TT performance (P < 0.05).
Conclusions:
The tapering applied in conjunction with pre-taper overload training seems to be more conducive to maximize performance gains. Current evidence suggests that a ≤21-day taper, in which training volume is progressively reduced by 41-60% without changing training intensity or frequency, is an effective tapering strategy.
... The main physiological performance determinants which account for success in distance running events are: maximal oxygen uptake (VO 2max ) [4][5][6]; running economy (RE), defined as steady-state VO 2 at a given submaximal speed or as the VO 2 per unit of distance [5,[7][8][9]; the ability to sustain a high percentage of VO 2max during competition (% VO 2max ) [10][11][12]; the lactate threshold (LT), defined either as the velocity at which a non-linear increase in blood lactate occurs, the maximal lactate steady-state (MLSS), or the velocity corresponding to a blood lactate concentration of 4 mmol·L −1 [13]; velocity at LT (vLT)/MLSS [14,15]; and the minimum velocity needed to achieve VO 2max (vVO 2max ) [6,16,17]. To improve distance running performance, the training stimulus must enhance one or more of these factors [18]. ...
The aim of the present study was to describe a novel training model based on lactate-guided threshold interval training (LGTIT) within a high-volume, low-intensity approach, which characterizes the training pattern in some world-class middle- and long-distance runners and to review the potential physiological mechanisms explaining its effectiveness. This training model consists of performing three to four LGTIT sessions and one VO2max intensity session weekly. In addition, low intensity running is performed up to an overall volume of 150–180 km/week. During LGTIT sessions, the training pace is dictated by a blood lactate concentration target (i.e., internal rather than external training load), typically ranging from 2 to 4.5 mmol·L−1, measured every one to three repetitions. That intensity may allow for a more rapid recovery through a lower central and peripheral fatigue between high-intensity sessions compared with that of greater intensities and, therefore, a greater weekly volume of these specific workouts. The interval character of LGTIT allows for the achievement of high absolute training speeds and, thus, maximizing the number of motor units recruited, despite a relatively low metabolic intensity (i.e., threshold zone). This model may increase the mitochondrial proliferation through the optimization of both calcium and adenosine monophosphate activated protein kinase (AMPK) signaling pathways.
... T he measurement of an individual's maximal oxygen uptake (VO 2max ) is a foundational assessment of cardiorespiratory fitness in both athletic and clinical populations (1,2). Typically,VO 2max is determined from an incremental test; however, there is not a consensus within the literature on the methodology (e.g., ramp vs step increments) to properly measureVO 2max in all populations (3). ...
Purpose:
A square-wave verification bout to confirm maximal oxygen uptake (V̇O2max) from a graded exercise test (GXT) has been recommended based on mean responses. This study used the test-retest reliability, mean, and individual differences between the highest V̇O2 from the GXT (V̇O2GXT) and verification bout (V̇O2verification) to examine the efficacy of a verification bout in the determination of O2max in healthy, recreationally trained, well-motivated men.
Methods:
Ten men (24 ± 4 years) completed a GXT on a cycle ergometer followed by a submaximal verification bout to determine V̇O2GXT and V̇O2verification. After completion of the initial GXT, subjects rested for 5 min then performed the verification bout at 90% of the peak power output from the initial GXT. Analyses included a 2-way repeated-measures ANOVA, intra-class correlation coefficients (ICC2,1), standard errors of the measurement (SEM), minimal differences (MD), and coefficients of variation (CoV).
Results:
There was no test (test 1 vs test 2) x method (GXT vs verification) interaction (p = 0.300), and no main effect for test (p = 0.690), but there was a main effect for method (p = 0.003). The V̇O2GXT (46.0 mL⋅kg-1⋅min-1) was significantly greater than V̇O2verification (43.9 mL⋅kg-1⋅min-1), collapsed across test. The V̇O2GXT (ICC = 0.970, SEM = 1.63 mL⋅kg-1⋅min-1, MD = 4.51 mL⋅kg-1⋅min-1, CoV = 3.54%) and V̇O2verification (ICC = 0.953, SEM = 1.87 mL⋅kg-1⋅min-1, MD =5.17 mL⋅kg-1⋅min-1, CoV =4.25%) demonstrated "excellent" reliability. No subject exceeded the MD test-retest for V̇O2GXT or V̇O2verification. No subject had a V̇O2verification that exceeded V̇O2GXT by more than the MD, but 2 subjects had a V̇O2GXT which exceeded V̇O2verification by more than the MD.
Conclusions:
The excellent reliability of V̇O2GXT in addition to the examination of the individual differences between V̇O2GXT and V̇O2verification using the MD indicated that a standalone GXT was sufficient to determine V̇O2max.
... However, this correlation has its limits because to reach a high place in a race ranking, other requirements are needed, such as very good physical [56], tactical and mental training [57], as well as a good biochemical status of the organism. Thus, we can state that a superior VO 2 max value does influence obtaining maximum results during a race in a good way [58], but it does not automatically determine a higher place in the race rankings. ...
Carder, MJ, Scudamore, EM, Savanna, KN, Pribyslavska, V, Bowling, LR, and O'Neal, EK. Retrospective and contemporary predictors of National Collegiate Athletic Association Division I cross-country performance are sex specific. J Strength Cond Res 37(11): 2267–2272, 2023—The purpose of this study was to identify National Collegiate Athletic Association (NCAA) Division I cross-country (XC) performance potential using laboratory-based and field-based parameters and retrospective high school (HS) personal best (PB) data at various distances of current collegiate XC runners. Fifteen female and 17 male NCAA XC runners provided their PB for 5-km (women) and 8-km (men) distances from the previous season. Bivariate correlation and stepwise and hierarchical regression modeling were used to predict XC performance. Single squat jump height and multijump reactive strength index displayed r < 0.27 for both sexes, suggesting lower-body power is a poor predictor of XC performance or masked by other factors of greater importance. Triceps skinfold thickness approached significance ( r = 0.43; p = 0.09) for men but was unrelated to women's performance ( r = −0.05; p = 0.86). HS XC PB neared significance ( r = 0.55, p = 0.054), but no other single or combination of variables reached significance for female runners. Aerobic capacity displayed a moderate to strong relationship ( r = 0.65) for male runners. High school 3,200-m PB for men produced a robust prediction capacity ( r = 0.85; p = 0.005, SEE = ± 0.65 minutes), and predicted 8-km PB within 30 seconds for approximately two-thirds of runners. These outcomes suggest when recruiting HS or transfer athletes, male and female XC runners should not be recruited on the same factors. Women's XC PB is more difficult to predict, but skinfold thickness was statistically the least valuable predictor of all factors.
A regular endurance training program may elicit different adaptations compared to an isolated training method. In this study, we analyzed the effects of 8 weeks of a regular endurance training program on running economy (RE), particularly neuromuscular and biomechanical parameters, in runners of different athletic abilities. Twenty-four male runners were divided into two groups: well-trained (n=12) and recreational (n=12). Both groups completed a 4-min running bout at 13 and 17 km·h-1, respectively, for the recreational and well-trained group, and a 5-jump plyometric test pre-post intervention. During the training program, participants completed low-intensity continuous sessions, high-intensity interval training sessions, and auxiliary strength training sessions. RE, measured as oxygen cost and energy cost, decreased by 6.15% (p=0.006) and 5.11% (p=0.043), respectively, in the well-trained group. In the recreational group, energy cost of running, respiratory exchange ratio, and leg stiffness decreased by 5.08% (p=0.035), 7.61% (p=0.003), and 10.59% (p=0.017), respectively, while ground contact time increased by 3.34% (p=0.012). The maximum height of the 5-jump plyometric test decreased by 4.55% (p=0.018) in the recreational group. We suggest that 8 weeks of regular endurance training leads to an improvement of ~5% in RE in recreational and well-trained runners with different physiological adaptations between groups and few changes in biomechanical and neuromuscular parameters only in recreational runners.
Muscle biopsy samples were obtained from the gastrocnemius of 26 well-trained runners of widely varying ability. Portions of the sample were analyzed for succinate dehydrogenase (SDH) activity and for muscle fiber composition.
$\dot V$
O2 max was determined during uphill treadmill running. Mean values for muscle SDH activity (14.6 U/g), fiber composition (55% slow twitch) and
$\dot V$
O2 max (60.9 ml/kg×min−1) were lower than reported previously for groups of elite and sub-elite runners. The physiological data were consistent with the performance ability of the sample [5∶12, 11∶20 and 36∶40 (min∶s) for 1, 2 and 6 miles, respectively]. Within the sample, performance was most strongly related to
$\dot V$
O2 max (r=−0.84, −0.87 and −0.88 for 1, 2, and 6 miles). There was little relationship between muscle SDH activity and either performance (r=−0.11, −0.14, −0.20 for 1, 2, and 6 miles) or
$\dot V$
O2 max (r=0.23). The relationship between muscle fiber composition and performance was only modestly strong (r=−0.52, −0.54, −0.55 for 1, 2, and 6 miles). The results indicate that the primary determinant of cross-sectional differences in running performance is
$\dot V$
O2 max. Skeletal muscle metabolism apparently contributes little to these cross-sectional differences and may be of much greater importance to variations in performance within an individual.
This study was undertaken to determine the response of
$\dot V$
O2 max and of running performance (805 and 3218 m) to the onset of training in untrained individuals and to an increase in the volume and intensity of training in well trained individuals. In series A,
$\dot V$
O2 max and performances of 12 previously untrained individuals were determined before and after 4 and 8 weeks of training. In series B, performances,
$\dot V$
O2 max and
$\dot V$
O2 submax of 15 previously well trained runners were determined before and after 4 and 8 weeks of controlled training. In series A,
$\dot V$
O2 max increased during the first 4 weeks of training but failed to increase further even in the presence of an increased training load (80 total km for the first 4 weeks, 130 total km for the second 4 weeks). Running performances improved throughout the training period. In series B, neither
$\dot V$
O2 max nor
$\dot V$
O2 submax changed but running performance improved throughout the experimental period. The results indicated that not all of the improvement in running performance subsequent to training is attributable to changes in
$\dot V$
O2 max. Further the results indicate that changes in running economy are not a likely explanation for performance improvement among previously well trained runners. It is suggested that physiological adaptations not integrated in the test of
$\dot V$
O2 max, or improvement in pacing contribute to training induced improvements in running performance.
Muscle biopsies were obtained from the gastrocnemius of 14 elite distance runners, 18 middle distance runners, and 19 untrained men. The middle distance runners were all highly trained, but had significantly slower performance times than the elite runners at distances greater than 3 miles. Fiber composition and mean cross sectional areas were determined from muscle sections incubated for histochemical activity. A portion of the specimen was used to determine succinate dehydrogenase (SDH), lactate dehydrogenase (LDH) and phosphorylase activities. All subjects were tested for maximal oxygen uptake on a treadmill. As previously demonstrated by others, the elite runners' muscles were characterized by a high percentage (79%) of slow twitch (ST) fibers. On the average, the cross sectional area of their ST fibers was found to be 22% larger than the FT fibers (P<0.05). SDH activity of whole muscle homogenates from elite and middle distance runners was 3.4 and 2.8 fold greater, respectively, than that measured in the untrained men. Since the LDH and phosphorylase activities were similar for the runners and untrained men, it appears that training for distance running has little influence on the enzymes of glycogenolysis.
The author presents this book as a supplement to his
Psychometric methods (see
10: 6010). This new text presupposes no previous knowledge of statistics and does not include the emphasis on measurement nor psychophysics which was contained in the previous one. There is also no description of factor analysis, for which the reader is referred to the earlier volume. Within the 14 chapters the author presents the newer work of Fisher and others, such as methods of statistical inference and analysis of variance. Two new chapters, on testing hypotheses, and on predictions and errors of prediction, have been added and include such concepts as the null hypothesis, chisquare distribution, and the use of attributes in statistical prediction. The statistical illustrations are taken from modern psychological research. Exercises are presented after each chapter. Six tables in an appendix and an author and subject index are given. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The present study confirms earlier observations that the musculature of elite distance runners is characterized by a high predominance of ST fibers. Although the percent ST fibers effectively discriminates between good and elite distance runners, fiber composition alone is a poor predictor of distance running success within the group of elite runners. Muscle enzyme measurements suggest that the 11 to 20 miles (17.7 to 32.2 km) of daily training performed by the elite runners produced a significantly greater increase in muscle SDH activity than was observed in the good distance runners, who were running 7 to 11 miles (11.3 to 17.7 km) per day, Although such endurance training enhances the oxidative capacity of the muscle, it apparently has little influence on the enzymes of glycogenolysis.
The aerobic performance of thirteen male ultramarathon and nine female marathon runners were studied in the laboratory and their results were related to their times in events ranging in distance from 5 km to 84.64 km.
The mean maximal aerobic power output (VO2 max) of the men was 72.5 ml/kg·min compared with 58.2 ml/kg·min (p<0.001) in the women but the O2 cost (VO2) for a given speed or distance of running was the same in both sexes. The 5 km time of the male athletes was closely related to their VO2 max (r=−0.85) during uphill running but was independent of relative power output (%VO2 max). However, with increasing distance the association of VO2 max with male athletic performance diminished (but nevertheless remained significant even at 84.64 km), and the relationship between VO2 max and time increased. Thus, using multiple regression analysis of the form: $$\begin{gathered} 42.2 km (marathon) time (h) = 7.445 - 0.0338 \dot V{\text{O}}_{{\text{2 max}}} ({\text{ml/kg }} \cdot {\text{ min}}) \hfill \\ - 0.0303\% \dot V{\text{O}}_{{\text{2 max}}} (r = 0.993) \hfill \\ \end{gathered} $$ and $$\begin{gathered} 84.64 {\text{km (London}} - {\text{Brighton) time (h) = 16}}{\text{.998 }} - {\text{ 0}}{\text{.0735 }}\dot V{\text{O}}_{{\text{2 max}}} \hfill \\ ({\text{ml/kg }} \cdot \min ) - 0.0844\% \dot V{\text{O}}_{{\text{2 max}}} (r = 0.996) \hfill \\ \end{gathered} $$ approximately 98% of the total variance of performance times could be accounted for in the marathon and ultramarathon events. This suggests that other factors such as footwear, clothing, and running technique (Costill, 1972) play a relatively minor role in this group of male distance runners. In the female athletes the intermediate times were not available and they did not compete beyond 42.2 km (marathon) distance but for this event a similar association though less in magnitude was found with VO2 max (r=−0.43) and %VO2 max (= −0.49). The male athletes were able to sustain 82% VO2 max (range 80–87%) in 42.2 km and 67% VO2 max (range 53–76%) in 84.64 km event. The comparable figure for the girls in the marathon was 79% VO2 max (ranges 68–86%). Our data suggests that success at the marathon and ultramarathon distances is crucially and (possibly) solely dependent on the development and utilisation of a large VO2 max.
Maximal oxygen uptake (max VO2) in leg and arm work, succinate dehydrogenase activity (SDH) and percentage of slow twitch fibers (%ST fibers) in M. vastus lateralis (VL), M. gastrocnemius c.l. (GL) and M. deltoideus (D) were studied in 89 athletes practising 11 different sport events. It was found that maximal oxygen uptake correlated positively with %ST fibers and SDH activity in M. VL. The SDH activity and %ST fibers in M. VL correlated also with one another. The results suggest that oxidative capacity of the muscles is not the limiting factor for maximal oxygen uptake. The role of the oxidative capacity of the muscles might be important during submaximal work of long duration and when a relatively small muscle mass is activated (long-distance running). MaxVO2 might be the most important determinant of performance when large muscle mass is activated during maximal work of a duration from several minutes up to 1 h (cross-country skiing).