The effect of performance feedback on cardiorespiratory fitness field tests

We investigated the effects of performance feedback (PF) on predicting maximal oxygen uptake (VO2 max) using the 20 m Multistage Shuttle Run Test (MST) and 20 m Square Shuttle Test (SST). The agreement between these two field tests in relation to laboratory VO2 max was also examined. Forty healthy males (age: 21.5+/-2.3; BMI: 23.7+/-2.0) randomly performed four indirect VO2 max tests; that is the MST and SST, as well as a modified version of MST (MSTMD) and SST (SSTMD). During MST and SST subjects received PF with respect to both test stage and running pace. In contrast, MSTMD and SSTMD incorporated auditory feedback which solely emitted signals regulating the running pace. Participants also performed a laboratory VO2 max treadmill test (TT). ANOVA demonstrated significant mean predicted VO2 max decrements in both MSTMD (p<0.001) and SSTMD (p<0.05) compared to MST and SST, respectively. In predicting TTVO2 max, the '95% limits of agreement' analysis indicated errors equal to 3.6+/-9.6 and 1.4+/-10.3 ml kg-1 min-1 with coefficients of variation of +/-10.0% and +/-10.9%, for MST and MSTMD, respectively. The corresponding '95% limits of agreement' values for SST and SSTMD were 0.1+/-5.0 and -1.1+/-6.1 ml kg-1 min-1 with coefficients of variation of +/-5.4% and +/-6.7%, respectively. It is concluded that the application of PF leads to superior field testing performances.     

Development of a single-stage submaximal treadmill walking test

An equation was developed to estimate maximal oxygen uptake (VO2max, ml.kg-1.min-1) based on a single submaximal stage of a treadmill walking test. Subjects (67 males, 72 females) aged 20-59 yr completed 4-min stages at 0, 5, and 10% grades walking at a constant speed (2.0-4.5 mph) and then performed a VO2max test. Heart rate and respiratory gas exchange variables were measured during the test. Multiple regression analysis (N = 117) to estimate VO2max from the 4-min stage at 5% grade yielded the following model (R2 = 0.86; SEE = 4.85 ml.kg-1.min-1): VO2max = 15.1 + 21.8*SPEED (mph) -0.327*HEART RATE (bpm) -0.263*SPEED*AGE (yr) + 0.00504*HEART RATE*AGE + 5.98*GENDER (0 = Female; 1 = Male). The constant and all coefficients were highly significant (P less than 0.01). To assess the accuracy of the model in a cross-validation group (N = 22), an estimated VO2max value was obtained using the above model. Estimated VO2max then was regressed on observed VO2max yielding the following equation (R2 = 0.92): ESTIMATED VO2max = 0.15 + 1.03*OBSERVED VO2max. The intercept and slope of this equation were not significantly different from 0 and 1, respectively. For 90.9% of the subjects in the cross-validation group, residual scores were within the range of +/- 5 ml.kg-1.min-1. In conclusion, this submaximal walking test based on a single stage of a treadmill protocol provides a valid and time-efficient method for estimating VO2max.     

A progressive shuttle run test to estimate maximal oxygen uptake.

The purpose of the present study was to examine the validity of using a 20 m progressive shuttle run test to estimate maximal oxygen uptake. Running ability was described as the final level attained on the shuttle run test and as time on a 5 km run. Maximal oxygen uptake (VO2 max) was determined directly for seventy-four volunteers (36 men, 38 women) who also completed the shuttle run test. Maximal oxygen uptake values were 58.5 +/- 7.0 and 47.4 +/- 6.1 ml.kg-1.min-1 for the men and women respectively (mean +/- SD, P less than 0.01). The levels attained on the shuttle run test were 12.6 +/- 1.5 (men) and 9.6 +/- 1.8 (women; P less than 0.01). The correlation between VO2 max and shuttle level was 0.92. The correlation between VO2 max and the 5 km run was -0.94 and the correlation between both field tests was -0.96. The results of this study suggest that a progressive shuttle run test provides a valid estimate of VO2 max and indicates 5 km running potential in active men and women.     

A comparison of the PWC170 and 20-MST tests of aerobic fitness in adolescent schoolchildren

The aim of this study was to compare the validity of two field tests of aerobic fitness for predicting maximal oxygen uptake (VO2max) in a group of adolescent schoolchildren. Twenty four schoolboys (means age = 15.6 +/- 0.6 yr) and twenty four schoolgirls (means age = 15.4 +/- 0.7 yr) underwent three different tests of aerobic capacity, with one week separating each assessment. The test were: (a) VO2max, using a continuous, progressive treadmill protocol, (b) a physical work capacity test at a heart rate of 170 beats per minute (PWC170), and (c) a 20-metre endurance shuttle run (20-MST), using a modified lapscoring protocol. Heart rates were monitored continuously in all tests. Results (means +/- SD) for boys n = 23) and girls (n = 18) respectively were: VO2max, 53.3 +/- 5.9 and 42.6 +/- 5.8 ml.kg-1.min-1; PWC170, 2.84 +/- 0.47 and 1.86 +/- 0.39 w.kg-1; 20-MST, 81.7 +/- 15.9 and 50.4 +/- 12.5 laps. Linear regression of PWC170 and 20-MST on VO2max scores (n = 41), revealed similarly high powers of prediction for both field tests (PWC170 vs VO2max, r = 0.84; 20-MST vs VO2max, r = 0.87), with an indication that the shuttle run test may be preferable for use with girls. In conclusion, the PWC170 and 20-MST field tests both appear to be valid predictors of VO2max in adolescent schoolchildren. However constraints of time and tester expertise favour the 20-MST for the assessment of aerobic capacity in the field.     

Relationship between measured maximal oxygen uptake and aerobic endurance performance with running repeated sprint ability in young elite soccer players

AIM: The aim of the study was to determine the relationships between maximal oxygen uptake (VO(2max)) in a maximal treadmill run and the aerobic endurance performance in the 20-m multistage shuttle run (MST) test, with the performance indices obtained in the running repeated sprint ability (rRSA) test, in elite youth soccer players. METHODS: Thirty-seven adolescent male outfield players performed on separate days and in random order the treadmill run test and the MST, to obtain their measured VO(2max) and aerobic endurance performance (via the number of completed shuttles in the MST), respectively. Players also completed the rRSA test of 6x20-m all-out sprints, interspersed with 20 s of active recovery. RESULTS: There was a significant moderate correlation between measured VO(2max) (in L . min(-1) and mL . kg(-1) . min(-1)) and MST results (r=0.43 and 0.54, P<0.05, respectively). There was no significant correlation between measured VO(2max) and aerobic endurance performance with any of the performance indices in the rRSA test (all P>0.05). CONCLUSION: The moderate association between the measured VO(2max) and MST suggests that both tests were plausibly measuring different aspects of a player's aerobic fitness. The lack of association between measured VO(2max) and aerobic endurance performance in the MST with performance in the rRSA suggests that aerobic fitness per se is poorly associated with performance in the rRSA in elite youth soccer players.     

Estimation of VO2max from a one-mile track walk, gender, age, and body weight

The purpose of this investigation was to explore an alternative field test to estimate maximal oxygen consumption (VO2max) using a one-mile walk test. VO2max was determined in 343 healthy adult (males = 165, females = 178) subjects 30 to 69 yr using a treadmill protocol (mean +/- SD: VO2max = 37.0 +/- 10.7 ml X kg-1 X min-1). Each subject performed a minimum of two, one-mile track walks as fast as possible. The two fastest walks (T1, T2) with elapsed times within 30 s were used for subsequent analyses. Heart rates were monitored continuously and recorded every one-quarter mile. Multiple regression analysis (best sub-sets) to estimate VO2max (l X min-1) yielded the following predictor variables: track walk-1 time (T1); fourth quarter heart rate for track walk-1 (HR 1-4); age (yr); weight (lb); and sex (1 = male, 0 = female). The best equation (N = 174) was: VO2max = 6.9652 + (0.0091*WT) - (0.0257*AGE) + (0.5955*SEX) - (0.2240*T1) - (0.0115*HR1-4); r = 0.93, SEE = 0.325 l X min-1. Comparing observed and estimated VO2max values in a cross-validation group (N = 169) resulted in r = 0.92, SEE = 0.355 l X min-1. Generalized and sex-specific equations to estimate VO2max (ml X kg-1 X min-1) were also generated. The accuracy of estimation as expressed by SEE was similar among the equations. The results indicate that this one-mile walk test protocol provides a valid sub-maximum assessment for VO2max estimation.     

The effect of backward locomotion training on the body composition and cardiorespiratory fitness of young women

This study investigated the effect of a backward training program on the physical and fitness condition of young women. Twenty-six healthy female university students (aged 18 - 23 years) took part in three different baseline tests: body composition, a submaximal treadmill test, and a 20-m shuttle run test. Subjects were divided into a training group (n = 13) and a control group (n = 13). The training group completed a six-week backward run/walk training program. The control group was restricted to their daily activities similar to the four weeks prior to the onset of the baseline tests. The training group showed a significant (p = 0.01) decrease in O(2) consumption during both submaximal forward and backward exercise on the treadmill (32 % decrease during backward and 30 % decrease during forward exercise). A significant (p = 0.01) decrease in percentage body fat (2.4 %), a 19.7 % decrease in the sum of skinfolds (p = 0.001) and significantly (p = 0.013) improved predicted VO(2max) values from the forward 20-m shuttle run test (5.2 %) were also found in the case of the training group. The findings suggest that backward walk/run training improves cardiorespiratory fitness for both forward and backward exercise and causes significant changes in body composition in young women.     

Physiological parameters related to distance running performance in female athletes

The purpose of this study was to investigate the relationship between running pace for the 5 km, the 10 km, and the 16.09 km (10 mile) distances and the following variables: oxygen uptake and treadmill speed at predetermined lactate accumulation points (2.0 and 4.0 mmol.l-1), oxygen uptake (running economy) at three submaximal standardized treadmill speeds (196, 215, and 241 m.min-1), and maximal oxygen uptake. Thirteen moderately to highly conditioned (VO2max = 59.7 +/- 5.3 ml.kg-1.min-1; VO2 at 2.0 mmol.l-1 of plasma lactate = 46.6 +/- 4.1 ml.kg-1.min-1) female runners between the ages of 18 and 33 yr volunteered to participate. All subjects performed the laboratory tests and the 5 km, 10 km, and 16.09 km competitive time trials on an outdoor 5 km course. The correlation coefficients (r) between each race pace and maximal oxygen uptake (VO2max), speed (s) at 2.0 mmol.l-1 plasma lactate accumulation (PLA2s), and speed at 4.0 mmol.l-1 plasma lactate accumulation (PLA4s) ranged between 0.84 and 0.94. The oxygen costs of running at each of the three submaximal paces were correlated moderately with each race pace (r = -0.40 to -0.63). Hierarchal stepwise multiple regression analyses produced equations with two independent variables which explained 94 to 97% of the variability in race performance.     

Effect of high-intensity submaximal work, with or without rest, on subsequent VO2max

PURPOSE: In practice, tests of maximal oxygen uptake (.VO2max) are often preceded by a lactate profile, a highly intense but submaximal exercise bout. The .VO2max response to preceding high-intensity submaximal exercise, with or without a rest period, has not been determined. If .VO2max is limited after a lactate profile, exercise-induced hypoxemia (EIH) may explain the deficit. The purposes of this study were to: 1) examine the effects of high-intensity submaximal exercise, with or without rest, on subsequent .VO2max; and 2) evaluate the role of EIH in causing any observed changes. METHODS: Ten healthy, well-trained, male cross-country skiers (age = 20.5 +/- 4.7 yr, height = 181.6 +/- 6.0 cm, mass = 72.1 +/- 5.7 kg) completed three exercise trials: an incremental run to fatigue (MAX), MAX preceded by a high-intensity submaximal run (lactate profile) and a 20-min rest period (discontinuous protocol [DC]), and MAX preceded by a high-intensity submaximal exercise run with no rest (continuous protocol [C]). .VO2max, minute ventilation, and arterial oxygen saturation were measured throughout, and diffusion capacity was evaluated 2 min postexercise.RESULTS No significant between trial differences were observed, although the difference between .VO2max determined during the MAX trial (62.7 +/- 6.7 mL.kg-1.min-1) and during the DC trial (58.3 +/- 4.4 mL.kg-1.min-1) approached significance (P = 0.059). DC .VO2max responses could be separated into two groups: five responders whose .VO2max suffered during the DC trial (decreased >7.5% from MAX) and five nonresponders, whose .VO2max was unaffected by preceding submaximal exercise and a rest period. Responders showed greater aerobic capacity during the MAX trial. CONCLUSION: .VO2max is significantly reduced in approximately 50% of cross-country skiers when a maximal exercise test is preceded by high-intensity submaximal exercise and a 20 min rest period; the role of EIH in causing these reductions is unclear.     

Metabolic determinants of 1-mile run/walk performance in children

The 1-mile run/walk test is the field test of choice for evaluating maximal aerobic power (VO2max) in school-aged children. The objective of this study was to determine the relative importance of selected metabolic determinants of mile run/walk performance in children 6-14 yr of age. Mile run/walk time (MRWT), VO2max, running economy (VO2 in ml.kg-1.min-1 at 8.05 km.h-1; VO2econ), and the percentage of VO2max utilized at the average mile run/walk speed (%VO2max) were measured in 59 children (33 boys and 26 girls); 27 6-8 yr olds (group 1), 17 9-11 yr olds (group 2), and 15 12-14 yr olds (group 3). Partial correlations between MRWT and VO2max, VO2econ, and %VO2max, holding constant the effects of age and sex, were as follows: group 1: -0.26, 0.03, and -0.82; group 2; -0.43, 0.09, and -0.88; and group 3, -0.60, 0.45, and -0.80. Multiple regression analysis indicated that the combination of the three metabolic measures accounted for 90%, 97%, and 90% of the variance in MRWT in the three age groups, respectively. Standardized regression coefficients for VO2max, VO2econ, and %VO2max in group 1 (-0.66, 0.19, and -0.83), group 2 (-0.45, 0.33, and -0.92), and group 3 (-0.76, 0.27, and -0.50) indicated that the %VO2max utilized at the average mile run/walk speed was the most important determinant of MRWT variance in children 6-11 yr old, whereas VO2max was the most important determinant for children 12-14 yr old. We conclude that the relative importance of the metabolic determinants of the 1-mile run/walk test, as typically administered in the schools, changes with age.     

Interaction of test protocol and horizontal run training on maximal oxygen uptake

Twenty-seven untrained college-age males (mean age = 23.1 yr) volunteered for this 12-wk training study, which investigated potential interactions between training specificity and treadmill protocol specificity. The study was designed to analyze the interaction between a subject's maximal oxygen uptake (VO2max) on an inclined protocol (IP) vs a horizontal protocol (HP) before and after training exclusively on flat terrain. Experimental subjects (E, N = 17) trained by running on flat terrain for 12 wk, 4 d/wk, 37 min/d at an intensity equal to 65 to 85% of their heart rate reserve while control subjects (C, N = 10) remained sedentary. All subjects underwent a minimum of four maximal treadmill tests (two with an IP and two with a HP) prior to training and two maximal treadmill tests (one IP and one HP) post-training. Multivariate analysis of variance and post-hoc t-tests using a pooled variance-covariance matrix were used to analyze the data. Alterations in E, consequent to training, included significant increases in VO2max [mean IP = 53.6 to 58.4 (+8.9%) and mean HP = 51.7 to 56.2 ml. kg-1 . min-1 (+8.7%)]. C showed a significant pre- to post-training decrease on the HP for VO2max [mean HP = 52.4 to 50.7 ml . kg-1 . min-1 (-3.2%)], but showed no significant change on the IP. There was no significant pre- to post-training interaction between protocols for VO2max. It was concluded that the post-training results do not support the concept of protocol specificity when evaluating VO2max in subjects trained exclusively on flat terrain.     

Physiological and technical characteristics of elite young basketball players

AIM: The aim of this study was 2-fold: a) to describe the physiological and technical characteristics of elite young basketball players, and b) to examine the relationship between certain field and laboratory tests among these players. METHODS: Thirteen male players of the junior's Basketball National team (age: 18.5 +/- 0.5 years, mass: 95.5 +/- 8.8 kg, height: 199.5 +/- 6.2 cm, body fat: 11.4 +/- 1.9%, means+/-SD) performed a run to exhaustion on the treadmill, the Wingate test and 2 types of vertical jump. On a separate day, the field tests (control dribble, defensive movement, speed dribble, speed running, shuttle run and dribble shuttle run) were conducted. RESULTS: Maximal oxygen uptake (VO2max) and ventilatory threshold were 51.7 +/- 4.8 ml/kg/min and 77.6 +/- 7.0% VO2max, respectively. Maximum power output was 10.7 +/- 1.3 Watts/kg and mean power (Pmean) 8.0 +/- 0.7 Watts/kg. Counter-movement and squat jump height were 40.1 +/- 3.7 and 39.8 +/- 4.0 cm, respectively. Performance in control dribble (13.70 +/- 0.96 s), speed dribble (4.24 +/- 0.75 s), high intensity shuttle run (27.90 +/- 1.04 s) and dribble shuttle run (29.50 +/- 1.22 s) was correlated with Pmean (r=-0.58, r=-0.62, r=-0.56 and r=-0.73, respectively, p<0.05). Percent body fat was negatively correlated with all the above field tests (r=0.63, r=0.57, r=0.66, r=0.65, respectively, p<0.05). CONCLUSION: These players presented a moderate VO2max and anaerobic power. The significant correlation between Pmean and certain field tests indicates that these tests could be used for the assessment of anaerobic capacity of young basketball players.     

The effect of training specificity on maximal and submaximal physiological responses to treadmill and cycle ergometry

The purpose of this study was to investigate the effect of training specificity during maximal and submaximal treadmill (TM) and bicycle ergometer (BE) exercise. A group of trained runners (RG, no. 7) and trained bikers (BG, no. 7) underwent graded exercise testing on both TM and BE, utilizing the same testing protocol within each exercise mode for both groups. Data for VO2 HR and BP were collected during each 3 min stage. Group by trial ANOVAs followed by Tukey's post hoc analysis, showed no group difference in VO2max, HRmax or BPmax during TM exercise. However, during each of the first four submaximal 3 min stages, VO2 and HR were significantly less (p less than .05) in RG vs BC, with no significant difference in BP. During BE exercise, VO2max was significantly less for both groups compared with TM (RG-59.6 vs 50.1 ml.kg-1.min-1 BS-59.4 vs 55.1 ml.kg-1.min-1) (p less than .05), with BG exhibiting the greater BEmax (p less than .05). RG also had a reduced HRmax during BE exercise (p less than .05). Both groups showed greater BPmax during BE vs TM exercise (p less than .05). Although submaximal VO2 was slightly less during BE for each stage in RG than BG, these differences were not significant as measured either by ml.kg-1.min-1 or l.min-1. Both submaximal HR and BP mirrored the VO2 response, with no significant differences between RG and BG. These data agree with previous studies, showing a greater effect of training specificity during maximal BE than during maximal TM exercise. However, during submaximal exercise, training specificity appear to have a greater effect during TM than BE exercise.     

Physiologic responses to treadmill running in adult and prepubertal males

Little data are available directly comparing physiologic responses to endurance exercise in children and adults. To evaluate age related differences during maximal and submaximal treadmill exercise, physiologic parameters recorded during testing of 20 active prepubertal boys (aged 9-13 years) were compared with values obtained in nonathletic adult males aged 23-33 years. Maximum oxygen consumption (VO2 max) was 57.9 ml.kg-1.min-1 (6.9 SD) in the boys and 48.3 ml.kg-1.min-1 (4.9 SD) in the adults. Running economy examined both as VO2 at a treadmill speed of 9.6 kph and as the slope of linear regression of VO2 at four submaximal speeds was less in boys compared to men when values were expressed per kg body mass. Differences in running economy between the two groups disappeared, however, when related to body surface area. As expected, children had a higher stride frequency at a given treadmill speed, but running stride frequency was unrelated to economy with the two groups. Lower respiratory exchange ratios were observed at maximal and submaximal exercise in the children, which may reflect diminished anaerobic capacity or differences in substrate utilization. These results substantiate the high aerobic capacity previously observed in children and suggest that lower running economy in younger subjects may largely relate to a greater body surface are/mass ratio.     

The 1-mile walk test is a valid predictor of VO(2max) and is a reliable alternative fitness test to the 1.5-mile run in U.S. Air Force males

The purpose of this study was to assess the validity of the 1-mile walk (Rockport Walk Test) as a predictor of VO(2max) and determine whether the 1-mile walk is a reliable alternative to the 1.5-mile run in moderately fit to highly fit U.S. Air Force males. Twenty-four (33.0 +/- 1.5 years) males completed a maximal treadmill VO(2max) (50.3 +/- 1.4 mL/ kg/min), 1-mile walk, and 1.5-mile run. For the 1-mile walk, there were no significant differences between measured and predicted VO(2max) (p = 0.177, r = 0.817). There were no significant differences (p = 0.573) between points scored in the Air Force Fitness Test for the 1-mile walk and 1.5-mile run tests. In conclusion, the 1-mile walk test is a valid predictor of VO(2max) and can be used as an alternative fitness test to the 1.5-mile run in assessing cardiovascular fitness in Air Force males.     

Physiological, anthropometric, and training correlates of running economy.

Potential physiological, anthropometric, and training determinants of running economy (RE) were studied in a heterogeneous group of habitual distance runners (N = 188, 119 males, 69 females). RE was measured as VO2 (ml.kg-1.min-1) during level treadmill running at 161 m.min-1 (6 mph) (VO2-6). Examined as potential determinants of RE were heart rate and ventilation while running at 6 mph (HR6, VE6), VO2max (ml.kg-1 x min-1), % fat, age, gender, height, weight, estimated leg mass, typical training pace, training volume, and sit-and-reach test performance. RE was entered as the dependent variable and the potential determinants as independent variables in zero-order correlation and multiple regression analyses. Zero-order correlation analysis found VO2max, HR6, and VE6 to be significantly, positively correlated with VO2-6 (P < 0.001). Multiple regression analysis, in which the independent effect of each predictor variable was examined, revealed VO2-6 to be positively correlated with VO2max (P < 0.001), HR6 (P < 0.001), VE6 (P < 0.001), and age (P < 0.05) and negatively correlated with weight (P < 0.01). These findings indicate that, in a diverse group of runners, better RE (VO2-6) is associated with lower VO2max, lower submaximal exercise VE and HR, lower age, and greater weight.     

Longitudinal changes in distance-running performance of young males

Longitudinal studies of adolescent males have shown that absolute maximal aerobic power (VO2max) and distance-running performance improve with age, while VO2max expressed relative to body mass remains stable. These earlier studies used subjects that were engaged in distance-run training; therefore, it was not possible to assess the relative importance of growth and/or run training to improved performance. The purpose of this study, therefore, was to quantify longitudinal changes in VO2max, running economy (RE), and distance-running performance in non-run-trained young males. Six subjects were tested at mean ages of 9.9 (T1) and 16.8 years (T2). Statistical tests of mean values revealed that over the 7-year period, relative VO2max remained unchanged (T1, 48.9 ml.kg-1.min-1; T2, 47.8 ml.kg-1.min-1) and RE improved (T1, 234.2; T2, 202.8 ml.kg-1.km-1), 9-min run distance increased (T1, 1637 m; T2, 2115 m), and the estimated percent of VO2max incurred during the 9-min run increased from 85.8% (T1) to 99.5% (T2). It was concluded that the improvement in distance-running performance observed in adolescent boys was not dependent upon run training. In view of the fact that maximal aerobic power remained stable, this change appears to be attributable to better running economy and an ability in runs of a fixed duration to perform at a higher relative work load.     

Maximal and submaximal oxygen uptakes and blood lactate levels in elite male middle- and long-distance runners

Physiological characteristics of elite runners from different racing events were studied. Twenty-seven middle- and long-distance runners and two 400-m runners belonging to the Swedish national team in track and field were divided, according to their distance preferences, into six groups from 400 m up to the marathon. The maximal oxygen uptake (VO2 max, ml X kg-1 X min-1) on the treadmill was higher the longer the main distance except for the marathon runners (e.g., 800-1500-m group, 72.1; 5000-10,000-m group, 78.7 ml X kg-1 X min-1). Running economy evaluated from oxygen uptake measurements at 15 km/h (VO2 15) and 20 km/h (VO2 20) did not differ significantly between the groups even though VO2 15 tended to be lower in the long-distance runners. The running velocity corresponding to a blood lactate concentration of 4 mmol/l (vHla 4.0) differed markedly between the groups with the highest value (5.61 m/s) in the 5000-10,000-m group. The oxygen uptake (VO2) at vHla 4.0 in percentage of VO2 max did not differ significantly between the groups. The blood lactate concentration after exhaustion (VO2 max test) was lower in the long-distance runners. In summary, the present study demonstrates differences in physiological characteristics of elite runners specializing in different racing events. The two single (but certainly inter-related) variables in which this was most clearly seen were the maximal oxygen uptake (ml X kg-1 X min-1) and the running velocity corresponding to a blood lactate concentration of 4 mmol/l.     

Relation of speed of a mile run, maximum energy cost of running, and maximum oxygen consumption: a field study.

OBJECTIVE: To compare the maximum energy cost of running (MECR) estimated from the speed of a mile run and the maximum oxygen consumption (VO2max) with a field step test. METHODS: MECR was defined as the maximum VO2, derived from the equation VO2 = 5.3 mph + 3.9 (ml.min-1.kg-1), when the subject performs a maximal, exhausting run and attains maximum speed. The equation is based on a straight line relation between speed and VO2. In this study MECR was obtained from a mile run and was compared with VO2max by extrapolation using a step test. Both tests were performed in the field. RESULTS AND CONCLUSIONS: The variation in the MECR with VO2max was within +/- 10%. It therefore appears that the speed of a mile run is a good criterion of VO2max or estimated MECR for the measurement of physical fitness, and for the selection, recruitment, and assignment of an individual in field sports.