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1.
Abstract

The purpose of the present investigation was to examine the concurrent and construct validity of the three-mile (4.83 km) run as afield test of aerobic capacity. Subjects included 109 college-aged males whose three-mile run time (M = 1310.31 ± 184.48 s) was measured. Fifty of the subjects were given a maximal treadmill stress test, and their peak oxygen consumption (VO2peak) (M = 54.23 ± 7.08 ml.kg?1.min?1) was measured. The three-mile run was conducted on an outdoor 0.25 mile (0.425 km) track, and split tunes were recorded each 110 yds (100.32 m) for the first and last laps and total time was recorded for laps 2 through 11. The correlation coefficient between the run time and VO2peak was -.58, indicating only moderate concurrent validity for the run as afield test for aerobic capacity. A factor analysis conducted on the split time data revealed a three-factor structure of a stable pace phase, an initial sprint, and a final sprint with the stable pace factor accounting for most of the common factor variance (69%). The three-mile run time was used to discriminate successfully between two known groups of subjects in aerobic capacity. These data provide a degree of support for the construct validity of the three-mile run as afield test of aerobic capacity.  相似文献   

2.
Abstract

The aim of this study was to compare selected physiological variables and performance markers of soldiers from two “elite” units of the British Army. Ten soldiers from each of the two units were recruited for this study (n = 20). All participants completed three tests while carrying a 20 kg backpack load: (1) a maximal treadmill test using the Bruce protocol; (2) a 2 mile backpack run test specific to Unit A on a consistently flat tarmac road; and (3) a 29 km time-trial over hilly terrain typical of a mountainous area used by Unit B for performance assessment. Heart rate, maximal blood lactate concentration and performance (run time) were assessed during all three tests, with peak oxygen uptake also being measured during the maximal treadmill test. Measurements of anthropometry, isokinetic strength and mental toughness (MT48) were also recorded. There were no significant differences in terms of performance markers between the units (P > 0.05). Performance on the maximal treadmill test correlated with performance on the 2 mile backpack run test (r = ?0.57) and 29 km time-trial (r = ?0.66). Performance on the 2 mile backpack run test in turn correlated with 29 km time-trial performance (r = ?0.77), accounting for 59% of the variance. In conclusion, the maximal treadmill test and the 2 mile backpack run test are useful indicators of performance on the arduous hill march and could be employed in the screening and selection of potential recruits.  相似文献   

3.
4.
Abstract

The relative importance of body size, body composition, cardiovascular-respiratory capacity, and running speed in determining individual differences in performance on 600-yd run and mile run tests was investigated using data on 196 children, ages 7 to 12 years. A multivariate, multistage path model was developed in which height, % fat, [Vdot]O2 max (ml/kg FFW · min) and the 50-yd dash time were postulated as determinants of individual differences on the two distance-running tests. These four independent variables accounted for 71% and 66% of the variance in the 600-yd run and mile run, respectively. All four independent variables had significant associations with the two distance runs when the influence of the other independent variables was taken into account. The 50-yd dash time and % fat were found to be the most important determinants of both distance runs. It was concluded that determinants of the 600-yd run and mile run in elementary-school-age children are complex and that individual differences on these tests reflect a number of attributes in addition to cardiovascular-respiratory capacity.  相似文献   

5.
The purposes of this study were to examine the test-retest reliability of the PACER 20-m, multistage shuttle run and to examine the equivalence reliability of the mile run/walk and PACER from both a criterion-referenced and norm-referenced framework. All fourth- and fifth-grade children (N = 266) from one public school were administered two trials of the PACER and one trial of the mile run/walk (mean age = 10.5 ± 0.5 years). The percent of boys that passed the PACER (68%) was similar to the percent of boys that passed the mile run/walk (66%); however, the percent of girls that passed the PACER (96%) far exceeded the percent of girls that passed the mile run/walk (65%). Criterion-referenced reliability was estimated with proportion of agreement (Pa) and modified kappa (Kq) using FITNESSGRAM® (Cooper Institute for Aerobics Research, 1992) standards. Pa = .97 (Kq = .94) for girls and Pa = .82 (Kq = .65) for boys. The high level of agreement for girls was found because of the low criterion-referenced standards, which allowed 99 of 104 girls to pass both trials of the PACER. Criterion-referenced equivalence reliability of the mile run/walk and PACER was moderate for boys (Pa = .83, Kq = .65) and low for girls (Pa = .66, Kq = .33). The low level of classification agreement for girls was also explained by the low standards for the PACER for this age group. Thirty-four percent of the girls that passed the PACER failed the mile run/walk. Norm-referenced test-retest reliability of the PACER was estimated with an intraclass correlation (Rxx) from a one-way analysis of variance model. Reliability estimates were high for two trials (Rxx = .89 for boys and Rxx = .89 for girls) and acceptable for one trial (Rxx = .80 for boys and Rxx = .79 for girls). Pearson correlations between the mile run/walk and PACER were moderate (-.59≤r≤-.67). The moderate correlations between the mile run/walk and PACER and the low criterion-referenced...  相似文献   

6.
少年女子柔道运动员一周大运动量训练期间的机能变化   总被引:1,自引:0,他引:1  
了解一周大运动量训练对少年女子柔道运动员机体代谢和内分泌免疫机能的影响。对少年女子柔道运动员进行1周的大运动量训练,在不同时段测试血清CK、LDH、BUN、T、C和免疫球蛋白等指标。结论为大运动量训练后睾酮、皮质醇、BUN、CK、LDH和白细胞的变化呈现不同变化规律,可以较敏感地反映少年女子柔道运动员训练期的机能状况。  相似文献   

7.
The aim of this study was to compare selected physiological variables and performance markers of soldiers from two "elite" units of the British Army. Ten soldiers from each of the two units were recruited for this study (n = 20). All participants completed three tests while carrying a 20 kg backpack load: (1) a maximal treadmill test using the Bruce protocol; (2) a 2 mile backpack run test specific to Unit A on a consistently flat tarmac road; and (3) a 29 km time-trial over hilly terrain typical of a mountainous area used by Unit B for performance assessment. Heart rate, maximal blood lactate concentration and performance (run time) were assessed during all three tests, with peak oxygen uptake also being measured during the maximal treadmill test. Measurements of anthropometry, isokinetic strength and mental toughness (MT48) were also recorded. There were no significant differences in terms of performance markers between the units (P > 0.05). Performance on the maximal treadmill test correlated with performance on the 2 mile backpack run test (r = -0.57) and 29 km time-trial (r = -0.66). Performance on the 2 mile backpack run test in turn correlated with 29 km time-trial performance (r = -0.77), accounting for 59% of the variance. In conclusion, the maximal treadmill test and the 2 mile backpack run test are useful indicators of performance on the arduous hill march and could be employed in the screening and selection of potential recruits.  相似文献   

8.
Abstract

Using three time intervals (1/2 hr., 1 hr., and 2 hr.) between the eating of the liquid meal and running and for a control run (no eating 31/2 to 4 hr. before running), 10 subjects each ran 10 trials for the 1-mile run. The criterion score was the mean of 10 trials for each of the three time intervals and for the control run. The analysis of data indicated that, according to the requirements of the F ratio, the consumption of the liquid meal (290 calories) 1/2 hr., 1 hr., or 2 hr. prior to running had no adverse effect on the running times for the 1-mile run.  相似文献   

9.
The aim of this study was to compare a batsman's running and turning speed during three runs while wearing either traditional batting pads or one of two models of newly designed cricket batting pads. Fifteen cricketers participated. The running and turning speeds were measured on three different days with players using the three pairs of batting pads for each trial in random order. The weights of the pads were 1.85 kg, 1.70 kg and 1.30 kg for P1, P2 and P3 respectively. Each player had to run three runs (3 × 17.68m), with the times recorded at the completion of each run, as well as the time to cover the distance from 5 m before and after the turn at the end of the first run. The fastest time from two trials for each pair of pads was retained for analysis. An analysis of variance (ANOVA) with repeated measures was used to determine the differences between the mean times of the three trials. The results showed no significant differences between the types of batting pads and the time to complete the run‐three‐runs test (P1 = 10.67 ± 0.48 s; P2 = 10.67 ± 0.43; P3 = 10.69 ± 0.44 s), the turning time (P1 = 2.34 ± 0.18 s; P2 = 2.32 ± 0.18 s; P3 = 2.35 ± 0.19 s) and to complete the third run (P1 = 3.49 ± 0.44 s; P2 = 3.53 ± 0.34 s; P3 = 3.51 ± 0.36 s). Of the 45 trials of three runs used for analysis, P, recorded the fastest time on 16 trials (36%), P2 on 19 trials (42%) and P3 on 10 trials (22%). The results showed no significant differences in the running or turning speeds, although there may be some practical relevance to using the newly designed cricket batting pads.  相似文献   

10.
Running downhill, in comparison to running on the flat, appears to involve an exaggerated stretch-shortening cycle (SSC) due to greater impact loads and higher vertical velocity on landing, whilst also incurring a lower metabolic cost. Therefore, downhill running could facilitate higher volumes of training at higher speeds whilst performing an exaggerated SSC, potentially inducing favourable adaptations in running mechanics and running economy (RE). This investigation assessed the efficacy of a supplementary 8-week programme of downhill running as a means of enhancing RE in well-trained distance runners. Nineteen athletes completed supplementary downhill (?5% gradient; n?=?10) or flat (n?=?9) run training twice a week for 8 weeks within their habitual training. Participants trained at a standardised intensity based on the velocity of lactate turnpoint (vLTP), with training volume increased incrementally between weeks. Changes in energy cost of running (EC) and vLTP were assessed on both flat and downhill gradients, in addition to maximal oxygen uptake (?O2max). No changes in EC were observed during flat running following downhill (1.22?±?0.09 vs 1.20?±?0.07?Kcal?kg?1?km?1, P?=?.41) or flat run training (1.21?±?0.13 vs 1.19?±?0.12?Kcal?kg?1?km?1). Moreover, no changes in EC during downhill running were observed in either condition (P?>?.23). vLTP increased following both downhill (16.5?±?0.7 vs 16.9?±?0.6?km?h?1 , P?=?.05) and flat run training (16.9?±?0.7 vs 17.2?±?1.0?km?h?1, P?=?.05), though no differences in responses were observed between groups (P?=?.53). Therefore, a short programme of supplementary downhill run training does not appear to enhance RE in already well-trained individuals.  相似文献   

11.
Abstract

The purpose of this study was to observe the effects of a progressive aerobic training program on hemoglobin concentration (Hb), hematocrit (Hct), red blood cell (RBC) count, mean RBC size (MCV), and mean corpuscular hemoglobin (MCH) of college women (N = 19). Training consisted of jogging (3 × week) one mile per session (Week 1) with a progressive increase in duration to five miles per session (Week 9). Training intensity elicited heart rates between 165–185 beats per minute. Blood samples were taken before training and after approximately two, five, seven, and nine weeks. Maximal oxygen uptake (ml/kg · min?1) increased significantly during training from 41.2 ± 0.7 ( ± SE) to 44.7 ± 0.7. Initial values of Hb, Hct, RBC count, MCV, and MCH were 14.7 ± 0.13 g/dl, 40.4 ± 0.46%, 4.5 ± 0.5 × 106/mm3, 89.0 ± 1.1/μ3, and 32.4 ± 0.4 μμg respectively. Orthogonal polynominal regression indicated significant decreasing quadratic trends for Hb, Hct, and RBC count, a significant cubic trend for MCV, and no change in MCH during training. Despite the initial trends, values that changed did return to near pretraining levels by the end of the nine-week program. Values for all blood parameters remained within normal ranges throughout the study. These data suggest that although aerobic training of increasing intensity in young women may be accompanied initially by decreases in Hb, Hct, and RBC count and an increase in MCV, these changes are only transitory. If such changes result from RBC destruction rather than hemodilution, the return to hematopoietic balance could impose a draw on body iron stores.  相似文献   

12.
Abstract

Ingesting carbohydrate plus protein following prolonged exercise may restore exercise capacity more effectively than ingestion of carbohydrate alone. The objective of the present study was to determine whether this potential benefit is a consequence of the protein fraction per se or simply due to the additional energy it provides. Six active males participated in three trials, each involving a 90-min treadmill run at 70% maximal oxygen uptake (run 1) followed by a 4-h recovery. At 30-min intervals during recovery, participants ingested solutions containing: (1) 0.8 g carbohydrate · kg body mass (BM)?1 · h?1 plus 0.3 g · kg?1 · h?1 of whey protein isolate (CHO-PRO); (2) 0.8 g carbohydrate · kg BM?1 · h?1 (CHO); or (3) 1.1 g carbohydrate · kg BM?1 · h?1 (CHO-CHO). The latter two solutions matched the CHO-PRO solution for carbohydrate and for energy, respectively. Following recovery, participants ran to exhaustion at 70% maximal oxygen uptake (run 2). Exercise capacity during run 2 was greater following ingestion of CHO-PRO and CHO-CHO than following ingestion of CHO (P ≤ 0.05) with no significant difference between the CHO-PRO and CHO-CHO treatments. In conclusion, increasing the energy content of these recovery solutions extended run time to exhaustion, irrespective of whether the additional energy originated from sucrose or whey protein isolate.  相似文献   

13.
Abstract

We assessed the agreement between maximal oxygen consumption ([Vdot]O2max) measured directly when performing the 20-m shuttle run test and estimated [Vdot]O2max from five different equations (i.e. Barnett, equations a and b; Léger; Matsuzaka; and Ruiz) in youths. The 20-m shuttle run test was performed by 26 girls (mean age 14.6 years, s = 1.5; body mass 57.2 kg, s = 8.9; height 1.60 m, s = 0.06) and 22 boys (age 15.0 years, s = 1.6; body mass 63.5 kg, s = 11.5; height 1.70 m, s = 0.01). The participants wore a portable gas analyser (K4b2, Cosmed) to measure [Vdot]O2 during the test. All the equations significantly underestimated directly measured [Vdot]O2max, except Barnett's (b) equation. The mean difference ranged from 1.3 ml · kg?1 · min?1 (Barnett (b)) to 5.5 ml · kg?1 · min?1 (Léger). The standard error of the estimate ranged from 5.3 ml · kg?1 · min?1 (Ruiz) to 6.5 ml · kg?1 · min?1 (Léger), and the percentage error ranged from 21.2% (Ruiz) to 38.3% (Léger). The accuracy of the equations available to estimate [Vdot]O2max from the 20-m shuttle run test is questionable at the individual level. Furthermore, special attention should be paid when comparisons are made between studies (e.g. population-based studies) using different equations. The results of the present study suggest that Barnett's (b) equation provides the closest agreement with directly measured [Vdot]O2max (cardiorespiratory fitness) in youth.  相似文献   

14.
Abstract

The purpose of this study was to determine the relationship between female distance running performance on a 10 km road race and body composition, maximal aerobic power ([Vdot]O2 max ), running economy (steady-state [Vdot]O2 at standardized speeds), and the fractional utilization of [Vdot]O2max at submaximal speeds (% [Vdot]O2max ). The subjects were 14 trained and competition–experienced female runners. The subjects averaged 43.7 min on the 10 km run, 53.0 ml · kg?1 · min?1 on [Vdot]O2max , and 33.9, 37.7, and 41.8 ml · kg?1 · min?1 for steady-state [Vdot]O2 at three standardized running paces (177, 196, and 215 m · min?1). The mean values for fractional utilization of aerobic capacity for these three submaximal speeds were 64.3, 71.4, and 79.3% [Vdot]O2max , respectively. Significant (p < 0.01) relationships with performance were found for [Vdot]O2max (r = ?0.66) and % [Vdot]O2max at a standardized speed (r = 0.65). No significant (p > 0.05) relationships were found between running performance and either running economy or relative body fat. As with male heterogeneous groups, trained female road racing performance is significantly related to [Vdot]O2max and % [Vdot]O2max , but not related to body composition or running economy. It was further concluded that on a 10 km road race, trained females operate at a % [Vdot]O2max similar to that of their trained male counterparts.  相似文献   

15.
Abstract

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]O2 max). 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 -1 for [Vdot]O2 max, and 48.1 ml · kg -1 · min -1 for steady state [Vdot]O2 running 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]O2 max, 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]O2 max, T(vent) can account for a large portion of the variance in performance during a 10km race.  相似文献   

16.
Abstract

Eight male and eight female runners were matched on performance in a 24.2 km (15 mile) road race (X time ± SD = 115.1 ± 2.2 min for females, 115.8 ± 3.2 min for males). All subjects completed a graded treadmill run during which [Vdot]O 2 and heart rate (HR) were monitored at several submaximal running speeds and at maximal exercise. Blood samples, collected at rest and 3 min after maximal exercise, were analyzed for hematocrit and hemoglobin (Hb), lactic acid (LA) and 2,3-diphosphoglyceric acid (2,3-DPG) concentrations. Body composition was assessed via hydrostatic weighing. Group comparisons revealed that the males were taller, heavier, and higher in Hb than the females (p < .05). The sexes did not differ significantly in percentage of body fat or in [Vdot]O 2 (ml · kg –1 · min –1 ), HR, respiratory exchange ratio, or ventilatory equivalent of oxygen during submaximal running or at maximal exercise (p > .05). 2,3-DPG was higher in the females when expressed relative to Hb (p < .05). These data indicate that female and male distance runners of equal performance levels are very similar in body composition and in metabolic and cardiorespiratory responses to exercise. The higher Hb observed in males may have been offset in part by the females' higher 2,3-DPG/Hb ratio.  相似文献   

17.
Abstract

As with other match analysis systems, ProZone® uses an absolute speed threshold to identify running speeds at “high-intensity”. In this study, we examined the use of an individualized high-intensity speed threshold based on the speed at the second ventilatory threshold (VT2speed) for assessment of the distance run at high-intensity during matches. Ten professional soccer players completed a maximal treadmill test to determine VT2speed. Match data were identified by means of the ProZone® match analysis system. The distances run at high-intensity during matches were calculated using the default value (19.8 km · h?1) and VT2speed. Differences between VT2speed and the default were analysed using a non-parametric median sign test. The distances run at high-intensity were compared with a paired t-test. The median VT2speed was 15 km · h?1 (range 14–16 km · h?1), which was less than the default (P < 0.01). Mean distance run at high-intensity based on the default and VT2speed was 845 m (s = 296) and 2258 m (s = 707), respectively [mean difference 1413 m; P < 0.001 (95% CI: 1037–1789 m)]. The high-intensity running speeds based on the second ventilatory threshold are substantially less than that used as the default within the ProZone® match analysis system, thus the distance run at high-intensity can be substantially underestimated.  相似文献   

18.
Abstract

In this study, we investigated the effect of biological maturation on maximal oxygen uptake ([Vdot]O2max) and ventilatory thresholds (VT1 and VT2) in 110 young soccer players separated into pubescent and post-pubescent groups.. Maximal oxygen uptake and [Vdot]O2 corresponding to VT1 and VT2 were expressed as absolute values, ratio standards, theoretical exponents, and experimentally observed exponents. Absolute [Vdot]O2 (ml · min?1) was different between groups for VT1, VT2, and [Vdot]O2max. Ratio standards (ml · kg?1 · min?1) were not significantly different between groups for VT1, VT2, and [Vdot]O2max. Theoretical exponents (ml · kg?0.67 · min?1 and ml · kg?0.75 · min?1) were not properly adjusted for the body mass effects on VT1, VT2, and [Vdot]O2max. When the data were correctly adjusted using experimentally observed exponents, VT1 (ml · kg?0.94 · min?1) and VT2 (ml · kg?0.95 · min?1) were not different between groups. The experimentally observed exponent for [Vdot]O2max (ml · kg?0.90 · min?1) was different between groups (P = 0.048); however, this difference could not be attributed to biological maturation. In conclusion, biological maturation had no effect on VT1, VT2 or [Vdot]O2max when the effect of body mass was adjusted by experimentally observed exponents. Thus, when evaluating the physiological performance of young soccer players, allometric scaling needs to be taken into account instead of using theoretical approaches.  相似文献   

19.
The aims of this study were: (1) to identify the exercise intensity that corresponds to the maximal lactate steady state in adolescent endurance-trained runners; (2) to identify any differences between the sexes; and (3) to compare the maximal lactate steady state with commonly cited fixed blood lactate reference parameters. Sixteen boys and nine girls volunteered to participate in the study. They were first tested using a stepwise incremental treadmill protocol to establish the blood lactate profile and peak oxygen uptake ([Vdot]O2). Running speeds corresponding to fixed whole blood lactate concentrations of 2.0, 2.5 and 4.0?mmol?·?l?1 were calculated using linear interpolation. The maximal lactate steady state was determined from four separate 20-min constant-speed treadmill runs. The maximal lactate steady state was defined as the fastest running speed, to the nearest 0.5?km?·?h?1, where the change in blood lactate concentration between 10 and 20?min was?<0.5?mmol?·?l?1. Although the boys had to run faster than the girls to elicit the maximal lactate steady state (15.7 vs 14.3?km?·?h?1, P?<0.01), once the data were expressed relative to percent peak [Vdot]O2 (85 and 85%, respectively) and percent peak heart rate (92 and 94%, respectively), there were no differences between the sexes (P?>0.05). The running speed and percent peak [Vdot]O2 at the maximal lactate steady state were not different to those corresponding to the fixed blood lactate concentrations of 2.0 and 2.5?mmol?·?l?1 (P?>0.05), but were both lower than those at the 4.0?mmol?·?l?1 concentration (P?<0.05). In conclusion, the maximal lactate steady state corresponded to a similar relative exercise intensity as that reported in adult athletes. The running speed, percent peak [Vdot]O2 and percent peak heart rate at the maximal lactate steady state are approximated by the fixed blood lactate concentration of 2.5?mmol?·?l?1 measured during an incremental treadmill test in boys and girls.  相似文献   

20.
Abstract

Percent body fat, ratings of perceived exertion and maximal oxygen consumption during a continuous running treadmill test were obtained on 127 high school female cross country runners. These young runners (x 15.6 yrs) were running approximately 25 miles per week at the time of testing. They had an average [Vdot]O2 max of 50.8 ml · min-1 and an HR max of 198.0 bpm. The mean percent body fat, as determined from hydrostatic weighing, was 15.4%. The onset of metabolic acidosis was estimated to occur at 78% of [Vdot]O2 max. A stepwise multiple regression with the 3000 meter run as the dependent variable indicated that max treadmill run time, weight relative [Vdot]O2 max and [Vdot] max entered the equation in that order, yielding an R of 0.67. Both HR and RPE increased with work intensity, but not at equal rates. These high school female runners had higher [Vdot]O2 max's than previously reported for this age group; however, they were considerably below these values reported for national caliber distance runners.  相似文献   

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