S47

Journal of Physical Activity & Health, 2006, 3(Suppl. 2), S47-S57© 2006 Human Kinetics, Inc.

McClain is with the Dept. of Exercise and Wellness, Arizona State University, Polytechnic Campus, 7350 E. Unity Ave., Mesa, AZ 85212-0180. Welk and Ihmels are with the Dept. of Health and Human Performance, Iowa State University, Ames, IA 50011. Schaben is with the Dept. of Exercise Science, Central College, Pella, IA 50219.

Comparison of Two Versions of the PACER Aerobic Fitness Test

James J. McClain, Gregory J. Welk, Michelle Ihmels, and Jodee Schaben

Background: The PACER test is a valid and reliable assessment of aerobic capacity in children. However, many schools lack adequate space to administer the test. This study compared the utility of the standard 20m PACER test with an alternative 15m PACER protocol in 5th and 8th grade students. Methods: A total of 171 students completed both PACER protocols in a counterbalanced design. Agreement between the two protocols was assessed with correlations, repeated-measures ANOVA, and classifi cation agreement into the FITNESS-GRAM®GRAM®GRAM healthy fi tness zones. Results: The difference in estimated VO2max between the two tests was slightly larger for boys (5th grade, 1.32 ml/kg/min; 8th grade, 1.72 ml/kg/min) than girls (5th grade, 0.14 ml/kg/min; 8th grade, 1.11 ml/kg/min), but these differences are probably not of practical signifi cance. Classifi cation agreement was 88% for boys and 91% for girls. Conclusions: Collectively, the results suggest that the 15m and 20m PACER provide similar information about aerobic fi tness in youth. The 20m test is recommended when possible, but the 15m provides a useful alternative for schools with smaller gymnasiums.

Key Words: aerobic capacity, fi eld test, children

Fitness testing is a common component of most physical education programs because it provides schools and teachers with a way to document and track important dimen-sions of health related fi tness.1 It also provides a way to offer feedback to students and parents that may help children develop more active lifestyles. While it is impor-tant to have adequate levels of fi tness in each component of health related fi tness, aerobic capacity (an indicator of cardiovascular fi tness) is generally considered to be the most important fi tness measure due to its association with coronary heart disease risk in adults and chronic disease risk factors in children and adolescents.2

Aerobic capacity can be measured accurately under laboratory conditions using a maximal treadmill or bike-test protocol. Due to the high cost of the equipment and the time required for individual assessment, this type of procedure is not practical for

S48 McClain et al.

school-based fi tness assessments. Field tests allow aerobic capacity to be estimated outside of the laboratory and in group settings such as physical education class. To be effective, fi eld tests must be valid, reliable, easily administered, allow simultaneous assessment, require minimal equipment, and be noninvasive in nature.

The Progressive Aerobic Cardiovascular Endurance Run (PACER) is the rec-ommended test for aerobic capacity in the FITNESSGRAM®FITNESSGRAM®FITNESSGRAM assessment battery.3

The PACER test consists of running a 20-meter shuttle course with 1-minute paced stages at an initial running speed of 8.5 km h–1 with an increasing speed of 0.5 km h–1 per stage.4 The PACER assessment protocol has many advantages over other commonly used fi eld tests of aerobic fi tness such as the mile run. The protocol can be performed inside, which eliminates environmental limitations and infl uences on testing. The PACER test avoids problems with pacing since the tones on the audio CD indicate the required running pace. The design characteristics of the PACER test also provide a more motivational environment for testing.5 A fi nal advantage of the PACER protocol is that the progressive nature allows much of the test to be performed at a sustainable, submaximal effort. Only the fi nal stages require a maximal effort from the participant. These factors help to reduce stress and moti-vational concerns associated with fi tness testing.

The validity of the PACER test has been examined by comparing scores on the test (maximum running speed, number of levels completed, number of laps, or estimated VO2) with measured VO2max from a treadmill-based protocol. The validity has been well supported, as studies have reported correlation coeffi cients ranging from r = 0.69 and r = 0.69 and r r = 0.87.r = 0.87.r 4, 6–9 The reported test-retest reliability of laps performed for the PACER protocol in school-age children is also high, with intra-class reliability coeffi cients of R = 0.82 to R = 0.93.4,5,8,10

The PACER test has been shown to be an effective assessment tool for many physical education programs. However, one problem limits its overall utility: many schools have gyms or physical education classrooms that are less than 20 meters in length. The test could be administered outdoors, but this makes testing contingent on weather. The development of a shorter length PACER protocol would result in a more versatile fi eld test because it would allow the test to be administered in smaller facilities.

The variables included in the PACER’s prediction equation for aerobic capacity are age and maximum running speed.4 By changing the time intervals on the audio CD, it would be possible to create a shorter test (i.e., < 20m) that replicates the key features of the original test. By maintaining the 1-minute intervals and the same running speeds at each level, it should be possible to employ the same prediction equation for estimation of aerobic capacity. However, there are several issues that could infl uence results using a shorter protocol. The number of laps per level has to increase with a shorter distance and this would increase the number of turns. More turns would imply more acceleration/deceleration during the test and this could lead to premature fatigue. In addition, the increased number of laps could potentially result in premature dropout due to boredom. Before a shorter test can be promoted for use in schools, it is important to determine whether the shorter protocol yields similar estimates of aerobic fi tness as the longer version.

This study compared the utility of the standard 20-meter PACER test with an alternative 15-meter PACER protocol in 5th and 8th grade students. Specifi cally, this study compared the aerobic capacity estimates (VO2max) obtained from the two protocols and the classifi cation agreement between protocols for attaining the

Two Versions of the PACER Test S49

Healthy Fitness Zone (the criterion referenced standard in the FITNESSGRAM test battery).11

MethodsParticipants

Students (N = 204) from selected physical education classes in a local school dis-N = 204) from selected physical education classes in a local school dis-Ntrict were recruited to participate in the project. The sample included 82 fi fth-grade students (49 M, 33 F) and 122 eighth-grade students (75 M, 47 F). All aspects of this research were reviewed and approved by the Iowa State University Institutional Review Board before the project was initiated. Informed consent was obtained from parents and assent was obtained from the students prior to testing.

Development of the 15m PACER CD

The goal in the study was to use similar 1-minute levels and the same running speeds in the 15m protocol to allow the use of the same prediction equations. To accomplish this, the same computer program used in developing the 20m PACER CD was used to create the 15m PACER CD. There are some minor differences in actual running speed between the protocols due to the way in which the number of laps per level are computed on the audio CD (see Table 1). The number of seconds per level in the original 20m protocol ranges from 60 to 66 seconds. The compa-

Table 1 Comparison of Laps/Level and Total Laps for the 15m and 20m PACER

Running Laps/Level Total Lapsspeed (kph) Level 20m 15m 20m 15m

8.5 1 7 9 7 9

9 2 8 10 15 19

9.5 3 8 11 23 30

10 4 9 12 32 42

10.5 5 9 12 41 54

11 6 10 13 51 67

11.5 7 10 13 61 80

12 8 11 14 72 94

12.5 9 11 14 83 108

13 10 11 15 94 123

13.5 11 12 15 106 138

14 12 12 16 118 154

14.5 13 13 17 131 171

15 14 13 17 144 188

15.5 15 13 18 157 206

Note: Running speed based on published values from Leger et al. (1988).

S50 McClain et al.

rable values for the 15m protocol were 58 to 65 seconds. The mean difference between running speeds for the fi rst 8 levels is 0.05 ± 0.06 km h–1 and the overall difference for the complete 15-level comparison is 0.12 ± 0.11 km h–1. The speed difference is slightly higher in the upper levels. However, this is not likely to be a major concern, as the majority of schools lacking a 20m physical education facility are elementary schools, and few elementary school students are able to reach the upper levels of the PACER test.

Testing Procedures

Testing was performed during normal physical education classes. Students in the study were already familiar with the PACER protocol, but the purpose and proce-dures for the testing were explained prior to each test. A researcher demonstrated the testing procedure and identifi ed the change of lap and change of level tones on the audio CD. Participants performed the 15m and 20m protocols approximately one week apart in a counterbalanced design by class section. They wore a numbered jersey to assist with recording of results by the research team. Participants completed the testing in groups of 10 or 15 students and a maximum 5:1 subject to recorder ratio was maintained. Participants were encouraged to give maximal effort during testing to ensure an accurate estimate of aerobic capacity for both tests.

Data Processing

A total of 180 students (76 fi fth graders; 104 eighth graders) completed both ver-sions of the PACER test. Observations during the trials suggested that some students did not give equivalent effort on both versions of the test. To avoid error due to incomplete effort, students who had differences of four or more levels between the two assessments were removed from the analyses. There were nine students with differential effort on the two tests. They consisted of three 5th grade boys and six 8th grade boys. There was no apparent pattern between the protocols, with four incomplete effort trials on the 20m protocol and fi ve incomplete effort trials on the 15m protocol. Because the order of administration was counterbalanced in the study, there would likely be no systematic bias introduced by the overall group level estimates of aerobic capacity. However, correlations and classifi cation agreement results would be biased if these data were included. Therefore the data from these students were removed from all analyses. The fi nal sample included the remaining 171 students (5th grade: 37 M, 31 F; 8th grade: 60 M, 43 F) who exhibited similar effort on both tests.

Another issue that could confound the test results is the determination of the participant’s number of completed laps. The FITNESSGRAM test protocol allows FITNESSGRAM test protocol allows FITNESSGRAMstudents to self-select out of the test but also specifi es that students should be stopped if they fail to reach the line for two consecutive tones on the audio CD. For a subsample of participants, two independent observers were used to record student lap numbers to ensure that this information was recorded accurately. Correlations between the primary and secondary recorder’s lap counts were computed for the 15m and the 20m PACER. Primary and secondary recorder data were available for 68 participants doing the 15m version and for 75 participants doing the 20m version. Correlations were high between recorders, with r = 1.0 and r = 1.0 and r r = 0.99 for r = 0.99 for rthe 15m and 20m PACER, respectively. Primary recorder lap count values were used for all further analyses.

Two Versions of the PACER Test S51

Analysis

Means and standard deviations for the number of laps and levels were computed for each test and these are reported separately for both age and gender groups. The estimated VO2max values for each participant were computed using the Leger et al.4 equation: VO2max = 31.025 + (3.238 * max speed) – (3.248 * age) + (0.1536 * max speed * age). Descriptive data were also reported for estimated VO2max and these are also reported separately for each age and gender group.

Differences in VO2max estimates from the two protocols were analyzed using a two-way (age × gender) repeated-measures analysis of variance (ANOVA). The use of a repeated-measures analyses provides a more stringent test of possible dif-ferences since it controls for individual variability in the tests. An alpha level of 0.05 was used to evaluate the signifi cance of the interaction term and the main effects.

Correlations were computed between the scores from both tests to provide an indication of overall agreement between the two protocols. Correlations were computed for laps, levels, and estimated VO2max. Values are reported separately for each age and gender group. A predetermined criteria level of 0.8 was used to designate good agreement between the two tests.

Bland-Altman plots were used to examine the agreement between the two assessments across the range of VO2max estimates. The Bland-Altman plots display the mean of the 15m and 20m VO2max estimate for an individual on the X-axis and the difference between the estimates (20m–15m) on the Y-axis. Correlations between data points on the Bland-Altman plots were used to determine whether there was any form of systematic bias across the range of fi tness levels.

Classifi cation agreement for achieving the FITNESSGRAM criterion referenced FITNESSGRAM criterion referenced FITNESSGRAMstandards were computed using 2 × 2 contingency tables. Participants were classi-fi ed into either Needs Improvement (NI) or Healthy Fitness Zone (HFZ) categories. Percent correct classifi cations were computed as a descriptive statistic. Kappa values were also reported to provide an overall indicator of agreement after adjusting for the agreement that would occur simply due to chance.

ResultsDescriptive statistics for the participants are presented in Table 2. The overall Ftest for the repeated-measures ANOVA test was signifi cant, F(1, 167 = 15.7), p< .001. The main effect for gender was signifi cant (p< .001. The main effect for gender was signifi cant (p< .001. The main effect for gender was signifi cant ( < 0.05), with boys scoring higher on both the 15m PACER and 20m PACER test. The age main effect was not signifi cant (pnot signifi cant (pnot signifi cant ( > .05), but the values for the 8th graders were slightly higher than for the 5th graders.

The primary comparisons of interest were with the possible differences between the two PACER tests. There was a signifi cant gender-by-test interaction, F(1, 167) = 4.20, p < .042, and this was due to differences in the test comparisons for boys and girls. The difference in estimated VO2max between the two tests was slightly larger for boys (5th grade, 1.32 ml/kg/min; 8th grade, 1.72 ml/kg/min) than for girls (5th grade, 0.14 ml/kg/min; 8th grade, 1.11 ml/kg/min). The main effect for test was also signifi cant but the effect sizes for the actual differences were small (<0.30) and probably not of practical signifi cance.

The correlations between laps, levels, and VO2 estimates from the two tests are presented in Table 3. Correlations between VO2max estimates were slightly higher for boys (r = 0.79) than for girls (r = 0.79) than for girls (r r = 0.67). Correlations were higher for r = 0.67). Correlations were higher for r

S52 McClain et al.

Table 2 Descriptive Statistics on Laps, Levels, and VO2max Estimates by Gender and Grade Level for the 15m and 20m PACER

Male Female(n) Mean SD (n) Mean SD

5th Grade

P15 Laps 37 33.84 15.69 31 31.81 16.59

P20 Laps 37 31.24 12.93 31 23.61 10.75

P15 Levels 37 3.81 1.30 31 3.52 1.45

P20 Levels 37 4.35 1.53 31 3.45 1.28

P15 VO2 (ml/kg/min) 37 44.33 3.40 31 43.7 3.78

P20 VO2 (ml/kg/min) 37 45.65 3.96 31 43.56 3.25

8th Grade

P15 Laps 60 55.02 21.54 43 38.16 14.96

P20 Laps 60 49.07 23.43 43 32.6 13.93

P15 Levels 60 5.47 1.67 43 4.07 1.33

P20 Levels 60 6.10 2.33 43 4.49 1.53

P15 VO2 (ml/kg/min) 60 43.64 4.32 43 40.08 3.31

P20 VO2 (ml/kg/min) 60 45.36 6.01 43 41.19 3.95

Note: P15 = 15m PACER; P20 = 20m PACER.

Table 3 Pearson Correlations Between Laps, Levels, and VO2max Estimates by Gender and Grade Level for the 20m and 15m PACER

Boys Girls

5th Grade

Laps P20 vs. P15 0.58 0.54

Level P20 vs. P15 0.56 0.48

VO2 P20 vs. P15 0.61 0.53

8th Grade

Laps P20 vs. P15 0.91 0.83

Level P20 vs. P15 0.87 0.74

VO2 P20 vs. P15 0.85 0.71

Note: Correlations signifi cant at the p < 0.01 level.

Two Versions of the PACER Test S53

the 8th grade students (M, r = 0.85; F, r = 0.71) than for 5th grade students (M, r = 0.71) than for 5th grade students (M, r r= 0.61; F, r = 0.53). r = 0.53). r

Bland-Altman plots were used to examine agreement between tests across the range of fi tness levels. Separate graphs were produced for each of the four gender-by-grade comparisons. The plots are shown in Figures 1 and 2. The solid line depicts the mean difference in the two tests while the dotted lines show the boundaries for the 95% confi dence interval. Nearly all of the data points fell within the 95% confi dence intervals. Correlations between the individual means and differences in VO2max estimates showed a signifi cant correlation of r = 0.54 for 8th grade boys, r = 0.54 for 8th grade boys, r

Figure 1A and 1B — Bland-Altman plots for 5th grade girls (A) and boys (B).

S54 McClain et al.

suggesting that for this subsample, less fi t individuals performed better in the 15m test and more fi t individuals performed better in the 20m test. Correlations for the 8th grade girls, 5th grade boys, and 5th grade girls were not signifi cant, indicating no fi tness related bias between protocols in the remaining subsamples.

Classifi cation agreement between the 15m and 20m test was examined by look-ing at passing rates, based on achieving the FITNESSGRAM criterion referenced FITNESSGRAM criterion referenced FITNESSGRAMstandards for VO2max. Classifi cation agreement and kappa statistics are presented in the 2 × 2 contingency table shown in Table 4. Classifi cation agreement for age and gender groups ranged from 85% to 93%. The misclassifi cation was evenly

Figure 2A and 2B — Bland-Altman plots for 8th grade girls (A) and boys (B).

Two Versions of the PACER Test S55

Tab

le 4

C

lass

ifi ca

tio

n A

gre

emen

t fo

r R

each

ing

th

e H

ealt

hy

Fit

nes

s Z

on

e b

y G

end

er a

nd

Gra

de

Lev

el f

or

the

20m

an

d 1

5m P

AC

ER

5th

Gra

de B

oys

5t

h G

rade

Gir

ls

HFZ

P15

H

FZP1

5

HFZ

P20

NI

HFZ

Tot

alH

FZP2

0N

IH

FZT

otal

NI

% (

n)10

.81

(4)

2.7

(1)

13.5

(5)

NI

% (

n)0.

0 (0

)6.

5 (2

)6.

5 (2

)

HFZ

% (

n)5.

4 (2

)81

.1 (

30)

86.5

(32

)H

FZ %

(n)

6.5

(2)

87.1

(27

)93

.6 (

29)

Tot

al %

(n)

16.2

(6)

83.8

(31

)10

0.0

(37)

Tot

al %

(n)

6.5

(2)

93.6

(29

)10

0.0

(31)

Kap

pa v

alue

% A

gree

men

t

% A

gree

men

t

% A

gree

men

tK

appa

val

ue

%

Agr

eem

ent

0.63

*

91.9

NA

87.1

8th

Gra

de B

oys

8t

h G

rade

Gir

ls

HFZ

P15

H

FZP1

5

HFZ

P20

NI

HFZ

Tot

alH

FZP2

0N

IH

FZT

otal

NI

% (

n)21

.7 (

13)

5.0

(3)

26.7

(16

)N

I %

(n)

7.0

(3)

2.3

(1)

9.3

(4)

HFZ

% (

n)10

.0 (

6)63

.3 (

38)

73.3

(44

)H

FZ %

(n)

4.7

(2)

86.1

(37

)90

.7 (

39)

Tot

al %

(n)

31.7

(19

)68

.3 (

41)

100.

0 (6

0)T

otal

% (

n)

11.6

(5)

88.4

(38

)10

0.0

(43)

Kap

pa v

alue

% A

gree

men

t

% A

gree

men

t

% A

gree

men

tK

appa

val

ue

%

Agr

eem

ent

0.64

*

85.0

0.68

*

93.1

Not

e: H

FZP2

0 =

Hea

lthy

Fitn

ess

Zon

e fo

r 20

m P

AC

ER

; HFZ

P15

= H

ealth

y Fi

tnes

s Z

one

for

15m

PA

CE

R; N

I =

nee

ds im

prov

emen

t; H

FZ =

H

ealth

y Fi

tnes

s Z

one

clas

sifi c

atio

n; N

A =

Val

ue c

ould

not

be

corr

ectly

com

pute

d du

e to

dat

a di

stri

butio

n.

*Sig

nifi c

ant a

t p <

0.0

01

S56 McClain et al.

distributed for girls, but boys were more likely to pass the 20m than the 15m. Eight boys passed the 20m test and failed the 15m test, while only four boys passed the 15m test and failed the 20m test.

DiscussionThis study examined the utility of a 15m version of the well-established 20m PACER test. The 15m PACER protocol was designed to maintain the critical properties of the original 20m PACER test establish by Leger et al.4 The results suggest that the 15m protocol yields similar information about aerobic fi tness as the well-established 20m protocol. The differences in VO2max estimates between the 15m protocol and 20m protocol were generally small and not of much practical signifi cance. The dif-ferences varied somewhat by grade and gender (range: 0.7 to 1.8 ml/kg/min), but the effect sizes of the differences for all comparisons were less than 0.30.

The differences in estimates of aerobic capacity from the two versions of the PACER are comparable to differences that are evident between other fi eld tests of fi tness in children. Mahar et al. examined differences between VO2max estimates for the 20m PACER and the Mile Run in 266 4th and 5th grade students.10 Dif-ferences of 0.9 and 1.6 ml/kg/min were reported for boys and girls, respectively. Recent work in our laboratory reported differences between VO2 max estimates for the 20m PACER and the Mile Run in 473 7th and 8th grade students.12 Differences of 1.6 and 1.8 ml/kg/min were reported for boys and girls, respectively. The similar differences between the 15m and 20m protocols indicate that the two versions are at least as similar as comparisons between the PACER and the Mile Run.

The increased number of laps per level and the proportionate increase in the number of turns in the 15m protocol were considered as potential limitations to the utility of the modifi ed assessment. However, the small differences in VO2max estimates between protocols suggest that the modifi cation to the protocol had little effect on the functional performance of the fi eld test. The utility of the 15m pro-tocol is further supported by the balanced distribution of difference scores on the Bland-Altman plots. The only plot that exhibited a tendency toward differential test performance by fi tness level was for the 8th grade boys.

The 8th grade boys with higher fi tness levels demonstrated better performance on the 20m protocol compared to the 15m protocol. It is possible that early with-drawal due to boredom contributed to this trend, but it could also have been due to other factors such as fatigue from turns. The 8th grade boys with lower fi tness levels performed better on the 15m protocol than the 20m protocol. This may be the result of a psychological perception that the shorter length protocol required less work or was easier than the longer length protocol.

The impact of any potential boredom withdrawal at higher levels of the 15m PACER does not signifi cantly impact the overall utility of the test. The decision to use the 15m PACER protocol would likely be driven by the type of physical education facilities available to teachers. The majority of smaller facilities that lack adequate room to utilize the 20m PACER are located in elementary school buildings. Children in these schools likely would not reach higher lap counts where turns or boredom could have an impact on test performance. Because the differences appear to be larger among the older sample, it is prudent to recommend the use of the 20m protocol if space permits.

Two Versions of the PACER Test S57

One potential limitation of this study was the lack of a laboratory-based criterion test. However, the validity of the PACER assessment in school-age individuals has been well established in the literature. Leger et al. demonstrated a moderate correla-tion (r = 0.71) between predicted VOr = 0.71) between predicted VOr 2max from the 20m PACER with measured VO2max by retro extrapolation of the O2 recovery curve in boys and girls ages 8 to 18.4 Several other studies, with samples comparable to the present study, have reported signifi cant correlations between cycle or treadmill measured VO2max and either maximum running speed or laps.6,7,8 The overall correlations in these studies ranged from r = 0.69 to r = 0.69 to r r = 0.87.r = 0.87.r

In conclusion, both the 15m and 20m PACER protocols provide similar information about aerobic capacity in students. The differences between aerobic capacity estimates from the 15m and 20m PACER protocols found in the present study are similar to differences typically found in studies comparing other fi eld-based aerobic capacity estimates such as the 20m PACER and the Mile Run. The results of the study suggest that the 15m PACER protocol could be used in place of the 20m PACER protocol when available facilities cannot accommodate the longer testing protocol.

References 1. National Association for Sport and Physical Education. Moving Into the Future National

Standards for Physical Education. 2nd ed. Reston, VA: NASPE Publications; 2004. 2. Cureton KJ, Plowman SA. Aerobic capacity assessments. In: Welk GJ, Morrow J, Falls

H, eds. FITNESSGRAM Reference Guide. Dallas, TX: The Cooper Institute; 2001. 3. Meredith MD, Welk GJ. (Eds). FITNESSGRAM Test Administration Manual. Cham-

paign, IL: Human Kinetics; 2004 4. Leger LA, Mercier D, Gadoury C, Lambert J. The multistage 20 metre shuttle run test

for aerobic fi tness. J Sports Sci. 1988; 6:93-101. 5. Vincent SD, Barker R, Clarke M, Harrison J. A comparison of peak heart rates elicited

by the 1-mile run/walk and the Progressive Aerobic Cardiovascular Endurace Run. Res Q Exerc Sport. 1999; 70:75-78.

6. Van Mechelen W, Hlobil H, Kemper HCG. Validation of two running tests as estimates of maximal aerobic power in children. Eur J Appl Physiol. 1986; 55:503-506.

7. Boreham CAG, Paliczka VJ, Nichols AK. A comparison of the PWC170 and 20-MST tests of aerobic fi tness in adolescent schoolchildren. J Sports Med Phys Fitness. 1990;30:19-23.

8. Liu NY-S, Plowman SA, Looney MA. The reliability and validity of the 20-meter shuttle test in American students 12 to 15 years old. Res Q Exerc Sport. 1992; 63:360-365.

9. Mahoney C. 20-MST and PWC170 validity in non-Caucasian children in the UK. Br J Sports Med. 1992; 26:45-47

10. Mahar MT, Rowe DA, Parker CR, Mahar FJ, Dawson DM, Holt JE. Criterion-referenced and norm-referenced agreement between the mile run/walk and PACER. Meas Phys Ed Exerc Science. 1997; 1:245-258.

11. Chun DM, Corbin CB, Pangrazi RP. Validation of criterion-referenced standards for the mile run and progressive aerobic cardiovascular endurance tests. Res Q Exerc Sport. 2000; 71:125-34.

12. Welk GJ, McClain JJ, Schaben JA, Mahar MT. Method agreement between two fi eld measures of aerobic fi tness in youth. Med Sci Sports Exerc. 2004; 36:S134.

Note: Data were collected as part of a Masters Degree research project completed by the fi rst author while at Iowa State University.