Appraisal of Cardiorespiratory Fitness Estimation Methods Abstract

9

Appraisalof Cardiorespiratory Fitness Estimation Methods

Abstract

Introduction:TheMaximal Oxygen Consumption (VO2max)depicts the capability to transport and take oxygen during extensiveexercises and it is used to reflect the effectiveness ofcardiorespiratory fitness.

Aim:The main objective of the current study was analyzed and the resultsobtained from incremental Treadmeal Test and Cooper Test withJackson’s predictive equation.

Method:167 (134 males and 33 females) healthy participants from the LeedsMetropolitan University was used as the main population. The studysample comprised on 167 Exercise and Sports students from LeedsMetropolitan University. Among them, females n=34 and males n=133.The average mass was 79.8323±10.41445,average height 1.64±.057,average age was 19.71±.836.Direct and indirect measurements for the VO2maxwerecompared to those obtained from the NASA JSC predictive equation.

Results:The descriptive statistics derived from the three tests illustrated acorrelation coefficient between Jackson predictive equation andIncremental Treadmeal test was 0.4087 while the one obtained forCooper test and NASA was 0.3146. On the other hand, the correlationbetween the predicted and measured value was revealed a strongcorrelation.

Conclusion:NASAis the most appropriate method of estimating the maximum oxygenuptake.

KeyWords: Aerobic Capacity, Cardiorespiratory fitness and non-exercisingVO2maxprediction

Predictiveequations

Differentauthors have provided predictive equations for estimating the VO2max.For instance, Jackson et al. (1990) provided the NASA predictiveequation for the non-existing VO2max estimatethat is usually based on age, weight, height and physical level ofactivities. Jacks et al (2011) define limiting factors that areinvolved with the direct estimation of VO2maxto encompass the logistical issues and the discomfort to theparticipants, meaning that the GXT maximal level of exertion isreached, therefore, increasing the risks associated with adversecardiac events (Dwyer and Shala, 2008).

Researchshows that in order to trigger VO2maxin a person who is asymptomatic, the tests on incremental treadmilltests should take place between 5 and 26minutes. According to Dlugoc(2013), validity is characterized by the steady state exercise forthe treadmill speeds that were over 5.0mph, which was equivalent to(134m.min-1).According to Hamlin et al. (2012) there existed a strong correlationbetween Jackson Predictive Equation and incremental treadmillprotocols (p=0.93). This illustrated the affirmation of the treadmillprotocols at low fitness levels in observing the variability fir theindividuals with an aerobic power of more than 50mL.kg-1min-1(Kedissi, 2005).

Noakes(2001) stated the laboratory protocols to lack ecological validity,hence failing to replicate the specific movement patterns associatedwith the team. On the other hand, field-based procedures enhance areduction in repeatability compared to the measurement of the VO2max.Nevertheless, Guyton and Hall (2007) demonstrated the concurrentvalidity (p≤0.05) with the Cooper 12-minute run denoting a verystrong correlation between the travelled distance travelled withinthose 12 minutes and recording the corresponding VO2max(r=0.9, p=0.001) required to attain the oxygen efficiency consumptionas the exercise continued (Cooper, 1968).

Variousauthors have derived non-exercise equations to predict the VO2max.Inthis research, the non-exercise methods applied the questionnairedata alongside the predictor variables in calculating the VO2maxusing the physical activity rating (PA-R) question to allow theparticipants provide the self-report levels for the related physicalactivity(Hagerman, 1984).

Accordingto Jackson et al. (1990) c a cross-validation analysis of thenon-exercising model(Hirai, 2006), amongst the asymptomatic adultsrevealed that applying the PA-R scores in the non-exercise regressionmodels was critical (r=0.81-0.94, SEE=3.09-5.35mL.kg-1.min-1).On the other hand, Kolata (2007) noted that an increase in the R2with the additional variables such as gender, BMI, age and activitylevel, was critical in predicting the VO2max,Guyton and Hall (2007)) stated that BMI was a valid variable when thenon-exercising protocols were used in predicting the VO2max.

Themain physiological factors that limit VO2maxincluded the pulmonary diffusing capacity that results to inducedincreases in VO2max.Such increases in VO2maxare as a result of high cardiac output instead of the widening of thea-vO2diffthat induced the increases the VO2maxfrom 3.15 to 3.69L.min-1equivalent to a VO2maxincreaseof 8.0%.

Aim

Thisstudy aimed at comparing the maximal running based on the VO2maxprotocolsto the gold standard and Jackson predictive equation to predict thevalidity of the VO2maxestimationtechniques.

ResearchQuestions

Thecurrent research was based on the below research questions

  1. Can NASA predictive equation be correlated to Cooper Test in assessing VO2max?

  2. How is the correlation between NASA predictive equations Incremental Treadmeal Test in assessing VO2max?

  3. Which of the three tests has the strongest correlation between the running based protocols in assessing VO2max?

Researchdesign

Datacollection was conducted at Leeds Metropolitan University and it tookthree weeks. The participants were divided into groups and testedconcurrently on same day for each day for the entire data collectionperiod. The participants were prohibited from taking part ifsuffering from any sickness or injury

Procedure

Beforeundertaking the study, an informed consent was sought (Appendix D).the informed consent contained the information regarding the twotests that the participants were required to complete. A pre-exercisescreening was conducted on compulsory basis while the data collectionwas undertaken under natural conditions. The participants wererequired not to be involved in any strenuous exercise 24 hours priorto the tests. The tests took a total of six weeks. This gave enoughtime to minimize any errors to the changes inVO2maxattributed to the effects of training. This assumption is affirmed bycarter et al. (2007) who a six-week intervention in endurancetraining increased the maximal oygen uptake by 3 to 4 percent. Allthe participants were required to maintain their current level ofactivity in that duration to minimize changes in the VO2maxValues.

Table 1: Statistics for Male and Female Participants

Mean

Gender

Age (Years)

Height (M)

Mass (kgs)

Systolic BP (mmHg)

Diastolic BP (mmHg)

Male (n=134)

20.14±1.133

1.79±.065

79.8323±10.41445

125.07±8.157

72.29±8.963

Female (n=33)

19.71±.836

1.64±.057

61.4382±8.20418

118.74±11.123

73.44±7.178

Total (n=167)

20.05±1.091

1.76±.088

76.0874±12.44254

123.78±9.167

72.53±8.622

AnthropometricMeasurements

Inthese measurements, the stature and body were measured prior totesting exercise when clothed and without shoes. The assessment ofthe stature took place during the inspiration process and was roundedto the nearest 0.1 cm.

HemodynamicParameters

Themeasurement of the blood pressure was done using a cuff andstethoscope (Spirit, England) and mercury sphygmomanometer (Accoson,MK. 3, and England). The measurements were taken when theparticipants were seated with their left arm at the same level withthe heart during which the cuff measurement was in line with thebronchial artery.

Indirectnon-exercising VO2maxPrediction

Theindirect measurement of VO2maxwas carried out done using the Jackson predictive equation. Jacksonhad validated equation for the non-exercisingVO2maxandconsidered the gold standard. The two gender specific equations usedare as shown below.

Theuse of Body Mass Index (BMI) facilitated the assessment of body massin relation to the square of the height in meters (kg)/ (m2).The variables that were used in predicting the VO2maxincluded age (years) and the level of physical activity. Everyparticipant completed the tests both in incremental treadmill testand volitional exhaustion (Ergo ELG2, Woodway, Germany), and CooperTest. This involved continuous recording of the heart rate, with alight weight facemask and headpiece fitted to allow simultaneousbreathing both through the mouth and nose. The participants undertooka standardized -up for 5 minutes while jogging at a rate of 6-10m/sand 0 percent gradient. During this time, males and females began ata speed of 10m/s and 8m/s respectively. Thereafter, their inclinationincreased at 2% for every 2minutes. The expired oxygen and carbondioxide were determined using the gas analysis method (Cortex,Metalyzer 3B, Germany), which was calibrated with using known gasesprior to each test.

Howleyet al. (199) conducted the achievement criteria for VO2maxthe findings showed the standard validity level as (variation ≤2mL.kg-1min-1)with respect to the increments in VO2.

Twelve–Minute Cooper Test

The12-minute Cooper test was conducted on a 400m track during thistest, the subjects were required to cover the greatest distancewithin the 12-minute test period. Every participant was required tohave a Polar Heart Rate Monitor, especially after the 12-minuteperiod had elapsed. All the participants were required to remainactive for a period of 3 to 5minutes. This was to help in recoveryand preventing any venous pooling of the blood. The VO2maxwasestimated using the following formula.

Table 2: secondary Criteria to Assess Maximal Exertion Attainment (Davis, 2006)

VO2max Secondary Criteria

Respiratory Exchange Ratio

≥1.15

Heart Rate

≥90% of the predicted maximal HR (HRmax)

Subjective fatigue &amp volitional exhaustion

RPE 19-20

Incrementaltreadmill test (TR)

Asub-sample of study participants (n = 147) took part in the treadmilltest. The test was performed using ParvoMedics TrueMax 2400 that wasused in measurement of oxygen consumption. The speed of warm-up wasat 4.5 to 7mph, though this depended on relative fitness of theparticipant. After the warm-up, treadmill grade was increased by 3%for the first three minutes, and at the final stage, the speed of thetreadmill was increased by 0.5mph. The speed of the treadmill wasstopped after the participant reached the RPE of 13 to 14 Borg Scaleunits, and terminated after the participant indicated inability tocontinue with the test.

Atrue maximal test resulted when participant reached a VO2plateau characterized by oxygen uptake difference of at most 2.1mL/kgwhen compared to the previous stage with a RER of more than 1.15 anda maximal heart rate of ±10 beats.

StatisticalAnalyses

TheIBM statistics, SPSS was used to perform the statistical analysiswhile the regression plots were done using Microsoft Excel. Thesignificance tests were applied at 95 percent confidence interval andthe expression of the data was either in terms of the mean andstandard deviation. The Kolmogrorov-Smirnoff test was used indetermining normality.

Theinterpretation of the results was based on the following table

‘r’ Value

Interpretation

±0.00-0.19

Very weak

±0.20-0.39

Weak, Small

±0.40-0.59

Moderate

±0.60-0.79

High, Strong

±0.80-0.99

Very Strong

Results

Thecharacteristics of the participants’ were recorded in Table 1.Also, the means were generated and presented in Table 3. The standarddeviation was also obtained and the deviations from VO2maxobtainedusing the predictive VO2maxequations,the incremental Treadmill Test and the Cooper test. .

CorrelationAnalysis

Thiswas carried out to determine the existence of any relationshipbetween the tests.

MeasuredValue vs. Predicted Value

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.512a

.262

.257

6.94197

a. Predictors: (Constant), Predicted VO2max (ml/kg/min)

b. Dependent Variable: Jackson Predictive Equation

Figure1: PredictedMeasure vs. Measured Value VO2max

Itcan be observed from the figure above that the correlationco-efficient, ‘r’, for the predicted VO2maxand the measured VO2maxvalues is 0.5119. This reflects a moderately positive strongcorrelation (r=0.5119, n=167).

12-MinuteCooper Test vs. Jackson Predictive Equation

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.316a

.100

.092

7.82929

a. Predictors: (Constant), Estimated VO2max (ml/kg/min)

Figure2: Weakcorrelation (n=167, r=0.3146) between VO2maxscores for Cooper test vs. Jackson predictive Equation

Fromthe correlation analysis (n=167, r=0.3146). This implies that thereis a small correlation between The Cooper test and Jackson PredictiveEquation cannot be correlated. Also, from the R2value, it can be concluded that 10% of the VO2maxscores obtained using the Jackson predictive Equation remainsunaccounted for by the results obtained from 12-Minute Cooper Test.

ModifiedIncremental Treadmeal vs. Jackson Predictive Equation

Theregression analysis was carried out to determine the correlationcoefficient for the predicted measure of VO2maxand measured VO2max

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.409a

.167

.160

7.52223

a. Predictors: (Constant), Estimated VO2max (ml/kg/min)

b. Dependent Variable: Jackson Predictive Equation

Figure3: ModeratePositive Correlation (n=167, r=0.4087) between scores obtained byusing Modified Incremental Treadmeal vs. Jackson predictive Equationin predicting VO2max

Fromthe r value obtained, it can be concluded that there exists amoderate positive correlation between modified Incremental Treadmealand Jackson Predictive Equation. This is affirmed by the significancelevel of (p≤0.05). On the other hand, the R2value is 0.167, illustrating that 16.3% of the VO2maxscores obtained using the Jackson Equation remains unaccounted for bythe results obtained from Modified Incremental Treadmeal.

SignificanceTests

One-Sample Kolmogorov-Smirnov Test

12- minute Cooper Test

Modified Incremental Treadmeal

Jackson Predictive Equation

Age (Years)

Height (M)

Mass (kegs)

N

153

147

137

167

167

167

Normal Parametersa,b

Mean

55.0331

55.8527

46.6645

20.05

1.76

76.0874

Std. Deviation

6.45488

9.76539

8.05281

1.091

.088

12.44254

Most Extreme Differences

Absolute

.086

.066

.068

.230

.090

.034

Positive

.037

.066

.047

.230

.055

.025

Negative

-.086

-.058

-.068

-.168

-.090

-.034

Kolmogorov-Smirnov Z

1.063

.797

.793

2.973

1.160

.444

Asymp. Sig. (2-tailed)

.208

.549

.555

.000

.136

.989

a. Test distribution is Normal.

b. Calculated from data.

Fromthe significance analysis, the KS=0.797, p=0.549 for ModifiedIncremental Treadmeal, K-S=1.063, p=0.208 for 12-Minute Cooper Testwhile the Jackson Predictive Test has K-S=0.793, p=0.555. From theseresults, Jackson Predictive equation is more significant, followed byIncremental Treadmeal and 12-Minute Cooper Test.

Discussion

Findingsand Implications

Fromthe analysis, it can be established that the correlation coefficientobtained when correlating NASA with Incremental Treadmeal isrelatively higher, 0.4087, than the ‘r’ value obtained bycorrelating the NASA and 12-Minute Cooper Test, 0.3146. This impliesthat since NASA is considered as the most valid and reliable methodof measuring VO2max,then Incremental Treadmeal is significantly correlated to it. The ‘r’values are in accordance to research by Groot (2009) who demonstrateda strong correlation between Incremental Treadmeal with NASAequation.

Moreover,from the Kolmogorov-Smirnoffstatistics, the significance value (p) was comparatively higher inNASA followed by IncrementalTreadmeal then12-MinuteCooper Test.Bruce et al. Had reported a correlation coeffcienct between thepredicted and measure value of 0.94. From the analysis, the r valueobtained from correlating the measured and predicted value was0.5119. The difference is not too high, hence predicting somecorrelation between the measured and predicted value.

Boththe Cooper and Treadmill tests involve running and it is thereforesurprising for the huge difference in when correlated to the NASAresults. The less accurate prediction of the maximum oxygen uptakeusing 12-Minute Cooper test implies that IncrementalTreadmeal should be used instead of 12-minute Cooper test. Accordingto Dwyer and Shala (2008)12-minute Cooper Test normally givesunderestimate values for maximum oxygen uptake.The current study aimed at determining the reliability and validityof the 12-minute Cooper test and Incremental Treadmill tests againstthe Jackson predictive equation in assessment of the maximal oxygenuptake. A number of key findings by Lambert and Leger (1982) wherethey concluded that Incremental Treadmill tests and Cooper tests werevalid and reliable tests for predicting the VO2max.Additionally, Andrew (2007) noted that the Treadmeal IncrementalTests have low underestimates that the 12-minute Cooper tests. Nevertheless, Hayward (2002) contradicts the results obtained in thecurrent research when he said that tests requiring the subjectsperform maximal capacity must involve the aerobic and anaerobiccomponents. If this was true, then the VO2maxobtained can be overestimated because the contribution of anaerobiccomponent may not be known, hence its validity would remainquestionable.

Justas indicated by the results from regression analysis, the aerobiccomponent for the two tests in embedded within the predictiveequation. Hergenroederand Schoene (1989) had established that the major assumption can beon aerobic component affecting the distance travelled. However, ifthe low anaerobic power was the main reason for the differences incorrelation coefficients, then it remains unclear why the resultsobtained for Treadmill tests appeared to have a high correlationcoefficient.

Accordingto Bruce et al. (1991) the correlation coefficient (r) between themeasured and predicted VO2maxis approximately .94 for n=94. On the other hand, Fletcheret al (1990) carried out a comparison of measured and predictedVO2maxand established an average error (predicted) of -0.6 mL·kg−1·min−1when applied in general equation and −2.0 mL·kg−1·min−1when applied for population-specific equations. On the other hand,the 12-MRT by Cooper indicated that different run-walk tests can becorrelated based on the distance travelled within a given period andthe time required to complete the distance. Cooper had reported atest-retest reliability of 0.90. Based on validity, Cooper (1990) hadreported a correlation of 0.9 between the VO2maxand 12-MRT distance. Jessup et al. (1974) found out a low correlationfor the VO2maxand 12-MRT for males at the age of 18 to 23 years. Also, Safrit et al(1998) had reported similar findings to Jessup et al.(1974)

Limitations

Themain limitation of the current research was that the process of thetests was time consuming and high costs were involved. Also, Modifiedtreadmill tests are applied widely in diagnosis of coronary heartdisease hence providing the normative data. However, the method isapplicable to individual having low functionality capacity. Themanual measurement of the pulse rates posed a major drawback. Thismeant that the results of the current study were prone to human bias.Also, despite the fact pre-practice exercises were done prior to themain tests, some participants could not manage to engage in the walkfor continuous periods.

Recommendationsfor Further Research

Itis recommended that the participants be trained thoroughly before thetest. Also, in future, the researchers should consider using moreautomated tools to enhance accuracy of the measurements. In thecurrent research, analysis was only carried out for three methodshowever, the comparison between more than three methods would becritical in making more conclusive recommendations.

Conclusion

Fromthe analysis, it can be concluded that NASA is the more significantand reliable method in Predicting the VO2maxscores. This is followed by Incremental Treadmeal, and finally12-Minute Cooper Test. The results obtained affirmed the research byClemente (2009) who suggested that NASA is the most valid equationfor the athletic populations. Therefore, the objectives of thecurrent research were fulfilled. The findings revealed thatIncremental Treadmeal is strongly correlated to NASA while 12-MinuteCooper Test is moderately correlated to NASA. In overall, it can beconcluded that NASA is the most appropriate method for predictingaerobic capacity in Cardiorespiratory fitness.

References

AndrewM. J. (2007). Middle- and long Distance Running . In: Edward M.Winter, Andrew M. Jones, R.C. Richard Davison, Paul D.Bromley, Tom H.Mercer Sport and exercise physiology testing Guidelines.

Bruce,R.A.(1971). Exercise testing of patients with coronary heart disease:principles and normal standards for evaluation. AnnClin Res (3),pp. 323–332.

Clemente, C. J., Withers, P. C., &amp Thompson, G. G. (2009). Metabolic rate and endurance capacity in Biological. Journal of the Linnean Society 97 (3), pp. 664–676.

Dlugoc, E. M. (2013). Phylogenec Analysis of Mammalian Maximal Oxygen Consumption During Exercise. Journal of experimental Biology 216 (24), pp. 4712-4721.

Dwyer, G. and Shala, E. D (2008). ACSM`s Health-related Physical Fitness Assessment Manual. Baltimore, MD: Lippincott Williams &amp Wilkins.

Fletcher, G.F, Froelicher, V.F. and Hartley, L .(1990). Exercise standards: a statement for health professionals from the American Heart Association. Circulation 82, pp. 2286–2322.

Gagnon, L., &amp Arthus, S. (1999). Familial Aggregation of VO2max Response to Exercise Training. Journal of Applied Physiology 87 (3) , 1003-1008.

Guyton, A., &amp Hall, J. (2011). Textbook of Medical Physiology.

Groot, J. F.D (2009). Treadmill Testing of Children Who Have Spina Bifida and Are Ambulatory: Does Peak Oxygen Uptake Reflect Maximum Oxygen Uptake? Physical Therapy 89 (7), 679-87.

Hagerman, F. (1984). Applied physiology of Rowing. Sports Med 1 (4) , 3030-26.

Hayward, V. (2002). Advanced fitness assessment and exercise prescription. Leeds: Human Kinetics , pp. 56-57.

Henril, S., &amp Preben, K. (2004). Estimation of VO2max from the Ration between HRmax and HRrest- the Heart Rate Ratio Method. European Journal of Application Physiology, pp. 111-15.

Hergenroeder, A. C and Schoene, R. (1989). Predicting Maximum Oxygen Uptake in Adolescents. Archives of Pediatrics and Adolescent Medicine 143(6), 673-77.

Heyward, V. (1988). Advance Fitness Assessment &amp Exercise Prescription.

Hirai, T. (2006). Physical Work Load Affects the Maximum Oxygen Uptake.&quot Industrial Health 44.2 (2006): 250-57. Web.

Jessup G.T., Tolson, H. and Terry, J.W. (1974). Prediction of maximal oxygen intake from the Astrand Ryhming test, 12-minute run, and anthropo-metric variables using stepwise multiple regressions. Am J Phys Med 53, pp. 200–207.

Keddissi, J. I. (2005). The More, the Better: Maximum Oxygen Uptake and Lung Resection.&quot Chest 127 (4), pp. 1092-094.

Kilne, G. (1987). Estimation of VO2max from one mile track walk, gender, age and body weigh. Journal of Medical Science Sports Exercise 19, pp. 253-259.

Kolata, G. (2007). Why Some People Wont Benefit Despit of Exercises. The New York Times , 17.

Léger, L.A. and Lambert, J. (1982). A maximal multistage 20m shuttle run test to predict VO2max`, European Journal of Applied Physiology 49, pp. 1-5.

Noakes, T. (2001). The Lore of Running. Oxford: Oxford University Press

SafritMJ, Costa, M.G. and Hooper, L.M (1988). The validity andgeneralization of distance run tests. CanadaJournal of Sport Science 13,pp. 188–196.

Appendix

AppendixA:Descriptive Statistics

Gender

Age (Years)

Height (M)

Mass (Kgs)

Jackson Predictive Equation

Rockport 1-Mile Walk Test

Queens College Step Test

12-minute Cooper Test

Modified Incremental Treadmeal

Systolic BP (mmHg)

Diastolic BP (mmHg)

Male

Mean

20.14

1.79

79.8323

47.7039

48.8830

45.7183

55.1033

58.8834

125.07

72.29

Std. Deviation

1.133

.065

10.41445

8.01208

6.89117

4.71821

6.49741

8.61758

8.157

8.963

Minimum

19

2

54.00

30.00

37.99

32.80

34.22

34.00

102

48

Maximum

25

2

112.00

72.94

70.80

53.30

68.83

81.09

145

92

Range

6

0

58.00

42.94

32.81

20.50

34.61

47.09

43

44

Female

Mean

19.71

1.64

61.4382

42.4296

39.2585

38.0467

54.7675

44.9613

118.74

73.44

Std. Deviation

.836

.057

8.20418

6.84767

9.45885

12.24909

6.38630

4.41693

11.123

7.178

Minimum

19

2

46.00

25.00

16.52

.00

43.00

35.52

98

60

Maximum

21

2

81.00

53.10

54.89

43.80

69.10

58.60

137

88

Range

2

0

35.00

28.10

38.37

43.80

26.10

23.08

39

28

Total

Mean

20.05

1.76

76.0874

46.6645

46.6448

43.9479

55.0331

55.8527

123.78

72.53

Std. Deviation

1.091

.088

12.44254

8.05281

8.54638

7.74837

6.45488

9.76539

9.167

8.622

Minimum

19

2

46.00

25.00

16.52

.00

34.22

34.00

98

48

Maximum

25

2

112.00

72.94

70.80

53.30

69.10

81.09

145

92

Range

6

0

66.00

47.94

54.28

53.30

34.88

47.09

47

44

Independent Samples Test

Levene`s Test for Equality of Variances

t-test for Equality of Means

F

Sig.

t

df

Sig. (2-tailed)

Mean Difference

Std. Error Difference

95% Confidence Interval of the Difference

Lower

Upper

Age (Years)

Equal variances assumed

.035

.851

1.374

117

.172

.333

.242

-.147

.813

Equal variances not assumed

1.626

49.522

.110

.333

.205

-.078

.745

Height (M)

Equal variances assumed

.949

.332

9.783

117

.000

.143

.015

.114

.172

Equal variances not assumed

10.782

43.602

.000

.143

.013

.117

.170

Mass (Kgs)

Equal variances assumed

2.725

.101

8.732

117

.000

20.47864

2.34522

15.83406

25.12322

Equal variances not assumed

10.053

47.044

.000

20.47864

2.03698

16.38087

24.57640

Jackson Predictive Equation

Equal variances assumed

.025

.874

2.964

117

.004

5.30247

1.78870

1.76004

8.84491

Equal variances not assumed

3.213

42.433

.003

5.30247

1.65053

1.97257

8.63237

12-minute Cooper Test

Equal variances assumed

.014

.907

.087

117

.931

.13085

1.49954

-2.83891

3.10062

Equal variances not assumed

.089

38.551

.930

.13085

1.47689

-2.85755

3.11926

Modified Incremental SRT

Equal variances assumed

12.186

.001

7.630

117

.000

13.90244

1.82206

10.29395

17.51094

Equal variances not assumed

10.505

70.044

.000

13.90244

1.32337

11.26310

16.54179

One Way ANOVA

Sum of Squares

df

Mean Square

F

Sig.

12-minute Cooper Test

Between Groups

2511.223

46

54.592

1.464

.072

Within Groups

2684.581

72

37.286

Total

5195.804

118

Modified Incremental SRT

Between Groups

5228.547

46

113.664

1.308

.152

Within Groups

6258.934

72

86.930

Total

11487.481

118

Tests of Normality

Kolmogorov-Smirnova

Shapiro-Wilk

Statistic

df

Sig.

Statistic

df

Sig.

Age (Years)

.233

119

.000

.782

119

.000

Height (M)

.077

119

.082

.978

119

.049

Mass (Kgs)

.057

119

.200*

.986

119

.262

Systolic BP (mmHg)

.082

119

.048

.980

119

.074

Diastolic BP (mmHg)

.108

119

.002

.975

119

.028

Jackson Predictive Equation

.077

119

.084

.985

119

.199

12-minute Cooper Test

.087

119

.027

.976

119

.030

Modified Incremental SRT

.074

119

.154

.988

119

.353

*. This is a lower bound of the true significance.

a. Lilliefors Significance Correction

AppendixB: NASAJSC Physical Activity Scale

NASAJSC Physical Activity Scale

Do not exercise regularly, i.e.

0

Avoid walking or exertion, e.g. always use elevator, drive whenever possible

Instead of walking.

1

Walk for pleasure, routinely use stairs, occasionally exercise sufficiently to

Cause heavy breathing or perspiration.

Participate regularly in recreation or work requiring modest physical activity,

Such as golf, horseback riding, calisthenics, table tennis, bowling, weight-lifting or yard work.

2

10-60minper week.

3

Over 1 hour per week.

Participate regularly in heavy physical exercise, e.g., running or a comparable

Activity such as brisk walking, indoor biking, swimming, cycling,rowing, skipping rope, running inplace, or engaging in vigorous aerobic exercise such as tennis, basketball, or handball.

4

Run less than1 mile per week or walk lessthan1.3 miles per week or spend

Less than30min per week incomparable physical activity.

5

Run1-5milesper week or walk 1.3-6.9milesper week or spend30-60minper

Week incomparable physical activity.

6

Run6-10milesper week or walk 7-13.9milesperweek or spend1-3hper

Week incomparable physical activity.

7

Run11-15miles per week or walk 14-20miles per week or spend4-6h per

Week incomparable physical activity.

8

Run16-20miles per week or walk 21-26.9 miles per week or spend7-9h per

Week incomparable physical activity.

9

Run21-25miles per week or walk 27-33.9 miles per week or spend10-12hper

Week incomparable physical activity.

10

Run over 25 miles per week or walk over 34 miles per week or spend over 12 h

Per week incomparable physical activity.

AppendixC:Equipment Used During the Analysis

AppendixD:Consent Form

Appraisal of Cardiorespiratory Fitness Estimation Methods Abstract

9

Appraisalof Cardiorespiratory Fitness Estimation Methods

Abstract

Introduction:MaximumOxygen uptake (VO2max)refers to the maximum rate at which oxygen is consumed by the bodyduring the incremental exercises, typically on motorized treadmill.This rate is a reflection of the aerobic physical fitness of aparticular individual.

Aim:The issue on the best equation has been a major contention toestimate maximum energy uptake. Therefore, this research was carriedout to determine effectiveness of RMWT, NASA predictive equation andQCSR in estimating VO2max.

Method:Thesample population was taken from Leeds Metropolitan University andcomprised of 167 participants, 133 males and 34 females. Eachparticipant calculated the non-existing VO2maxusing NASA predictive equation that was developed by Jackson et al.,then QCST and RMWT.

Results:According to the results of the study, the significance level for thevarious tests was as follows for NASA, K-Sis .793 (p=0.555), RMWT K-S is 0.796 (k=0.551) and QCST K-S value is1.364 (p=0.048). On the other hand, the correletaion between NASAand RMWT revealed a strong correlation (r=0.6656) while the NASA andQCST (r=0.528).

Conclusion:Therefore, the results of the current study consurred with theresearch by other authors such as McSweginat al. (1998) who suggested that NASA is the most valid equation forthe athletic populations.

Accordingto Magnan (2013), maximum Oxygen uptake (VO2max)refers to the maximum rate at which oxygen is consumed by the bodyduring the incremental exercises, typically on motorized treadmill.This rate is a reflection of the aerobic physical fitness of aparticular individual. VO2maxis vital in determining the endurance capacity during sub-maximal andprolonged exercise. The increase in intensity of the exercise resultsto a corresponding increase in consumption of oxygen (Basset, 2000).Nevertheless, there is a point that reaches when the intensity of theexercise when the intensity for the exercise increase without acorresponding increase in consumption of oxygen. This point isnormally the VO2max.The aerobic power, maximum uptake of oxygen and aerobic capacityterms are interchangeably used with VO2max.

Inmeasuring VO2max,the physical effort with a duration and intensity sufficient enoughto enhance full taxation of the aerobic energy system is measured(Dlugoc, 2013). This exercise presents the results of a research thatwas carried out to determine the effectiveness of RMWT, NASApredictive equation and QCSR in estimating VO2max.Various authors have proposed different methods in estimating VO2max.From the literature reviewed, most authors supported NASA as the mostappropriate method (Gagnon &amp Arthus, 1999). This was affirmed bythe results of the current study where NASA had the highestsignificance value. This was followed by RMWT and finally QCST.However, the huge differences in QCST as compared to other valueswould have been contributed by the fact that participants werecompelled to walk faster than normal and the method of measuring thepulse rate was too manual.

Ingeneral athletic and clinical testing, such measurement involvesgraded exercise test using a cycle ergometer or treadmill. Thesetools enhance making of progressive measurements while measuring theconcentration of carbon dioxide, oxygen and ventilation (Clemente etal., 2009). The point at which the consumption of oxygen is constantdespite the increase in intensity reflects the VO2max.

Accordingto Hagerman (1984) VO2maxcanbe measured using various methods such as splitting thenon-exercising and exercising estimates where the exercising estimateis split between submaximal and maximal protocols. On the other hand,Sartor proposed the consideration of direct gas analysis duringmaximal running. He argued that this is the most reliable and validmethod of analyzing VO2maxin an individual. Nevertheless, the direct gas analysis protocol isconsiderably expensive and requires specialized equipment.Furthermore, the factor involved is not justifiable, especially forclinical populations with heart problems.

Predictiveequations

Variousauthors have provided predictive equations for the VO2max.For instance, Jackson et al. (1990) produced the NASA predictiveequation for the non-existing VO2max estimatethat is usually based on age, weight, height and physical level ofactivities. In his study, Jackson had sampled 2139 adults where hebelieved that the predictive equation provides a reliable and validestimation of the VO2maxas compared to both the sub-maximal and maximal protocols. On theother hand, Henril and Preben (2004) postulated that while thenon-exercising equations are applicable in clinical settings, theirapplication in athletic populations is normally associated withvalidity issues because of the self-estimated physical activitylevels. Nevertheless, Riebe and Schembre (2011) affirmed that theNASA equation seemed to be the most accurate, most valid and highlyreliable predictor of VO2maxespecially because of the cross validations and corresponding rvalues at 0.82 (Kilne, 1987), and r= 0.78(Jackson et al., 1990).Therefore, the NASA equation was the most valid, particularly forgroup testing. Therefore, in the current study, NASA equation was beused as a criterion method in assessing VO2max.

SubmaximalTesting

TheRMWT proposed by Kilne (1987) has been proven as the valid measurefor VO2max.theauthors devised a predictive equation for the participants at the ageof 30-69years. According to their study, it can be concluded that thetest was a reliable and a valid predictor for this age group.Nevertheless, according to Kolata (2007), the equations by Kilneseemed to be over-predicted, particularly at the lower end of thefitness scale, and the under-predicted upper end. This showed avariance of 8%-23% when compared to other studies completed at thesame time for the same age ranges. Alternatively, Heyward (1988)stated that if there was modification to the physical activity, thenit was possible to use RMWT to accurately predict VO2maxforthe persons aged between 18 and 39 years.

Onthe other hand, Rakov and Bronner (2014) formulated the steps test inpredicting the VO2max during which they that the tests had been comprehensively evaluatedwith other maximal and submaximal tests in order to establish theirvalidity and reliability when used for both females and females ofdifferent age groups. Step testing involves use of portable equipmentwith no calibration and maintenance requirements. The test can becarried out indoors in small spaces and stepping may not be anecessity. However, according to Jacks et al. (2012) the step[process can may not be completely accurate especially when takingpulses after an exercise and the resulting human errors that occurwhile carrying out the calculations.

Purposeof the study

Thesubmaximal and predictive equations have been criticized on theirreliability in estimation of VO2max.Therefore, this study was carried out to compare the RMWT, NASApredictive equation and QCSR in estimating VO2max.

ResearchQuestion

Thecurrent research was sought answers for two main equations. Theseare:

  1. Is there statistically significant relationship between the VO2max scored obtained using the QCST and NASA predictive equation?

  2. Is that statistically significant correlation between VO2max scores obtained using the RMWT and NASA predictive equation?

Sampling

Thestudy sample comprised on 167 Exercise and Sports students from LeedsMetropolitan University. Among them, females n=34 and males n=133.The average mass was76.087kg ± 14kg, average height 176.15±14.71,average age was 20.05 ± 0.86. Screening was done for all theparticipants before testing. They were screened for weight, height,resting heart rate, blood pressure and the current medical ormedication requirements. The participants were required to read theprotocol and give their informed consent.

ResearchDesign

Datacollection was conducted at Leeds Metropolitan University and it tookthree weeks. The participants were divided into groups and testedconcurrently on same day for each day for the entire data collectionperiod. The participants were prohibited from taking part ifsuffering from any sickness or injury.

Procedure

Everyparticipant calculated the non-existing VO2maxusing NASA predictive equation that was developed by Jackson et al.(1990). The step followed by the include measurement of the weightand height in order to enhance calculation of the Body Mass Index (Kg/height (m)2),predicted of the current activity level using the NASA JSC PhysicalActivity Scale, recorded the age as of the test day and entered theall the above variables into gender specific equation. The answerswere recorded on the spreadsheet.

Ineach testing day, the participants were required to participate inQCST and RMWT. The information consent forms were signed to give a goahead on measurements. RMWT was conducted outside on synthetic 400mrunning track. Every participant was required to take sit quietly fortwo minutes then take a fifteen second pulse by pressing the carotidartery using the fingers. The pulse taken was multiplied by four soas to provide a resting pulse. Thereafter, the participants were towalk faster using a measuring wheel for 4.02336 laps. The timewalkerwas used to split into pairs after which the walking member from thepair was set off at intervals of 10 seconds. The participants wererequired to stand still and measure their impulse immediately aftercompleting the walk. The participants were then required to predicttheir VO2maxusing gender specific equation by proposed by Kline at al.

Theparticipants were allowed a 30 min resting period after which theywere required to start the QCST. The process for the resting pulsewas the same as that of RMWT. Thereafter, the participants splittedinto pairs and they used a solid wooden box of height 45.05cm. eachparticipant stepped onto that box using one foot while the restremained on the ground. The participants extended their legs at topand bottom of every step. A metronome was used to dictate the steprate, with women having 22 four step routines/min and men 24step/routine/min. the participants were allowed 15 seconds ofpractice prior to the test. Upon completing the tests, theparticipants stood and measured the pulse in a similar way as forresting prediction. This was recorded and applied to gender specificequation proposed by MaArdle et al (1972). The second pair repeatedthe procedure and recorded their data.

StatisticalAnalysis

MicrosoftExcel application was used to collect data. The collected data wastransferred into IBM SPSS statistics version 22 to help in generationof normality plots for the data and generate correlation analysis.Thereafter, the scatter plots were generated for the VO2maxvalues obtained from the three procedures.

Results

Thetable presents the results on descriptive statistics are presented inthe table below. The descriptive statistics are mean, minimum,maximum and range.

Table 1: Descriptive Statistics

Gender

Age (Years)

Height (M)

Mass (Kgs)

Jackson Predictive Equation

Rockport 1-Mile Walk Test

Queens College Step Test

Male

Mean

20.14

1.79

79.8323

47.7039

48.8830

45.7183

Std. Deviation

1.133

.065

10.41445

8.01208

6.89117

4.71821

Minimum

19

2

54.00

30.00

37.99

32.80

Maximum

25

2

112.00

72.94

70.80

53.30

Range

6

0

58.00

42.94

32.81

20.50

Female

Mean

19.71

1.64

61.4382

42.4296

39.2585

38.0467

Std. Deviation

.836

.057

8.20418

6.84767

9.45885

12.24909

Minimum

19

2

46.00

25.00

16.52

.00

Maximum

21

2

81.00

53.10

54.89

43.80

Range

2

0

35.00

28.10

38.37

43.80

Total

Mean

20.05

1.76

76.0874

46.6645

46.6448

43.9479

Std. Deviation

1.091

.088

12.44254

8.05281

8.54638

7.74837

Minimum

19

2

46.00

25.00

16.52

.00

Maximum

25

2

112.00

72.94

70.80

53.30

Range

6

0

66.00

47.94

54.28

53.30

TheMean for NASA is 47.7039±8.01208,RMWT has 48.8830±6.89117whileQCST has a mean of 45.7183±4.71821.However, as it can be observed from the table, the mean, maximum,range and standard deviation seems to differ for males and females.On the other hand, the maximum age for the population was 25 whilethe minimum age was 19. The maximum height was 2 meters while theminimum was 1.52 meters.

SignificanceTests

Theone-sample Kolmogrov-Smirnov Test was applied to the data collectedin order to help identify the significance of the VO2maxtests.The results are presented in the Table 2 below.

Table 2: One-Sample Kolmogorov-Smirnov Test

Age (Years)

Height (M)

Mass (Kgs)

Jackson Predictive Equation

Rockport 1-Mile Walk Test

Queens College Step Test

N

167

167

167

137

86

52

Normal Parametersa,b

Mean

20.05

2.80

76.0874

46.6645

46.6448

43.9479

Std. Deviation

1.091

13.406

12.44254

8.05281

8.54638

7.74837

Most Extreme Differences

Absolute

.230

.518

.034

.068

.086

.189

Positive

.230

.518

.025

.047

.048

.115

Negative

-.168

-.462

-.034

-.068

-.086

-.189

Kolmogorov-Smirnov Z

2.973

6.696

.444

.793

.796

1.364

Asymp. Sig. (2-tailed)

.000

.000

.989

.555

.551

.048

a. Test distribution is Normal.

b. Calculated from data.

Normally,a Kolmogorov-Smirnoffstatistic reflects the greatest difference in the cuulativeprobabilities across a range of values. Any value exceeding thethreshold implies that the resulting value is not significant. Inthis analysis, the Kolmogorov-Smirnoff Z are for NASA K-S is .793(p=0.555), RMWT K-S is 0.796 (k=0.551) and QCST K-S value is 1.364 (p=0.048).

Figure1: StrongPositive (n=167, r=0.6656) Correlation between VO2maxscores attained from Rockport 1-Mile Walk Test and Jackson predictiveEquation (p≤0.05)

Fromthe correlation equation, the correlation coefficient r= 0.6656. Thisimplies that there exist a strong correlation between the twovariables. This is affirmed by the significance level of (p≤0.05).On the other hand, the R2value is 0.443, illustrating that 44.3% of the VO2maxscores obtained using the NASA equation remains unaccounted for bythe results obtained from RMWT.

Figure2: ModeratePositive(n=167,r=0.528) correlation between VO2Maxscores obtained from QCST and Jackson Predictive Equation (p≤0.05).

Fromthe scatter plot above, the correlation coefficient, r is 0.524. Thisimplies that there exists a moderately strong correlation between thetwo variables. However, the R2value is 0.279 implying that approximately 28 percent of the VO2maxscores obtained using the Queens College step test cannot beaccounted for in NASA equation. This is affirmed by the significancelevel between the two tests (p≤0.05).

Discussion

Findingsand Implications

Fromthe analysis, it can be established that the correlation coefficientobtained when correlating NASA with RMWT is relatively higher,0.6656, that the ‘r’ value obtained by correlating the NASA andQCST, 0.528. This implies that since NASA is considered as the mostvalid and reliable method of measuring VO2max,then RMWT is significantly correlated to it. The ‘r’ values arein accordance to research by Rice (1989) who demonstrated a strongcorrelation between RMWT with NASA equation.

Moreover,from the Kolmogorov-Smirnoffstatistics, the significance value (p) was comparatively higher inNASA followed by RMWT then QCST. Therefore, it can be concluded thatNASA is the more significant and reliable method in testing theVO2maxscores followed by RMWT and finally QCST. The results obtainedaffirmed the research by McSwegin at al. (1998) who suggested thatNASA is the most valid equation for the athletic populations. Heargued that RMWT never stresses aerobic system of individuals havinghigh maximal aerobic system enough to predict VO2maxaccurately. According to research by asset (2000), the discrepanciesin the results could have occurred as a result of some participantsfailing to walk as fast as possible making the line to complete thewalk being very high for the heart rate that was taken at the end ofthe walk. The participants whose aerobic capabilities were high couldwalk at a faster rate without having a high heart rate.

Limitations

Themain limitation of the current study was the manual measurement ofthe heart rate in QCST. This exposed the results obtained to humanerror. Also, giving the instructions to the participants posed amajor danger. Making people walk as fast as possible was quitechallenging. This implied that the participants set off in a higherrate that they could maintain, hence exposing the data toinaccuracies. Nevertheless, this could have been avoiding by ensuringthat the participants get enough time to practice and make any priorpreparations before the actual material day.

Recommendationsfor Further Research

Itwas noted that the variation in QCST could have been caused byinadequate training prior to the exercise. Therefore, it isrecommended that the participants be trained thoroughly before thetest. Also, some measurement methods were done manually using thefinger. In future, specialized equipment will be more favorable inmeasuring the pulse rate. This will help eliminate human bias. Also,the evaluation of three equations only may not be very justifiable ingiving the best equation to conduct the VO2maxestimate. Other methods should be checked and their effectivenessevaluated in future research.

Conclusion

Theobjective of the current paper was to determine the most appropriatemethod of estimating the maximum oxygen uptake. The three mainmethods evaluated were the Jackson Predictive Equation, RMWT andQCST. It was established that NASA had the highest significantresults followed by RMWT and finally QCST. In correlation analysis,NASA and RMWT seemed to be strongly correlated that NASA and QCST.Therefore, it can be concluded that NASA is the most appropriatemethod of estimating the maximum uptake of oxygen, folloed by RMWTand QCST.

Therefore,the objectives of the current research were fulfilled. The findingsrevealed that RMWT is strongly correlated to NASA while QCST ismoderately correlated to NASA. In overall, it can be concluded thatNASA is the most appropriate method for predicting aerobic capacityin Cardiorespiratory fitness.

References

Basset, D. H. (2000). Limiting Factors for Maximum Oxygen Uptake and Determinants of Endurance Performance. Med Science Sports Exercise 32 (1), pp. 70-84.

Clemente, C. J., Withers, P. C., &amp Thompson, G. G. (2009). Metabolic rate and endurance capacity in Biological. Journal of the Linnean Society 97 (3), pp. 664–676.

Dlugoc, E. M. (2013). Phylogenec Analysis of Mammalian Maximal Oxygen Consumption During Exercise. Journal of experimental Biology 216 (24), pp. 4712-4721.

Gagnon, L., &amp Arthus, S. (1999). Familial Aggregation of VO2max Response to Exercise Training. Journal of Applied Physiology 87 (3) , 1003-1008.

Guyton, A., &amp Hall, J. (2011). Textbook of Medical Physiology.

Hagerman, F. (1984). Applied physiology of Rowing. Sports Med 1 (4) , 3030-26.

Henril, S., &amp Preben, K. (2004). Estimation of VO2max from the Ration between HRmax and HRrest- the Heart Rate Ratio Method. European Journal of Application Physiology, pp. 111-15.

Heyward, V. (1988). Advance Fitness Assessment &amp Exercise Prescription.

Kilne, G. (1987). Estimation of VO2max from one mile track walk, gender, age and body weigh. Journal of Medical Science Sports Exercise 19, pp. 253-259.

Kolata, G. (2007). Why Some People Wont Benefit Despit of Exercises. The New York Times , 17.

Noakes, T. (2001). The Lore of Running. Oxford: Oxford University Press

Appendix

Statistics

Age (Years)

Height (M)

Mass (Kgs)

Systolic BP (mmHg)

Diastolic BP (mmHg)

Jackson Predictive Equation

Rockport 1-Mile Walk Test

Queens College Step Test

N

Valid

167

167

167

167

167

137

86

52

Missing

0

0

0

0

0

30

81

115

Mean

20.05

1.76

76.0874

123.78

72.53

46.6645

46.6448

43.9479

Std. Deviation

1.091

.088

12.44254

9.167

8.622

8.05281

8.54638

7.74837

Descriptive Statistics

N

Minimum

Maximum

Mean

Std. Deviation

Age (Years)

167

19

25

20.05

1.091

Height (M)

167

2

2

1.76

.088

Mass (Kgs)

167

46.00

112.00

76.0874

12.44254

Jackson Predictive Equation

137

25.00

72.94

46.6645

8.05281

Rockport 1-Mile Walk Test

86

16.52

70.80

46.6448

8.54638

Queens College Step Test

52

.00

53.30

43.9479

7.74837

Valid N (listwise)

35