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Committee on Fitness Measures and Health Outcomes in Youth; Food and also Nutrition Board; Institute of Medicine; Pate R, Oria M, Pillsbury L, editors. Fitness Measures and Health Outcomes in Youth. Washington (DC): National Academies Press (US); 2012 Dec 10.
Committee on Fitness Measures and also Health Outcomes in Youth; Food and also Nutrition Board; Institute of Medicine; Pate R, Oria M, Pillsbury L, editors.
Although tbelow is a renowned association in between cardiorespiratoryendurance and also health and wellness outcomes in adults, the measurement ofcardiorespiratory endurance in youth and also of its connection to healthoutcomes is fairly new to the literature. The committee"s reviewrevealed clear relationships in between cardiorespiratory endurance and severalhealth hazard factors, consisting of adiposity and also cardiometabolic threat determinants.Other studies allude to a potential relationship in between cardiorespiratoryendurance and other, less studied threat determinants, such as those related topulmonary function, depression and positive self-principle, and also bonewellness.
Limitations of the researches reviewed by the committee relate mainly to thearchitecture of the researches, specifically the absence of evaluation of the independentimpact of cardiorespiratory endurance on health. A paucity of studiesdiscover the results of numerous potential modifiers, such as age, sex,body composition, maturation status, and also ethnicity, on performance on thevarious tests of cardiorespiratory endurance. While such impacts have actually beensuggested in the previous, the committee can draw no conclusions based on theproof reregarded.
The cardiorespiratory endurance tests many generally associated with apositive change in a wellness marker are the shuttle run and tests conductedthrough the treadmill and cycle ergometer. Available evidence suggests thatthese 3 kinds of tests demonstrate acceptable validity and also reliability.The wellness markers a lot of commonly assessed are related to body weight oradiposity and also cardiometabolic danger factors. Based on its connection tohealth and wellness, and also its relicapability, validity, and feasibility, a timed orsteady shuttle run, such as the 20-meter shuttle run, is appropriatefor measuring cardiorespiratory endurance in youth. If the test is to beadministered in a setting with space limitations (e.g., a mobile test centerfor a national survey), a submaximal treadmill or cycle ergometer testneed to be supplied. The shuttle run is beneficial once there are timeconstraints and when cost may be a problem, such as in colleges and also othereducational settings. Although the evidence for a connection betweendistance/timed runs and health is insufficient at this time, this type oftest is valid and trustworthy and could be an different in colleges and othereducational settings.
Until more information are gathered through which to establish criterion-referencedcut-points (cutoff scores), interim cut-points corresponding to the lowest20th percentile of the circulation of cardiorespiratory endurance have to beused to translate outcomes of all cardiorespiratory endurance tests and todetermine whether people are at danger of negative health outcomes.
Cardiorespiratory endurance has actually been well-known as a crucial componentof physical fitness throughout the background of the area. This chapter presentsthe committee"s review of the scientific literary works that explores therelationship in between particular field tests of cardiorespiratory endurance andhealth outcomes in youth. The committee"s references for theselection of fitness tests are based primarily on a substantial review of theliterary works offered by the Centers for Disease Control and also Prevention (CDC)defined in Chapter 3. In makingits referrals, the committee taken into consideration not just the proof for arelationship to health and wellness, yet also the clinical integrity (reliability andvalidity) of putative health-related tests, and also the administrativefeasibility of implementing these tests. After presenting these outcomes, thechapter uses guidance for setting interim cut-points (cutoff scores) for theselected tests. The last area presents conclusions. Recommendationsabout particular tests for measuring cardiorespiratory endurance for nationalsurveys and also in colleges and other educational settings are found in Chapters 8 and 9, respectively. Future research needsare addressed in Chapter 10.
Cardiorespiratory endurance is the capability to performlarge-muscle, whole-body exercise at modeprice to high intensities forextended periods of time (Saltin,1973). Numerous terms have actually been used to denote this component ofphysical fitness, consisting of aerobic fitness andaerobic capacity. These terms are essentiallyassociated via cardiorespiratory endurance, which is the term offered in thisreport. Forms of exercise that depend on cardiorespiratory endurance includevigorous distance running, swimming, and also cycling. This fitness componentlikewise affects a person"s ability to perform, without undue fatigue,much less intense, continual whole-body tasks, such as bdanger walking, stairclimbing, and house chores. People via great levels of cardiorespiratoryendurance can perdevelop large-muscle, whole-body exercise at high intensityfor at leastern modeprice durations prior to experiencing fatigue, and also they cancomfortably perdevelop light- to moderate-intensity exercise for extendeddurations.
Cardiorespiratory endurance relies on the body"s capability to supportskeletal muscle activity via high prices of aerobic metabolism. Thecapacity to develop energy at high prices with aerobic metabolism duringexercise depends on 3 physiologic functions: (1) transport of oxygenfrom the environment to the energetic muscles with the actions of thecardiorespiratory device, (2) usage of oxygen in the aerobic metabolicprocess in the cells of the active muscles, and (3) removal of wastecommodities. People via high levels of cardiorespiratory endurance typicallyhave very functional cardiorespiratory devices (i.e., heart, lungs, blood,blood vessels), and also their skeletal muscles are well adjusted to the usage ofoxygen in aerobic metabolism.
Higher levels of cardiorespiratory endurance have actually been linked via a widerange of health benefits in adults, including a lower hazard of cardiovasculardisease (Arraiz et al., 1992;Blair et al., 1989; Sandvik et al., 1993), type 2diabetes (Colberg et al.,2010), hyperstress (Blair etal., 1984), certain cancers (Oliveria et al., 1996), and premature mortalityfrom all reasons (Blair et al.,1989, 1993, 1995). The link betweencardiorespiratory endurance and also health in youth is disputed later on in thechapter.
CARDIORESPIRATORY ENDURANCE TESTS
The gold conventional measure of cardiorespiratory endurance is maximalaerobic power (VO2max)—the best rate atwhich a perchild is able to consume oxygen during continual, exhaustiveexercise. In the laboratory, VO2max is commonly measured while aperson perdevelops maximal, graded exercise on a treadmill or cycle ergometer.VO2max can be expressed in terms of liters of oxygen consumedper minute (l/min), or the worths have the right to be normalized for distinctions in bodydimension and expressed as milliliters of oxygen consumed per kilogram of bodyweight per minute (ml/kg/min). VO2max is well-known to be a keyphysiologic determinant of cardiorespiratory endurance and also has typicallybeen offered as the criterion measure in the validation of area steps ofcardiorespiratory endurance. Many type of area measures of this fitness componenthave actually been studied and supplied in various fitness test batteries roughly thecivilization (view Table 2-6 in Chapter 2).
The most commonly used field tests involve distance/timedruns of differing length and graded-pace shuttleruns. Various kinds of distance/timed runs have been used tomeasure cardiorespiratory endurance in fitness test batteries since thedevelopment of massive fitness testing in the post–World War II era.The tests vary in framework, some being based upon a distance limitation inwhich performance is measured as time required to complete the specifieddistance (often 1 or 1.5 miles), and also others on a time limitation in whichperformance is measured as the distance extended in the mentioned time (often9 or 12 minutes). While runs as short as 600 yards were offered in earlyversions of fitness test batteries, distance runs making use of the 1 mile or9-minute format have been a lot of common considering that the 1970s.
Shuttle runs meacertain cardiorespiratory endurance once an individual runs toand from 2 different points, typically roughly 20 meters acomponent, at a setpace. The progressive aerobic cardiovascular endurance run (PACER), avariation on the shuttle run, is a maximal cardiorespiratory endurance testin which lines are placed 15 or 20 meters apart, and the participant runsrepetitively between the 2 lines within prescribed times. The time decreasesperiodically while the distance stays the exact same till the participantcannot run rapid sufficient to reach the finish line in the prescribed time.
Additionally, some fitness surveys use quasi-laboratory tests (i.e., thosethat measure VO2max yet have the right to be conducted in the field). Thesetests involve the performance of graded, submaximal exercise on atreadmill or cycle ergometer.
Literature Resee Process
As provided, the evidence for the committee"s referrals forfitness tests for cardiorespiratory endurance was acquired largely from anconsiderable evaluation of the literary works offered by the CDC, which selectedstudies measuring the associations between assorted components of fitnessand health and wellness. The CDC search strategy and also information extraction measures aredescribed in information in Chapter3. For cardiorespiratory endurance, the CDC screened 4,795studies; of these, just 260 longitudinal, speculative, andquasi-speculative research studies satisfied the CDC"s search criteriafor additionally consideration. Of this subset, the committee reviewed 47experimental research studies, 24 longitudinal prospective research studies, and also 29quasi-speculative studies. In addition to this testimonial, the committeetaken into consideration the integrity and the feasibility of the tests in a stepwiseprocedure, additionally defined in Chapter3. This area describes the committee"s evaluationof the partnership between particular tests of cardiorespiratoryendurance and health; the subsequent sections resolve the integrity andfeasibility of the tests.
The committee schosen only researches of high quality for testimonial (see Chapter 3 for a list ofgeneral selection criteria). Studies for comprehensive review were limited tothose via deindicators correct to the committee"s function, thatis, just speculative, longitudinal, and quasi-speculative research studies.(Cross-sectional researches or speculative research studies via no regulate wereexcluded.) An additional literature search (making use of search termsequivalent to those of the CDC review) was undertaken to cover studiespublished in 2011. The collection of researches was even more narrowed on the basisof the adhering to criteria. First, the examine provided vital evidencelinking a particular candiday measure of cardiorespiratoryendurance—distance/timed run, shuttle run, treadmill, cycleergometer—to a positive wellness outcome, marker, or danger aspect in4 categories (adiposity, metabolic hazard, cognitive, and other).Studies likewise were categorized as presenting direct or associationalproof. A research was characterized as presenting direct evidence once aadjust in a fitness meacertain brought about a positive change in a healthhazard aspect or outcome, and once the examine supplied proper controls andstatistical techniques to analyze the independent impact of thetreatment and also potential confounders. When making its recommendations,the committee additionally considered associational proof (i.e., from studiesthat did not take into consideration all feasible confounders) as it might constitutesupporting evidence. In basic, studies were excluded based upon theadhering to criteria: bad examine style (e.g., no control population),inappropriate populace (e.g., obese kids through complicated healthissues), lack of power to detect transforms (e.g., small sample size),inability to assess the independent effect of a dietary treatment orother vital well-known confounder, or inadequate readjust in the fitnessmeacertain of interest.
The following sections review the stamina of the evidence for apartnership in between health outcomes and the 4 categories of fitnesstests for cardiorespiratory endurance (distance/timed run, shuttle run,treadmill, and cycle ergometer). The discussion is organized by testbereason, in comparison via steps for various other fitness components (i.e.,musculoskeletal fitness and also flexibility), the committee found sufficientproof linking particular cardiorespiratory endurance tests to healthmarkers, especially cardiometabolic danger factors and also body composition.The strength of the proof is categorized as sufficient orinsufficient based on the number of research studies linking a meacertain to aspecific category of health and wellness markers, the research designs (evidence fromspeculative and longitudinal studies having actually more weight than that fromquasi-speculative studies), and also the statistical meaning of theassociation. The selected longitudinal, speculative, andquasi-speculative studies are summarized in Tables 5-1, 5-2, and also 5-3, respectively. For each study, the tables incorporate (1)the fitness test(s) supplied, (2) the health and wellness outcomes/markers examined, (3)the size and attributes of the sample, and also (4) a review of theoutcomes and the top quality and also level of the evidence.
Distance/Timed Run Tests
The committee figured out 2 speculative, one longitudinal, and also onequasi-experimental high quality studies that used assorted distance ortimed runs to meacertain cardiorespiratory endurance and itsassociation with wellness threat components. There were fewer studies inthis category of fitness tests than in the various other categories. Theranges and also times differed, and also the tests were mostly schoolbased (Chang et al.,2008; Mota et al.,2009; Sidiropoulouet al., 2007).
The researches reviewed likewise varied in their purposes, and none weredesigned especially to answer the concerns the committee wastasked to address. One high-top quality experimental research examined theassociations between an treatment and a change in fitness (asmeasured by the mentioned distance run), adiposity, orcardiometabolic hazard components (Chang et al., 2008). The authors implementedschool-based interventions and also uncovered increases in physical fitness,in addition to decreases in adiposity and renovations incardiometabolic hazard factors. This study did not examine in moredepth whether the improvements in cardiometabolic danger factors wereindependently connected with renovations in fitness and/oradiposity.
One longitudinal study discovered associations in between baseline fitnessand also gain in body mass index (BMI) over time, but did not find anassociation in between transforms in fitness and also changes in BMI over time(Mota et al.,2009). Other research studies included just a distinct population(Sidiropopulou et al., 2007).
Distance run protocols were provided in kids aged 7 and also older,although the majority of studies were of youth aged 10 and also older.The affect of gender on the relationship in between fitness andhealth and wellness danger factors was not figured out. Only one research specificallyexamined obese kids (Chang et al., 2008). Although running is aweight-bearing task, these research studies did not adjust for BMI, whichfrequently was the major health outcome of interemainder (Chang et al., 2008;Mota et al.,2009).
As with the other categories of tests questioned below, these studiesin its entirety found that outcomes of distance/timed run tests supplied tomeasure fitness in youth synchronized to wellness risk components,especially body fatness and cardiometabolic threat, in youth.
Shuttle Run Tests
The committee established 3 experimental, six longitudinal, andone quasi-experimental researches that supplied miscellaneous shuttle run testingprotocols to measure cardiorespiratory endurance and also healthoutcomes. The protocols contained the 6-minute, 20-meter shuttle runand also miscellaneous 20-meter multiphase incremental tests. The majority ofassociations were uncovered via adiposity (as measured by BMI), perhapsbecause many kind of of the studies took area in a institution setting, wright here itmight be challenging to take even more invasive measures of health riskcomponents, such as blood lipids (Aires et al., 2010; Chen et al., 2007; Kim et al., 2005; Martins et al.,2009).
One high-high quality experimental examine proved enhancements incardiorespiratory endurance in schools randomized to a comprehensivephysical activity treatment (Reed et al., 2008). These students alsoshowed improvements in blood pressure; yet, tbelow were nodetectable changes in BMI. Blood cardiometabolic hazard factors alsowere measured in a smaller subset of youngsters, but transforms in theserisk determinants were not considerable. Similarly, Murphy and colleagues (2006) discovered thatimprovements in cardiorespiratory endurance coincided toenhancements in bone ultrasound outcomes independent of any changesin BMI after a 6-month physical task intervention.
Longitudinal researches by Martins and colleagues (2009) and also Kim and colleagues (2005) demonstratedan inverse partnership in between baseline cardiorespiratory enduranceand raising BMI and incidence of overweight over 1 year and 5years, respectively. A few research studies additionally uncovered that improvedperformance on the shuttle run caused renovations incardiometabolic threat determinants (full cholesterol, low-densitylipoprotein
The shuttle run often is supplied as a meacertain of cardiorespiratoryendurance in the institution establishing bereason it requires no specialdevices, and also training the administrators of the test is relativelystraightforward. As the shuttle run is generally institution based, researches of thisform of test examined kids aged 4-17. Many kind of research studies examinedresults by gender, however only Martins and colleagues (2009) particularly state thatgender did not influence the relationship between fitness and also BMI.Puberty was self-assessed in two researches (Martins et al., 2009; Puder et al., 2011),just one of which controlled for this variable (Puder et al., 2011) (an ommision that isunderstandable offered that collecting data on pubertal status may bedifficult in a school-based setting, wbelow the majority ofshuttle run trial and error takes place). Most of these research studies also wereinclusive of all weight categories and races/ethnic backgrounds and did notspecifically study the potential influence of these factors on thepartnership in between fitness and also health hazard.
Two top quality speculative trials demonstrated renovations in fitnessand also matching renovations in bone health (Murphy et al., 2006) and also blood pressure(Reed et al.,2008). Several top quality researches also examined the longitudinalpartnership between fitness as measured by the shuttle run andalters in adiposity in schoolkids over time. Overall, thestrongest established relationships between cardiorespiratoryendurance as assessed by the shuttle run and health markers werewith adiposity as measured by BMI.
The committee established 6 speculative, 4 longitudinal, and also onequasi-speculative quality studies that supplied various treadmillprotocols (both maximal and also submaximal) to measure VO2maxand also linked health and wellness risk factors. Longitudinal studiesdemonstrated a strong attach between transforms in cardiorespiratoryendurance as measured by treadmill testing and changes in adipositymeasures such as BMI, waist circumference, and adiposity (asmeasured by skinfold and dual-power X-ray absorptiometry
A toughness of the longitudinal researches examined is that fitnesslevels in adolescence are pertained to body composition and also totalcholesterol levels in young adulthood (Eisenmann et al., 2005; Twisk et al., 2000).Twisk and also colleagues(2000) confirmed that a boost in VO2max overthis duration was positively associated with a healthy and balanced cardiovascularhazard profile in adulthood. Controlling for body fatness, the authorsdemonstrated that fitness had an independent effect on the proportion oftotal cholesterol to HDL. Another longitudinal study spanningadolescence to adulthood (mean era 26) found that time to reachexhaustion on the treadmill in teens and also the adjust in thistime competent from adolescence into adulthood were correlatedwith both adult body fatness and alters in body fatness fromadolescence to adulthood, respectively (Eisenmann et al., 2005). However before, thisstudy did not show this positive partnership via adult riskfactors for cardiovascular illness and may have been restricted by itsfairly tiny sample size (N = 48) (Eisenmann et al., 2005). Otherlongitudinal research studies used simply baseline VO2max inrelationship to alters in adiposity (Byrd-Williams et al., 2008; Johnchild et al., 2000)without examining the change in VO2max over this period.Still, these researches highlight the vital connection betweencardiorespiratory endurance and body fatness at a later time.
Experipsychological studies performed in schools and also laboratories alsodemonstrated positive relationships between changes incardiorespiratory endurance and adiposity procedures, as well ascardiometabolic risk, blood pressure, and also executive functioning(Barbeau et al.,2002; Carrel etal., 2005; Davicollection al., 1985; Farpour-Lambert et al., 2009; Gately et al., 2005). Several studiesused well-regulated maximal treadmill test protocols (Farpour-Lambert et al.,2009; Walther etal., 2009), while others used submaximal protocolsthat affiliated usage of a metabolic cart for measurement of gasexreadjust (Barbeau et al.,2002; Carrel etal., 2005; Davicollection al., 1985).
Cardiorespiratory endurance and body fatness are extremely interconnected,and also both are determinants in the danger for cardiovascular disease.Therefore, when studying associations of alters incardiorespiratory endurance with body fatness and also cardiometabolicdanger factors, it is challenging to recognize the independent causesand results. Few of the well-controlled research studies using the treadmillexamined these effects independently (Twisk et al., 2000). After a 1-yearschool-based randomized physical activity intervention, Walther and colleagues(2009) demonstrated a rise in VO2max andendothelial progenitor cells in youth without a correspondingdecrease in adiposity. Even though fat mass has an inverserelationship to weight-bearing cardiorespiratory endurance measures,numerous research studies did specifically study overweight and obese youthutilizing a treadmill protocol and also observed measurable changes incardiorespiratory endurance (Barbeau et al., 2002; Byrd-Williams et al., 2008; Carrel et al., 2005;Davis et al.,1985; Farpour-Lambertet al., 2009).
Some studies also readjusted for maturation phase (Byrd-Williams et al.,2008; Johnchild etal., 2000), and some examined the interaction betweenspecific ethnicities and also the partnership of fitness to healthmarkers (Byrd-Williams etal., 2008; Johnsonet al., 2000). Although Johnson and colleagues did notdiscover an result of ethnicity, an interactivity between sex and also theconnection of baseline fitness to transforms in adiposity wasobserved in Hispanic boys, however not Hispanic girls (Byrd-Williams et al.,2008).
Overall, the studies reviewed suggest that, among the wellness markersmeasured, adiposity and also cardiometabolic danger determinants present thestrongest evidence for an association via treadmill-measuredcardiorespiratory endurance.
Cycle Ergomeattempt Tests
The committee determined 4 speculative, three longitudinal, and3 quasi-speculative quality research studies that used assorted cycleergomeattempt tests to measure cardiorespiratory endurance and healthoutcomes. The protocols in these researches differed commonly, via themajority using maximal exercise tests. Amongst those research studies,a number of, both longitudinal and also experimental, were of high quality(Ben Ounis et al.,2010; Janz et al.,2002; Kelly etal., 2004; Ortegaet al., 2011). The weight of the proof for anassociation in between cardiorespiratory endurance as measured by cycleergometry and health danger factors was specifically solid forsteps of adiposity (BMI, waist circumference, percent body fat,fat mass), cardiometabolic danger determinants (including totalcholesterol, HDL, LDL, triglycerides, insulin resistance, glucose,and also vascular stiffness), and blood press (Ben Ounis et al., 2010; Dunton et al., 2007;Janz et al., 2002;Kelly et al.,2004; Lee et al.,2010; McMurray etal., 2008; Ortega, et al., 2011; Stella et al., 2005).
The strongest proof for a partnership between cycle ergometrytest outcomes and health and wellness danger determinants is discovered through procedures ofadiposity and also cardiometabolic danger. The toughness of the evidence incycle ergomeattempt researches appears to be comparable to that in thetreadmill research studies disputed above. Cycle ergometry researches includenumerous well-executed speculative research studies (Ben Ounis et al., 2010; Kelly et al., 2004;Wong et al., 2008)and also two longitudinal research studies that emerged over a period of 4-6years (Janz et al.,2002; Ortega etal., 2011). Kellyand also colleagues (2004) uncovered enhancements incardiorespiratory endurance, HDL cholesterol, and also endothelialfeature adhering to exercise training in overweight youth withouttransforms in adiposity, demonstrating the independent impacts ofalters in fitness on these cardiovascular illness markers (Kelly et al., 2004).Others uncovered positive results of exercise and also enhancements incardiorespiratory endurance on cardiovascular threat markers andadiposity, but were unable to identify whether these wereindependent results (BenOunis et al., 2010; Wong et al., 2008).
In longitudinal studies, cardiorespiratory endurance improvementsover 6 years from childhood to adolescence were linked with alower danger of ending up being overweight/obese in the time of adolescence (Ortega et al., 2011).Adjustment was produced constarting by baseline BMI, and also nointeractions by gender were figured out. Similarly, Janz and also colleagues(2002) demonstrated the partnership in between alters incardiorespiratory endurance over 5 years and also health markers at the5-year allude. The authors demonstrated a connection betweenchanges in cardiorespiratory endurance and proportion of totalcholesterol to HDL, LDL, and also adiposity steps.
Jekal and colleagues (2009) designed their quasi-speculative studyto evaluate the impact of a 12-week exercise regimen (Jekal et al., 2009).Although the research did not encompass a control team, measurementsbefore and after the intervention in this small research demonstrated asubstantial association of cardiorespiratory endurance through fatnessand threat factors for cardiovascular condition. Another study examinedthe impact of 12 weeks of aerobic training on plasma visfatin andinsulin resistance in normal-weight and also obese female adolescents;unfortunately, analyses were not carried out to eluciday whether thedevelopment in these danger factors was because of weight loss orrenovations in fitness or both (Lee et al., 2010). The outcomes suggestthat the interactivity between weight and cardiorespiratory enduranceis necessary, also though the authors did not analyze theindependent contributions of each of these variables to insulinresistance.
Two researches established various other wellness hazard factors—depressionand also positive self-concept—that were mitigated by increasedfitness (Dunton et al.,2007; Stella etal., 2005). Of interest is the truth that the populationof Dunton and colleagues(2007) had assorted ethnic groups, even though therewas no analysis of ethnic beginning as a potential modifier of thepartnership in between performance on the test and also self-principle.
Just like the treadmill tests, few cycle ergometry studies evaluatedinteractions via modifiers such as age or sex. Studies utilizingcycle ergometry have concentrated mostly on children aged 10 and older,with one longitudinal study examining those aged 7-10 (McMurray et al., 2008).Given the non-weight-bearing nature of cycle ergometry tests, bodyweight is not a modifying variable for these tests; a number of cycleergometry tests were conducted via overweight/obese youngsters (Ben Ounis et al., 2010;Kelly et al.,2004; Lee et al.,2010; Stella etal., 2005).
In amount, the strength of the evidence from the use of cycle ergometryto meacertain cardiorespiratory endurance and linked health and wellness riskcomponents lies through adiposity, cardiometabolic threat determinants, and also bloodpush.
Limitations of the Scientific Literature
Amongst the 4 forms of cardiorespiratory endurance tests evaluated inthese researches, all yet the distance/timed run tests showed significantrelationships to health risk determinants, specifically adiposity measuresand also cardiometabolic threat components. The studies considered of highesttop quality for each of the tests were as follows:
The most vital limitation of various other studies reviewed was the lack ofdetailed examination of confounders, especially whether improvementsin cardiometabolic danger were separately associated via improvementsin cardiorespiratory endurance or were additionally as a result of a decrease inadiposity that is often proficient when individuals take part inphysical task. In several of the speculative studies, concurrentalters were watched in adiposity procedures, cardiometabolic threat factors,and fitness (Barbeau et al.,2002; Ben Ounis etal., 2010; Carrel etal., 2005; Farpour-Lambert et al., 2009; Wong et al., 2009). In such situations, it isdifficult to recognize the independent impacts of renovations incardiorespiratory endurance on cardiometabolic hazard components.
The committee also taken into consideration whether researches examined the impacts ofassorted modifiers (e.g., age, gender) on the partnership betweencardiorespiratory endurance and health and wellness. Many kind of of the studies reviewedwere of excellent quality but were not designed through these concerns in mind.Only a subset of the researches especially examined potential modifiersof the partnership between cardiorespiratory endurance and also wellness riskfactors. For instance, studies included potential distinctions by gender(Barbeau et al., 2002;Johnchild et al., 2000;Martins et al., 2009;Puder et al., 2011;Twisk et al., 2000),race/ethnicity (Barbeau et al.,2002; Byrd-Williams etal., 2008; Johnkid etal., 2000; Tremblayand also Lloyd, 2010), age/maturation phase (Byrd-Williams et al., 2008; Johnchild et al., 2000; Puder et al., 2011), weightcondition (Twisk et al.,2000), and training standing (Sidiropoulou et al., 2007). In the majority of instances,yet, researches included no analysis of these determinants as modifiers ofperformance or as modifiers of the result of performance on wellness.
In basic, the committee taken into consideration speculative research studies to be of highertop quality bereason, by their architecture, such studies deserve to show causesand also results in an extra straight manner than is feasible through other deindicators.Yet, it need to be detailed that many of the experimental research studies measuredwellness risk factors utilizing approaches requiring invasive (i.e., blood draws)and/or precise (e.g., body complace by DXA) approaches (Barbeau et al., 2002; Ben Ounis et al., 2010;Farpour-Lambert et al.,2009; Slaughter etal., 1988; Walther etal., 2009). Likewise, many kind of studies measured fitness withlaboratory protocols utilizing either a treadmill or cycle ergometer andthrough tiny sample sizes (BenOunis et al., 2010; Farpour-Lambert et al., 2009; Kelly et al., 2004; Nourry et al., 2005). An experimental studyutilizing precision measurements would be even more most likely to detectrelationships between transforms in fitness and also transforms in adiposity andhealth and wellness risk determinants, even with small sample sizes.
VALIDITY AND RELIABILITY OF SELECTED TEST ITEMS
As discussed over, a variety of tests have actually been provided to measurecardiorespiratory endurance in research studies linking this component of physicalfitness to indicators of wellness in youth. The the majority of prevalent tests provided inmassive surveys and youth fitness test batteries are distance/timedruns, shuttle runs to volitional fatigue, and graded-exercise heart rateextrapolation tests (treadmill or cycle ergometer). The validity andrelicapacity of these tests have actually been stupassed away generally, and also severalauthors have summarized the literature on their psychometric properties.
In reviewing this literature, the committee relied primarily on reviewposts identified via searches utilizing PubMed and also Internet of Science withthe following keywords: fitness assessment, fitness testing,validity, relicapacity, children, andteenagers. As vital, the committee reviewedoriginal research short articles figured out as over or from citations noted inevaluation posts for the 3 categories of tests for which the committeediscovered the strongest evidence for a connection to health—the shuttlerun and the treadmill and cycle ergometer (i.e., heart rateextrapolation) tests. The distance run additionally is reviewed here given that it couldbe offered as an alternate in schools and other educational settings, eventhough the literary works on this kind of test is sparser.
Shuttle Run Tests
Several permutations of graded-intensity shuttle runs to volitionaltiredness have been supplied in youth fitness test batteries. The many commonis the 20-meter shuttle run as emerged by Léger, and also it is thisversion of the shuttle run that has been examined most frequently invalidity/relicapability researches (Léger et al., 1988). Performance on the test isscored as 20-meter laps completed before the participant falls behindthe pace collection by an auditory timer, and validity has actually been examined as thecorrelation in between laps completed and also measured VO2max. InLéger"s developmental examine, the correlation in between lapscompleted and also VO2max was r = 0.71 in a team of 8- to19-year-olds (Léger etal., 1988). Borehamand also colleagues (1990) and also Liu and colleagues (1992) completed similarvalidation studies and reported validity coefficients of r = 0.87 and also r= 0.72, respectively. Clearly there is strong and constant evidencethat performance on the shuttle run in young civilization correlates highlythrough weight-family member VO2max. This test likewise has actually been shown tobe a extremely trustworthy meacertain. In a current evaluation post, Artero and also colleagues (2011)report that test-retest reliability coefficients for this test haveranged from r = 0.78 to r = 0.93. Overall, the obtainable evidencesuggests that the 20-meter shuttle run has wonderful validity andreliability as a meacertain of cardiorespiratory endurance.
Treadmill and also Cycle Ergometer (Heart Rate Extrapolation)Tests
It is well known that heart rate rises livirtually with increasingintensity of endurance exercise; maximal heart rate andVO2max tfinish to happen at the exact same exercise intensity, andtherefore power output (e.g., exercise intensity) at a standard heartrate correlates highly with power output and VO2 at maximalexercise. These relationships are the basis for tests ofcardiorespiratory endurance that involve the performance of graded,submaximal exercise through heart rate surveillance. Perhaps the best knownand the majority of extensively provided of such tests is the Physical Working Capacity-170(PWC-170) test (Wahlund,1948). This test is performed on a cycle ergometer at threesignificantly raising intensities. Performance on the test isquantified as power output at a heart rate of 170 beats per minute asestimated from the linear plot of heart rate versus power output.Similar treadmill tests based on the very same principles have actually been developed(Gutin et al., 1990;National Center for HealthStatistics, 2004). Performance on the PWC-170 test has actually beenvalidated versus VO2max as a criterion meacertain. Rowland also and also colleagues(1993) discovered moderate correlationships in between absoluteVO2max and also performance on the PWC-170 in boys and also girls(r = 0.70 and 0.71, respectively), but relationships were weaker whenVO2 was expressed loved one to body weight (r = 0.65 and0.48, respectively). Boreham andcolleagues (1990) reported a high correlation (r = 0.84)between performance on the PWC-170 and also VO2max in 48adolescent boys and also girls. Of interest, in the same study, Boreham and also colleagues(1990) found that performance on the PWC-170 and also 20-metershuttle run was extremely associated (r = 0.89). The PWC-170 is highlytrusted, via test-retest correlation coefficients varying from 0.89 to0.98 (Watkins and also Ewing,1983; Watson andOdonovan, 1976).
Distance/Timed Run Tests
The validity of distance/timed runs generally has been establimelted bystudying the correlation between a criterion measure—directlymeasured VO2max (ml/kg/min) as figured out during exhaustivetreadmill running—and also test performance (distance or time). Thereviewers of this literary works have actually consistently concluded that distanceruns of 1 mile or better show acceptable validity versusVO2max. As provided by Safrit (1990) and Freedson and also colleagues (2000), correlationsin between VO2max and also performance on distance/timed runscommonly have actually been observed in the good to high range (r = –0.63to –0.90; an adverse correlation has been viewed between time tofinish and also VO2). Also, distance/timed runs have actually been foundto be dependable based upon test-retest correlationships. In summarizing studiesresearching the relicapability of distance runs, Freedboy and also colleagues(2000, pp. S80-S81) conclude that the “relicapacity of distancerun tests has actually been mainly high via correlation coefficients rangingfrom r = 0.61 to 0.92.” An even more current evaluation of researches examiningthe 1-mile run/walk test uncovered intraclass correlation coefficientsvarying from 0.39 to 0.90 in samples of kids and also teenagers (Artero et al., 2011).
Several components need to be thought about through respect to administrativefeasibility for tests that are to be supplied as part of a national survey or inschools and various other educational settings. Although many of these factors applyto all settings (e.g., price of the equipment), others relate even more closely toschools particularly (e.g., whether the test is appropriate as part of thecollege curriculum). The last considerations are disputed in more depth inChapter 9.
The determinants to be taken into consideration concerning bureaucratic feasibility aresummarized in the checklist in Box3-2 in Chapter 3. Ingeneral, these components are concerned the test topic, the facility anddevices, the administrator of the test, and the parental fees of the testsubject. The reader is referred to other publications that expand also on thesebasic factors (Mahar and also Rowe,2008). This area focuses on determinants that are particularlyrelevant to conducting cardiorespiratory endurance tests and that use toall settings.
Of interemainder is that 7 of 11 and 8 of 11 researches reregarded by the committeethat supplied the treadmill and cycle ergometer tests, respectively, utilizedmaximal protocols. Maximal tests on either the treadmill or cycle ergometerare most likely not to be administratively feasible in bigger research studies, especiallyif they are college based. Nonethemuch less, all 3 kinds of tests for whichthe committee discovered the strongest proof for a partnership tohealth—the shuttle run, the treadmill, and also the cycleergometer—are primarily feasible, and the establishing will certainly dictate theoption among these forms. For example, if room is the significant worry in testmanagement, such as in the situation of a nationwide survey, the treadmill andcycle ergometer tests will certainly be wanted.
Facility components are of certain importance as the different tests havedifferent space and devices requirements. For instance, the shuttle runneeds the a lot of space—at leastern 20 meters for the test course; thetreadmill and cycle ergometer tests require substantially less area. On thevarious other hand also, the treadmill and also cycle ergometer tests call for complex andexpensive equipment. The various room demands may have actually an influence onprivacy for test subjects, the time forced for trial and error, and also the number ofsubjects that can be tested. Training of the test administrator in testprotocols, test management, and components to take into consideration is vital to successfulmanagement of a test and also is an additional crucial consideration. Forinstance, training for administration of the shuttle run is likely to berather less facility than that compelled for the treadmill or cycleergometer test. The cost of the equipment regularly is a major consideration indeciding which test must be used. The financial cost of the devices andof training the test administrators is fairly easy to assess. However,fitness experimentation may involve a wide variety of extra straight and also indirectprices. At some point, it is essential to recognize the loved one costs versus theloved one benefits of utilizing specific tests. No formal cost/advantage analyseshave been performed for any kind of of the available tests for cardiorespiratoryendurance.
Parental components include involves around the influence of the test on the son.This may include fears regarding adverse occasions that could happen duringexperimentation, and also problem about exactly how the outcomes and also their interpretationwill affect the boy. Paleas might be particularly interested in the healthramifications of the outcomes. These concerns are most likely equally important forall recommended cardiorespiratory endurance tests.
Adverse occasions, consisting of injury throughout trial and error and the potentialmental effects of testing, have to be thought about. Adverse events ofthe miscellaneous tests for assessment of cardiorespiratory endurance have notbeen systematically evaluated in the literature. The posts selected forthis evaluation perform not report any injuries throughout testing. One current manuscript(Ruiz et al., 2011) doesresolve the safety of the 20-meter shuttle run, finding that nocomplications occurred during the experimentation, through just one report of alower-body muscle cramp. The authors note that they have actually competent nosecurity problems in more than 10,000 youngsters they have tested.
GUIDANCE FOR INTERPRETATION OF TEST RESULTS
Chapter 3 presents a detailedconversation of the interpretation of fitness tests. Discussion ofmathematical models for estimating cut-points, percentiles, or distributioncurves is beyond the scope of this report.
Low cardiorespiratory endurance clearly is pertained to a range of negativehealth outcomes, including weight problems, elevated blood push, dyslipidemia,and cardiometabolic hazard. Tbelow is also some proof that cardiorespiratoryendurance is associated via neurocognitive function. Some research studies havesaid that the lowest 3rd of the distribution of cardiorespiratoryendurance is the group at greatest risk for cardiometabolic riskfactors/metabolic syndrome, however the connection might be more of a continuousone, making particular cut-points more difficult to determine.
The committee recommends the usage of interim cut-points based on information fromboth youth and also adult populations on the relationship in between treadmillperformance and wellness outcomes till population-based evidence in youth iseasily accessible for cardiorespiratory endurance tests. The bottom quintile of thecirculation for cardiorespiratory endurance on a maximal treadmill test isconnected with elevated morbidity and also mortality (Blair et al., 1989) in adults. When interpretingtest outcomes, therefore, interim cut-points might be obtained from lowperformers (e.g., 20th percentile) in the cardiorespiratory endurancecirculation curve to identify youth at the greatest risk of poor healthoutcomes and also rise the likelihood that an individual established as lowfit is actually low fit. This is a more conservative strategy than thattaken by Lobelo and also colleagues(2009) and also Welk andcolleagues (2011), that estimate about the 30th percentileto derive cut-points for cardiorespiratory endurance tests for youth. Thecommittee"s method is based on its check out that identifying a fitindividual as low fit (perhaps recommending an exercise intervention toa test taker that does not require it) is a more significant error than identifyingan individual that is low fit as fit. It need to be provided that this approachshould take right into account covariates such as age and also sex, which allowstandardization of the interpretation of test outcomes across individualsand also, even more important, for an individual longitudinally across different periods.To derive the proper cut-points from percentiles, fitness information based onbig populaces for the test of interemainder are necessary. If such data are notavailable, developers of cut-points should consult through statisticians toarchitecture a small examine with a representative sample of U.S. youth to collectthe crucial data.
Accurate interpretation and efficient communication of test outcomes areimportant when improved fitness is a goal of the test. As discussed in Chapter 3, an individual"sresults have the right to be presented versus the background of a continuousdistribution. The consistent background shows the concept that improvedfitness in general, even within a broader selection, is linked via a lowerhazard of negative wellness outcomes. At some point, research study have to be conductedto evaluate the affect of this approach to classification and interpretationon test subjects, paleas, test administrators, teachers, medical professionals, andothers and also on future health habits.
Tbelow is a popular association in between the fitness componentcardiorespiratory endurance and health outcomes in adults. The measurementof cardiorespiratory endurance and also its partnership to wellness outcomes inyouth is fairly brand-new to the literary works. The committee"s reviewrevealed that adequate relationships have actually been establimelted betweencardiorespiratory endurance and several health and wellness risk factors in youth,including adiposity and cardiometabolic threat factors (blood press, bloodlipids and also glucose, and also insulin sensitivity). A few studies have establisheda connection with other, less-studied pediatric health and wellness hazard components, suchas actually pulmonary function, depression and positive self-concept, and bonewellness.
The literature testimonial gave to the committee had 34 articlesindicating a positive connection in between results of cardiorespiratoryendurance tests in youth and also health risk determinants, independent of otherinterventions. The evaluation contained longitudinal, experimental, andquasi-experimental researches. Tright here was extensive varicapability in the testsprovided, specifically through the protocols for distance/timed runs and also cycleergomeattempt. The features of the topics (e.g., age, sex, weight)differed also.
The cardiorespiratory endurance tests most frequently associated through a positivereadjust in a wellness threat factor were the shuttle run, treadmill, and cycleergometer tests. The health markers a lot of generally assessed were associated tobody weight or adiposity and cardiometabolic danger factors. The shuttle run,treadmill, and also cycle ergometer tests all showed strong relationships tohealth and wellness markers. Due to the fact that of the paucity of studies addressing the influenceof numerous potential modifiers of performance—age, gender,race/ethnicity, body composition, maturation status—on the variouscardiorespiratory endurance tests, the committee was unable to examine thisconcern. Such influences have actually, however, been argued in the previous (Beets and Pitetti, 2004; Bovet et al., 2007; Chomitz et al., 2010; Cureton et al., 1997; Huang and also Malina, 2007, 2010; Mahon and Vaccaro, 1989; Pate et al., 2006; Trowbridge et al., 1997).
The treadmill and also cycle ergometer tests are quasi-laboratory tests that probably ideal suited to cases where area is a limitation. Field-basedcardiorespiratory endurance tests incorporate both distance/timed runs and also theshuttle run. The shuttle run is beneficial once tright here are time constraintsand the purchase of innovative devices and also use of expert testers maynot be feasible.
The available proof indicates that all of the approaches to measuringcardiorespiratory endurance examined in this chapter demonstrate acceptablevalidity and also relicapacity. The validity and also relicapability coefficients for runsof differing ranges and also time boundaries are more variable and much less consistentlyhigh than those reported for the shuttle run and also heart rate extrapolationtests (treadmill and also cycle ergometer).
Based on its relationship to health and wellness, and its reliability, validity,and also feasibility, a timed or gradual shuttle run, such as the 20-metershuttle run, is appropriate for measuring cardiorespiratory endurance inyouth. If the test is to be administered in a setup wright here tright here are spacelimitations, a submaximal treadmill or cycle ergometer test need to be offered,even though several research studies reperceived right here were carried out with maximal tests.Submaximal protocols are recommfinished for feasibility reasons: maximal testsare not suitable for big samples or school settings because they requirethat participants satisfy particular criteria, such as reaching a certain numberof beats/minute, respiratory quotient, and oxygen intake. Furthermore,there is a prcooktop partnership between performance on a submaximal test andperformance on a maximal test. Although the proof for a relationship towellness is not enough at this time for distance/timed runs, this test isvalid and also trustworthy and could be an different in institutions and also othereducational settings.
Until population-based evidence in youth is obtainable, the lowest 20thpercentile of the distribution of cardiorespiratory endurance need to be usedto derive interim cut-points for determining whether individuals are at riskof cardiovascular-associated negative wellness outcomes. Thecommittee"s full references on cardiovascular endurance testsfor use in nationwide youth fitness surveys and in schools and othereducational settings are presented in Chapters 8 and 9,respectively.
Dunton GF, Schneider M, Cooper DM. An examination of psychosocial factors related tochanges in physical task and also fitness among femaleadolescents. Psychology & Health. 2007;22(8):929–944.
Freedchild PS, Cureton KJ, Heath GW. Status of field-based fitness experimentation in youngsters andyouth. Preventive Medicine. 2000;31(2):S77–S85.
Mahar MT, Rowe DA. Practical guidelines for valid and also trustworthy youth fitnesstesting. Measurement in Physical Education and also Exercise Science. 2008;12:126–145.
National Center for Health Statistics. National Health and Nutrition Examination Survey (NHANES)cardiovascular fitness steps manual. Washington, DC: Centers for Disease Control andPrevention; 2004.
Safrit MJ. The validity and relicapability of fitness tests forchildren: A evaluation. Pediatric Exercise Science. 1990;2:9–28.
Saltin B. In Limiting components of physical performance. Keul J, editor. Stuttgart, Germany: Thieme Publishers; 1973. pp. 235–252. (Oxygen transfer by the circulatory system throughout exercise inman).
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Tremblay M, Lloyd M. Physical proficiency measurement: The missingpiece. Physical and Health Education Journal. 2010;76(1):26–30.
Wahlund H. Determicountry of physical functioning capacity: Physiologicaland also clinical-examine via unique referral to standardization ofcardiopulmonary, useful tests. Acta Medica Scandinavica. 1948;132(Suppl. 215)