CROSSFIT-BASEDHIGH-INTENSITYPOWERTRAININGIMPROVESMAXIMALAEROBICFITNESSANDBODYCOMPOSITIONMICHAELM.SMITH,ALLANJ.SOMMER,BROOKEE.STARKOFF, ANDSTEVENT.DEVORHealth and Exercise Science, The Ohio State University, Columbus, OhioABSTRACTSmith, MM, Sommer, AJ, Starkoff, BE, andDevor, ST. Crosst-based high-intensity power training improves maximal aerobictness andbody composition. J StrengthCondRes 27(11):31593172, 2013Thepurposeof thisstudywastoexaminethe effects of a crosst-based high-intensity power training (HIPT)programonaerobictnessandbodycomposition. Healthysub-jects of both genders (23 men, 20 women) spanning all levels ofaerobictnessandbodycompositioncompleted10weeksofHIPT consisting of lifts such as the squat, deadlift, clean, snatch,and overhead press performed as quickly as possible. Additionally,this crosst-based HIPT programincluded skill work for theimprovement of traditional Olympicliftsandselectedgymnasticexercises. Body fat percentage was estimated using whole-bodyplethysmography, andmaximal aerobiccapacity (V_ O2max) wasmeasuredbyanalyzingexpiredgassesduringaBruceprotocolmaximal gradedtreadmill test. Thesevariablesweremeasuredagainafter 10weeksof trainingandcomparedfor signicantchangesusingapairedt-test. Resultsshowedsignicant (p,0.05) improvements of V_ O2max in men (43.10 6 1.40 to 48.96 61.42ml$kg21$min21) andwomen(35.9861.60to40.2261.62ml$kg21$min21) and decreased body fat percentage inmen(22.261.3to18.061.3) andwomen(26.662.0to23.2 62.0). These improvements were signicant across all levelsof initial tness. Signicant correlations between absolute oxygenconsumption and oxygen consumption relative to body weight wasfound in both men (r = 0.83, p , 0.001) and women (r = 0.94, p,0.001), indicating that HIPT improved V_ O2max scaled to bodyweight independent of changestobodycomposition. Our datashow that HIPT signicantly improves V_ O2max and body compo-sition in subjects of both genders across all levels of tness.KEY WORDS interval training, aerobic tness, bodycomposition, crosst, power trainingINTRODUCTIONHigh-intensityinterval training(HIIT) hasbeenusedasanalternativetotraditional endurancetraining for the improvement of aerobic tness.HIITis practical for many individuals due to theminimal time commitment required when compared to tra-ditional continuous endurance training. A relatively new var-iation of HIIT has recently become popular and incorporateshigh-intensity resistance training using varied, multiple-jointmovements. This high-intensity power training (HIPT) mayalso offer improvement of aerobic tness with minimal timecommitment compared with traditional aerobic training.HIPThas recentlybecome popular worldwide; however,proponentshavemademanyunsubstantiatedclaims.HIPTdiffers fromtraditional HIITinthat it includesalackofaprescribedrestperiod, focusonsustainedhighpower output anduseof multiplejoint movements. Thiscrosst-based, HIPTprogram uses named workouts of theday (WOD) invariedtimedomains. HIPTincorporatesfunctional lifts such as the squat, deadlift, clean, snatch, andoverheadpress. Additionally, HIPT commonlyusesbasicgymnasticexercisesusingrings, hand-stands, andparallelbars. Someworkouts areperformedfor abest time, andothersareperformedintheasmanyroundsaspossible(AMRAP)styleusingvaryingtimedomains, rangingfrom10 to 20 minutes. For example, a popular WOD uses 3 setsof21, 15, and9repetitionsof barbell frontsquatswithanoverhead press, immediately followed by body weightpull-ups. ThisWODisperformedwiththegoal of com-pletingtheexercises as quicklyas possible. Insummary,aHIPT trainingsession willoftenincludearandomselec-tionof multiple joint exercises andtrainparticipants tocompletethesemovements at highresistanceas quicklyas possible. Thesustainedhighpower output associatedwithHIPTmight serveasastimulusforpositiveadapta-tions of maximal aerobic capacity (V_ O2max) and bodycomposition.Although HIIT has been shown to improve bodycomposition(13) andV_ O2max(14) inhealthyadults, it isnotclearif HIPT couldofferthesesamebenets. Todate,therehavebeennopublishedinvestigations documentingchanges to V_ O2max or body composition in response to thisAddress correspondence toDr. Steven T. Devor, devor.3@osu.edu.27(11)/31593172Journal of Strength and Conditioning Research 2013 National Strength and Conditioning AssociationVOLUME 27 | NUMBER11| NOVEMBER2013 | 3159Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.styleoftraining. Therefore, ouraimwastodetermineifanHIPT training regimen could yield signicant improvementsto V_ O2max and body composition in healthy adults. Toachieve our aim, we measuredmaximal aerobic capacityusingaBruceprotocolgradedexercisetestandbodycom-position with whole-body plethysmography in healthy adultvolunteersbeforeandafteracommonHIPTtrainingpro-gram. Wetestedthehypothesisthata10-weekHIPT regi-men would improve V_ O2max and body composition inhealthy adult volunteers. Furthermore, we hypothesized thatimprovementsofV_ O2maxandbodycompositionwouldbefoundacross all levels of initial aerobic tness andbodyFigure 1. Representativesample of high-intensity power training protocol. AMRAP = as many rounds as possible; double-unders = 2 jump rope passes perjump;HS=hand stand;HSPU= handstandpush-up;HSW=handstand walk;KB =kettlebell.Percentageslistedas relative toparticipants1-repetitionmaximum.CrosstTrainingImprovesAerobicFitnessandBodyComposition3160 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.TABLE1. CompleteWOD list for 10weeksof HIPT training.*Date Strength/skill WOD NotesWeek11/9/2012 Back squat,3 3 5 Forbest time: 95lbsFormen,65lbs for women forthrusters5@65% 1RM 50Air squat 15:00Timelimit5@75% 1RM 3 Flightstairs5@85% 1RM 100 Double underjump rope25 BurpeesAssistpull-up 50Double underjump rope5@65% 1RM 25 Burpees5@75% 1RM 100 Double underjump rope5@85% 1RM 3 Flightstairs50Air squat1/10/2012 10-mindoubleunders AMRAP 12min: HS;for novices10-minHSW/HSPU/HS 7 Pull-ups HSPU; forintermediates1-mile Runfor best time 14 Frontsquat HSW; for advanced21 Push-upswithrelease1/11/2012 Deadlift Forbest time: As many3RM aspossible in20 min5@65% 1RM 30Clean andjerk 135 lbsFormale,95 lbsfemale5@75% 1RM5@85% 1RM1/12/2012 Ringwork 10min 21Kettle bell swings 70-lbKettlebell formen,53-lb kettlebell for womenPull-ups anddips 21Ringdips15 Kettlebell swing15Ringdips9 Kettlebell swings9Ringdips1/13/2012 Backsquat 3Rounds for time:5@65% 1RM 5Wide gripdeadlift/highpull 135 lbsFormen,95 lbswomen5@75% 1RM 5 Squat press5@85% 1RM 5 Pull-upsAssistpull-ups5@65% 1RM5@75% 1RM5@85% 1RMWeek21/16/2012 Thrusters5 @85%1RM Franfor best time:21Thrusters21Pull-ups15Thrusters15Pull-ups9Thrusters1/17/2012 10-minHSW/HSPU/HS AMRAP 12min: HS for novices,HSPU forintermediate,HSW foradvanced7 Pull-ups14Front squats 95lbsFormen,65lbs for women forsquatsJournal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3161Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.21Push-ups withrelease1/18/2012 Deadlift,3 3 5 30Highhangpower cleanand jerks135 lbsFormen,95 lbs for women5 @65% 1RM5 @75% 1RM5 @85% 1RMOverheadpress, 33 55 @65% 1RM5 @75% 1RM5 @85% 1RM1/19/2012 10-minMuscleup practice Angiein reverse,for time: 20-minMaxtimelimit10-minPistol squatpractice 100 Body weight airsquats100 Sit-ups100 Push-ups100 Pull-ups1/20/2012 Backsquat,3 3 5 3Rounds,1-min restbetweenrounds:5 @65% 1RM 5 RepsSumodeadlift highpull 135 lbsFormale,95lbsfor female5 @75% 1RM 5 Repsthruster 135 lbsFormale,95lbsfor female5 @85% 1RM 5 Pull-upsWeightedpull-up5 @65% 1RM5 @75% 1RM5 @85% 1RMWeek3Deadlift, 3sets 3 3 reps AMRAP, 20min1/23/2012 3 @70% 1RM 10Highhangpowercleans 60% of1RM forpowercleans3 @80% 1RM 10Toeto bar3 @90% 1RM 10BurpeesOverhead press,3 sets3 3reps3 @70% 1RM3 @80% 1RM3 @90% 1RM1/24/2012 Advanced:muscleups 3 Roundsfor time:4 Setsof1RM 400-mRun15Pull-upsBeginner:ringpush-ups 30Sidelungesw/dowel overhead4 Setsof1RM1/25/2012 Back squat,3sets 3 3 reps3 @70% 1RM3 @80% 1RM3 @90% 1RMPull-ups 3 Roundsfor time:5 @70% 1RM 20 Backsquats 135 lbsFormen,95 lbs for women3 @80% 1RM 6 Flightsofstairs3 @90% 1RM1/26/2012 10-minPracticesnatch form 21Reps highhangpowersnatch 95lbsFor men,65lbsfor women10-minHSW/HSPU/HS 21 Repswall ball 10 Distancefromwall,20 lbsformen,14lbsforwomen15Reps highhangpowersnatch15 Repswall ball9 Repshighhangpowersnatch9 Repswall ball1/27/2012 Hangpower clean,3 sets3 3 reps 30Double undersCrosstTrainingImprovesAerobicFitnessandBodyComposition3162 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.3@70% 1RM 21Deadlift 185 lbsFormen,115 lbs forwomen3@80% 1RM 21Box jumps 24 Formen,20for women3@90% 1RM 30 Doubleunders15DeadliftsPushpress,3 sets 15Box jumps5@70% 1RM 30 Doubleunders3@80% 1RM 9Deadlifts3@90% 1RM 9Box jumpsWeek41/30/2012 3 Setsback squat Every30s until fatigue: 185 lbsFormen,115 lbs forwomen5@75% 1RM 1Power clean3@85% 1RM 1 Highhangpowerclean1@95% 1RM 1Push jerkPull-ups5@75% 1RM3@85% 1RM1@95% 1RM1/31/2012 Rest Fortime: Fornovice:substitute burpeefor double unders50 Doubleunders50 Sit-ups40 Doubleunders40 Sit-ups30 Doubleunders30 Sit-ups20 Doubleunders20 Sit-ups10 Doubleunders10 Sit-ups20 Doubleunders20 Sit-ups30 Doubleunders30 Sit-ups40 Doubleunders40 Sit-ups50 Doubleunders50 Sit-ups2/1/2012 3Setsdeadlift 5 Roundsfor best time: 155 lbsFormen,95 lbs for women5@75% 1RM 12Deadlifts3@85% 1RM 9 Highhangpowerclean1@95% 1RM 6Push jerk3 Setsoverhead press5@75% 1RM3@85% 1RM1@95% 1RM2/2/2012 Gymnasticsringwork: 1Round fortime: Ringwork doneforformand attheskill level ofeachindividualToesto rings 1,000-mRunLeverhang 50Kettle bell swings 53-lbKettlebellfor women,35-lbKettlebellfor menJournal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3163Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.Leverpull-up 100 Bodyweight squatsMuscleupDipLeversitForward rollBack lever2/3/2012 3 Setsfront squat Forbest time:5 @75% 1RM 10Repsfront squat 135 lbs Formen,95 lbs for women3 @85% 1RM 15 Ropeclimb1 @95% 1RM 9Repsfront squat15 Ropeclimb3 Setspull-up 8Repsfront squat5 @75% 1RM 15 Ropeclimb3 @85% 1RM 7Repsfront squat1 @95% 1RM 15 Ropeclimb6Repsfront squat15 Ropeclimb5Repsfront squatWeek52/6/2012 Snatchtechniquepractice10min 3 Roundsfor besttime:(noload orrep requirement) 15Reps deadlift@60% of1RM15 Kneesto elbows2/7/2012 Turkishgetuptechniquepractice 10min 2 Roundsfor besttime: Assist bandsusedfor novice(noload orrep requirement) 12Chest to barpull up 24 Box for men,20 box forwomen12 Box jumpsPull-uptechniquepractice10 min 9Chest to barpull-up(noload orrep requirement) 9 Box jumps6 Chest to barpull-ups6 Box jumps2/8/2012 Jerktechniquepractice10min Forbest time:(noload orrep requirement) 21 Squat cleans 95 lbsFormen,65lbsfor women21Push-upwithrelease15 Squat cleans15Push-upwithrelease9 Squat cleans9Push-up withrelease2/9/2012 Muscleup techniquepractice10min Forbest time: As little assistanceas possible givenduringmuscleups(noload orrep requirement) 5Muscle ups Novice men:53-lbkettlebells30Kettlebell swings Advanced men: 70-lb kettlebells4Muscle ups Novice women:35-lb kettlebells25Kettlebell swings Advance women:53-lbkettle bells3Muscle ups20Kettlebell swings2Muscle ups15Kettlebell swings1Muscle up10Kettlebell swings2/10/2012 Overheatsquat technique10min 3 Roundsfor besttime:(noload orrep requirement) 30Double undersCrosstTrainingImprovesAerobicFitnessandBodyComposition3164 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.10Overhead squats 95lbsFormen,65lbsfor women10HSPU HS/HSWfornoviceandintermediates1Flightof stairsWeek62/13/2012 3 Setsofback squats 8 Roundsfor maxreps:5 Reps@75% 1RM 20-s Deadlift1RM10-s Rest20-sHSPU HS substitutedfornovice10-s Rest2/14/2012 Rest AMRAP in 20min3 Burpees5 Pull-ups2/15/2012 3 Setspowerclean Rest5 Reps@75% 1RM2/16/2012 Rest Rest2/17/2012 3 Setsoverhead squat Rest5 Reps@75% 1RMWeek72/20/2012 5 Setsback squat AMRAP in 20min5 Reps@65% 1RM 5 Pull-ups10Body weightsquat20 Doubleunders2/21/2012 7Setsdeadlift AMRAP in 10min2 Reps@60% 1RM 4 HSPU8Deadlifts 225 lbsFormen,135 lbs forwomen16Kettle bell swings 53lb Kettlebell formen,35 lb kettlebell for women2/22/2012 7Sets benchpress 4 Roundsfor best time:3 Reps@75% 1RM 30Splitjumps10Squat press 95lbsFormen,65lbsfor women20Push-ups2/23/2012 Powerclean practice,15min 18-minAMRAP:135 lbsFormale,95lbs female 15Box jumps 24 Box for men,20 box forwomen12Overhead presses 115 lbsFormen,75 lbs for women9Toes to bar2/24/2012 3Setsfront squats 5 Roundsfor best time:5 Reps@65% 1RM 20Pull-ups3 Reps@75% 1RM 30Push-ups1 Rep@85% 1RM 40 Sit-ups50Body weightsquats30-minRestbetweenroundsWeek82/27/2012 3 Setsback squats Forbest time:5 Reps@65% 1RM 15Thrusters3 Reps@75% 1RM 15Pull-ups1 Rep@85% 1RM 12Thrusters12Pull-ups9Thrusters9 Pull-ups12ThrustersJournal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3165Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.12Pull-ups15Thrusters15Pull-ups2/28/2012 Pistol andHSPU drills: AMRAP15 min:HSW 9 Deadlifts 155 lbs for men,100 lbsforwomenParallettes 12Push-ups withreleaseDB presses 15 Box jumps 24 Box for men,20 box forwomenWall walksShoulder touches(noload orrep requirement)2/29/2012 3 Sets, 5repsbench pressfor form 5 Roundsfor time:15 Ropeclimb10 Wall ball 10 Distancefromwall,20 lbsformen,14lbsforwomen15 Toesto bar20Kettlebell swings 53 lbsFormen,35lbsfor women3/1/2012 10-minPowersnatch practice 10-minAMRAP Men/women75/45-lbSnatch,30 reps135/75-lbSnatch,30reps165/100-lb Snatch,30reps210/120-lb Snatch,as many as possible3/2/2012 3 Setsfront squat5Reps@ 65%1RM Rest3Reps@ 75%1RM1Rep@85% 1RMWeek93/5/2012 Low barback squat AMRAP20 min:5Sets, 5 reps@65% 1RM 5 Pull-ups10 Bodyweight squats20Double unders3/6/2012 HSPU practice,10min AMRAP 10minDeadlifts7 sets, 2reps@ 55%1RM 4 HSPU HS for novice(workon form) 8 Deadlifts 225 lbs Formen,135 lbswomen16Kettlebell swings 53 lbsMen,35 lbswomen3/7/2012 Bench press Not for time:7Sets, 3 reps@65% 1RM 4 Rounds30 Splitjumps10Thrusters 95 lbsMen,65 lbswomen20 Push-ups3/8/2012 Rest AMRAP18 min:15 Box jumps 24 Box for men,20 box forwomen12Push presses 115 lbs Formen,75lbswomen9 Toesto bar3/9/2012 Rest Forbest time:5 Rounds,3-minrestbetweenrounds20Pull-ups30 Push-ups40Sit-upsCrosstTrainingImprovesAerobicFitnessandBodyComposition3166 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.composition, not onlyinthecohorts of thelowest initialvaluesofthese markers.METHODSExperimentalApproach to theProblemThis study investigated the effect of a 10-week, crosst-based,HIPT program on body composition and V_ O2max in healthyadults. Body composition using air displacement plethysmog-raphyandmaximalaerobiccapacityusingaBrucetreadmillgradedexercisetest wereassessedinall thesubjectsinthemorning(7:3011:30AM)overa5-dayperiodprecedingtheonset of training. Measurements were obtained after an over-night fast, andthesubjectsrefrainedfromexercise, alcohol,and caffeine for the previous 24 hours. A total of43 subjectscompleted the training programandreturnedforassessmentofchangesinthedependentvari-ablesofbodycompositionandV_ O2max. All returningsubjectswere assessed atthe same timeof the day as the pretrainingmeasures over a 5-dayperiodafter the completion of theprogram.SubjectsThe participants of all levels ofaerobictnessandbodycom-position were recruited fromandtrainedat aCrosst afli-ate(Fit Club, Columbus, OH,50Body weightsquatsWeek103/12/2012 Lowbarback squat AMRAP 15min:3 Sets, 5reps @50% 1RM 3Reps hangclean 115 lbsFormen,75 lbs for women3 Sets, 5reps @65% 1RM 3Thrusters3 Sets, 5reps @75% 1RM 3 Ropeclimbs3 Sets, 5reps @85% 1RM3/13/2012 Benchpress3 Sets, 5reps @50% 1RM3 Sets, 5reps @65% 1RM 4 Roundsfor best time:3 Sets, 5reps @75% 1RM 5 Muscleups Assistfor novices3 Sets, 5reps @85% 1RM 30 Doubleunders10 Dips3/14/2012 15-minPowercleans 7Rounds for time:Emphasison form 10 Burpees10Clean highpulls 95lbsFormen,65lbswomen3/15/2012 Rest AMRAP 12min:150 Wall ball 10ft Fromwall, 20lbsmale, 14lbsfemale90 Doubleunders30 Muscleups Assistfor novices3/16/2012 Rest 3Rounds for time:800-mRun50Romaniandeadlifts 45lbsFormen,45lbswomen50 Sit-ups*AMRAP = as many rounds as possible; double-unders = 2 jump rope passes per jump; HS = hand stand; HSPU = hand standpush-up; HSW = hand stand walk; HIPT = high-intensity power training; KB = kettle bell; WOD = workouts of the day; RM = repetitionmaximum.TABLE2. Subjectcharacteristics.*Men(n= 23) Women(n =20) RangeAge(y) 33.9 6 1.6 31.2 6 1.3 21.048.0Height(in.) 70.6 6 0.6 64.8 6 0.6 60.077.0Weight(kg) 90.71 6 2.67 68.026 3.00 44.54118.18BMI(kg$m22) 28.1 6 0.6 25.1 6 1.1 19.137.4Bodyfat (%) 22.2 6 1.3 26.6 6 2.0 10.746.1Leanmass (kg) 70.25 6 1.76 49.006 1.10 36.3582.17V_ O2max(L$min21) 3.88 6 0.13 2.39 6 0.09 1.475.12V_ O2max(ml$kg21$min21) 43.10 6 1.40 35.986 1.60 20.0058.00*BMI =bodymassindex; in. =inches; kg=kilograms; V_ O2max=maximal oxygencon-sumption.All data are resting values and are presented as mean 6 SEM.Journal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3167Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.USA). Out of the original 54participants, a total of 43(23men, 20 women) fully com-pleted the training programand returned for follow-up test-ing. Of the 11 subjects whodropped out of the trainingprogram, 2 cited time concernswiththeremaining9subjects(16% of total recruited subjects)citing overuse or injury forfailing to complete the pro-gram andnish follow-up test-ing. The subjects hadalreadybeenfollowing a Paleolithictype of diet before and aftercompletion of the training pro-tocol. All the subjects providedwritteninformedconsent, andall studymethods andproto-cols were approved in advanceby the Institutional ReviewBoard at The Ohio StateUniversity.ProceduresTraining Program. The subjectsparticipated in a crosst-basedHIPTprogram using basic gym-nastic skills (handstands, ring,and bar exercises) and traditionalmultiple-joint, functional, resis-tance exercises (squat, press,deadlift, Olympic lifts) per-formedasquickly aspossibleatahighintensity(lowrepetition,highpercentageof 1-repetitionmaximum). All training was per-formed at a CrossFit afliateunder the supervision of a fellowof the American College ofSports Medicine (ACSM) andan ACSMcertied registeredclinical exercise physiologist.The10-weekprogramwasvar-iedsothatsomeexerciseswereperformedfor abest time, andothers were performed in theAMRAPstyle invarying timedomains ranging from10 to20 minutes. During the strengthandskillportionoftheexercisesession, there was no prescribedrecovery time, whereas duringthe WOD portion of the session,TABLE3.Adaptationsin malesubjectsafterthe10-week HIPT.*Pretraining Posttraining pWeight (kg) 90.716 2.67 87.256 2.58 0.0008BMI(kg$m22) 28.1 6 0.6 27.06 0.6 0.0006Bodyfat (%) 22.2 6 1.3 18.06 1.3 0.000002Lean mass(kg) 70.256 1.76 71.236 1.87 0.001V_ O2max(L$min21) 3.88 6 0.13 4.236 0.13 0.001V_ O2max(ml$kg21$min21) 43.106 1.40 48.966 1.42 0.000004*BMI=bodymassindex;V_ O2max=maximal oxygenconsumption;HIPT=high-intensitypower training.All data are resting values and are presented as mean 6 SEM.TABLE4.Adaptationsin femalesubjectsafter10-week HIPT.*Pretraining Posttraining pWeight (kg) 68.02 6 3.00 66.23 6 2.70 0.01BMI(kg$m22) 25.1 6 1.1 24.4 6 1.0 0.01Bodyfat (%) 26.6 6 2.0 23.2 6 2.0 0.00008Lean mass(kg) 49.00 6 1.1 50.06 6 1.2 0.01V_ O2max(L$min21) 2.39 6 0.09 2.62 6 0.1 0.005V_ O2max(ml$kg21$min21) 35.98 6 1.60 40.22 6 1.62 0.0006*BMI=bodymassindex;V_ O2max=maximal oxygenconsumption;HIPT=high-intensitypower training.All data are resting values and are presented as mean 6 SEM.Figure2. Maximal aerobic tnessandbody compositionimprovements aftera10-weekhigh-intensitypowertrainingintervention. Aftertraining,theV_ O2maxincreasedandbodyfat percentage decreasedsignicantly.*p, 0.05.CrosstTrainingImprovesAerobicFitnessandBodyComposition3168 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.thesubjectscompletedalltheexercisesasquicklyaspossiblewith no prescribed rest period. Two representative weeks of thetrainingprogramarefoundinFigure1. Thesubjects wereasked to refrain from all other structured physical activity whileparticipating in this study, and they complied with this request,as veriedbyactivitylogs. Acomplete list of all exercisesperformed over the 10 weeks is found in Table 1.BodyComposition. Percentagebodyfat wascalculatedusingtheBodPodair-displacementplethysmographydevice(LifeMeasurements Instruments,Concord, CA, USA), whichisshown to be an accuratemethod for assessing body com-position in adults (2). Beforemeasurement, the systemwascalibrated for volume usingacylinder of aknownvolume(50.1461L)andformassusingtwo 10-kg weights. Fasting-statebodyweight was measuredtothe nearest 0.1 kg, and the sub-jects entered the Bod Podchamber wearing only a tightttingswimsuit andswimcap.Body volume measurementswere taken in duplicate andrepeatedif measures were notwithin 150 ml of each other(7). Body density was calculatedas mass/body volume and bodyfat percentage was calculated byusingSirisformula(12). Bodymassindexwascalculatedaskilograms ofbody mass divided by height in meters squared.Graded Exercise Testing. All the subjects performed a maximaltreadmill exercisetest beforeandafter thetrainingprogramusingtheBruceprotocol(4)todetermineV_ O2max. Thesub-jectsworenoseclipsandbreathedintoa1-waymouthpiece,which allowed expired gases to be collected in a mixing cham-ber. The volume of expired air, oxygen consumption, and car-bon dioxide production were determined by gas analyzers anda pneumotachometer attachedto a calibrated, computerizedmetabolic cart (Parvomedics,Sandy, UT, USA), whichpro-vides accurate and reliable re-sults compared with theDouglas bagmethod(6). Oxy-gen consumption values werecalculated every 15 seconds,and the 2 highest consecutivevalues wereaveragedtodeter-mineabsolutemaximal oxygenconsumption in litersper minute. Body weight wasdivided into absolute oxygenconsumption to yield a value rel-ative to body mass and isreported as relative V_ O2maxin units of milliliters ofO2$per kilogram of bodymass$per minute. Thetest wasterminated and considered max-imal when subjects reached self-Figure 3. Changes in maximal relative aerobic tness after a 10-week high-intensity power training intervention.When brokeninto quantiles ofinitial aerobic tness scaledto bodyweight, a signicant increaseof theV_ O2maxfrombaselinewasobservedin all groups.**p ,0.01;*p , 0.05.Figure 4. Changes in maximal body composition after a 10-week high-intensity power training intervention. Whenbroken into quantiles of initial body composition, a signicant decrease from baseline was observed in all groups.**p ,0.01; *p , 0.05.Journal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3169Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.determined exhaustion, and wasveried by the 2 of following cri-teria: (a) plateau in oxygen con-sumption despite an increasein workload, (b) respiratoryexchange ratio .1.1, and (c) rat-ing ofperceivedexertionof1820. Using these parameters havepreviously shown to be a reliablemethod of verifying V_ O2max hasbeenattained, andprovidessta-tisticallyindistinguishablemeas-urements compared withsupramaximal testing(8). Meta-bolic sensors were recalibratedbetween each exercise test.StatisticalAnalysesChangesof V_ O2maxandbodycomposition frompretrainingto posttraining were testedusing a 2-tailed, pairedt-test.These values were tested asan entire group, and also in sub-setsthat werestratiedbyini-tial values of aerobic tness andbodycomposition,respectively.These subsets were based onnormativedatafortheageandgender of eachparticipant (3).Percentilerankings correspondtodescriptors as follows: wellabove average (.90), aboveaverage (7090), average (5070), below average (3050),and well belowaverage (1030). Two-tailed, paired t-testswerethenusedtotest thedif-ferences between pretrainingand posttraining values ofV_ O2max and body composi-tion. A forward stepwise multi-variate linear regression wasperformed to identify signi-cant predictors of relativeV_ O2max. The model consid-ered the following variablesfor inclusion: changeinabso-lute V_ O2max and body fat.Additionally, a linear regres-sion analysis was performed,andPearsoncorrelationcoef-cients were calculated to deter-mine the contribution ofchanges intotal bodyweight,Figure 5. Changes in absolute maximal aerobic tness after a 10-week high-intensity power training intervention.When broken into quantiles of initial absolute aerobic tness, a signicant increase of the V_ O2max from baselinewasobservedin theWell-belowavg,Below avg,and Aboveavg groups.**p , 0.01;*p ,0.05.TABLE 5. Multivariate regression analysis model forDV_ O2max (ml$kg21$min21).*Gender Variables b6 SEM p R2Male D AbsoluteV_ O2max(L$min21) 12.50 6 1.05 0.001 0.88D Bodyfat (%) 20.67 6 0.12 0.001Female D AbsoluteV_ O2max(L$min21) 13.62 6 1.06 0.001 0.91D Bodyfat (%) 20.32 6 0.19 0.100*Model wasbuilt usingchangesof absoluteV_ O2maxandbodyfat against changesinrelative V_ O2max inboth genders.TABLE6.Correlation matrixforDV_ O2max (ml$kg21$min21).*Gender VariablesDAbsV_ O2max(L$min21)DLM(kg)DBF(%)DWeight(kg)Male DV_ O2max(ml$kg21$min21)0.83 0.05 20.49z 20.24Female DV_ O2max(ml$kg21$min21)0.94 0.05 20.07 0.01*DAbsV_ O2max =changeinabsoluteV_ O2max frompretrainingtoposttrainingvalues;DV_ O2max=changeinrelativeV_ O2maxV_ O2maxfrompretrainingtoposttrainingvalues;BF=body fatpercentage; LM= lean mass.p, 0.001.zp , 0.05.CrosstTrainingImprovesAerobicFitnessandBodyComposition3170 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.lean mass, and absolute oxygen consumption to theobservedincreaseinrelativeV_ O2max. Dataarereportedasmean 6 SEM. Statistical analysis was performed using STA-TA(version11.1, CollegeStation, TX,USA). Statisticalsig-nicance was dened a priori as the critical a-level ofp#0.05.RESULTSCharacteristics of the subjects who volunteered for the studyare presented in Table 2. The mean and SEM of the variablesbeforeandaftertrainingformalesubjectsarepresentedinTable3, andfemalesubjects inTable4. After thetrainingprogram, a signicant increase in the relative V_ O2max anddecreaseinpercent bodyfat wereobserved. ThesechangesarepresentedinFigure2. Thedifferencesinrelativeoxygenconsumption and body composition were signicant when bro-kenintoquantiles of well-belowaverage, belowaverage,average, above average, and well-above average, indicatingimprovement across all initial levels of tness (Figures 3 and 4).ImprovementintheabsoluteV_ O2maxwasfoundinthewell-below average, below average, and above average groups (Fig-ure 5). A regression analysis revealed that the absolute V_ O2maxand body fat percentage were signicant predictors of thechangeintherelativeV_ O2maxinmen(p=0.001), but onlyabsolute V_ O2max was a predictor of relative V_ O2max in women(Table 5). Furthermore, the improvement of maximal relativeaerobic capacity could be explained by an increase in absoluteoxygen consumption in men (r = 0.83, p = 0.001) and women(r = 0.94, p = 0.001), and was further informed by the corre-lation of a decrease in body fat in men only (r =0.49,p = 0.05). This correlation analysis is presented in Table 6.DISCUSSIONThe aim of this research was to examine the effects of a novel,crosst-based HIPTprogramon aerobic tness and bodycomposition in healthy adults. The results presented hereconrmour hypothesisthat a10-weekcrosst-basedHIPTprogramsignicantlyimprovesthemaximalaerobiccapacityandbodycompositioninindividualsof all tnesslevelsandgenders. The improvement of the relative V_ O2max was stronglymediated by improvement of absolute oxygen consumption inwomen, and by improvement of absolute oxygen consumptionanddecreasedbodyfatinmen. AlthoughtheHIIThaspre-viouslybeenshowntoimprovebodycomposition(13) andV_ O2max(14) inhealthyadults, this is therst investigationshowingthatsimilarbenetscanbeobtainedusingacrosst-based HIPT program.AftertheHIPTtraining, bodyfatpercentagedroppedby3.7%, acrossall individuals, in absolute terms. This reductioncorresponds to a pretraining to posttraining change of 15.5%.AspresentedinFigure4, thereweresignicant declinesinbodyfatpercentageforall tnesscohorts. Thisndingalsoholds when comparing men and women. Tables 3 and 4 showtheresultsformenandwomen, respectively. Absoluteandpercentage changes in body fat were similar for both genders.Theseresultsindicateapositiverolefor HIPTinreducingbody fat percentage in both genders across all levels of initialtness. However, giventhebodycompositionchangesthathave been observed in response to a Paleolithic type diet (10),it is impossible to ascribe the entirety of the improvement inbody composition in our subjects to HIPT training alone.The results for oxygen consumption again reveal thatquantiles of all initial levels of tness were improved inresponsetoanHIPTtrainingregimen. Oxygenconsump-tion, as expressed relative to body weight, signicantlyincreased across all groups (Figure 3). Again, men andwomenattainedsimilarimprovementsinrelativeV_ O2max,13.6 and 11.8%, respectively (Tables 3 and 4). As commonlyunderstood, improvement of relative V_ O2max can result fromincreased absolute oxygen consumption, decreased bodyweight, or changes in both. Our data indicatethat improvement of absoluteoxygenconsumptionis theprimary factor in the improvement of relative V_ O2max, witha small contribution of the reduction of body fat percentageinmenonly. Toour knowledge, thisis therst report ofimprovement of relativeandabsoluteV_ O2maxinresponsetoa crosst-basedHIPT training protocol.Combiningthequantilestorepresent menandwomen,Tables 3 and 4 showa signicant increase of absoluteV_ O2max for both genders. These ndings show that aerobicbenets canbegainedthroughHIPT, regardless of initialtness or gender. Past HIITtraininghas revealedsimilarimprovements in V_ O2max. Astorino et al. reported .6%increaseinabsoluteV_ O2maxand5.5%increaseinrelativeV_ O2max, whereasTruliketal. reporteda13.4%increaseinrelative V_ O2max in response to HIIT. Our nding thatimprovement of V_ O2maxinsubjects whoarestratiedaswell aboveaverageisatoddswithpreviousworkusinganHIITprotocol that nds noimprovement of V_ O2max(5).EvenHIIT studiesinwell-trainedsubjectsusinghyperoxiahavepreviouslyfailedtondanimprovement of oxygenconsumptioninthesubjects of comparablyhighV_ O2max(9,11). ComparedwithHIIT, ourresultsindicateapossiblesuperior role for HIPT in the improvement of maximal aer-obic capacity in well-trained subjects. Future studies areneededinthis area.Auniqueconcernwithanyhigh-intensitytrainingpro-gramsuchasHIPT orothersimilarprogramsistheriskofoveruse injury. Despite a deliberate periodization andsupervision of our Crosst-based training program bycertiedtness professionals, anotablepercentageof oursubjects(16%)didnot completethetrainingprogramandreturnfor follow-uptesting. Althoughpeer-reviewedevi-dence of injuryrates pertainingtohigh-intensitytrainingprogramsissparse, thereareemergingreportsofincreasedrates of musculoskeletal and metabolic injury in theseprograms (1). This may call into question the risk-benet ratiofor such extreme training programs, as the relatively small aer-obic tness andbodycompositionimprovements observedamongindividualswhoarealreadyconsideredtobeaboveJournal of Strength and Conditioning Researchthe TM| www.nsca.comVOLUME 27 | NUMBER11| NOVEMBER2013 | 3171Copyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.average and well-above average may not be worth the riskof injuryandlost trainingtime. Furtherworkinthisareaisneeded to explore how to best realize improvements to healthwithout increasing risk above backgroundlevels associatedwith participation in any nonhigh intensity based tnessregimen.Inconclusion, wecaninferfromourdatathatacrosst-based HIPT training program can yield meaningful improve-ments of maximal aerobic capacity and body composition inmen and women ofall levels of tness. The improvementofmaximal oxygen consumption expressed as a function of bodymass was signicantly correlated to increased absolute oxygenconsumption, indicating that HIPTcan improve aerobictnessindependentofanyconcurrentweightloss. Althoughimprovements in aerobic tness are similar to those previouslyfound in HIITprograms, the current HIPTprogramhasdemonstratedanincreaseof maximal oxygenconsumption,even in subjects with well-above average V_ O2max. ThisincreaseinV_ O2maxhasnotpreviouslybeendocumentedinresponsetoanHIIT program, indicatingthatHIPT maybeapossiblestrategyfortheimprovementofaerobictnessinathletes who are considered to be well-above average. Futureresearch is needed to investigate these differences.PRACTICALAPPLICATIONSToour knowledge, noresearchontheaerobicbenetsofHIPT hasbeenconducted. HIPT focusesonhighintensityresistance training using multiple joint exercises, with little tonofocusontraditional aerobicactivities. Despitethis, ourresultsshowthatthistypeoftrainingalsoprovidesaerobicand body composition benets. The increased aerobiccapacityof thesubjectsinourHIPT studyweresimilartothose foundinpast research(5,13). Basedonthe resultspresentedhere, individuals of all tness levels andeithergender canrealizebodycompositionandaerobicbenetsfrom HIPT. Given that our subjects were following a Paleo-lithic diet, we cannot relate all of the observed weight loss toHIPT training. However, HIPTand Paleolithic diet in com-bination could be used to promote positive changes in bodycomposition.Additionally, these ndings could be signicant forathletes wishing to improve their aerobic performance.Althoughan aerobic training regimenbased is primarilyon long slow endurance workouts, for example (cycling andrunningfor extendedperiodsat moderateintensity,70%V_ O2max), we propose that HIPT training could be used as anadjunct to this strategy in light of our ndings. Furthermore,HIPT workoutsrequiremuchlesstimespenttrainingthantraditionalaerobicexerciseandcouldserveasaconvenientand practical addition to a training regimen focused onimprovement of aerobic tness or body composition inhealthyadults.REFERENCES1. Bergeron, MF, Nindl, BC, Deuster, PA, Baumgartner, N, Kane, SF,Kraemer, WJ, Sexauer, LR, Thompson, WR, and OConnor, FG.Consortium for Health and Military Performance and AmericanCollege of Sports Medicine consensus paper on extreme conditioningprograms in military personnel. Curr Sports Med Rep 10: 383389, 2011.2. Biaggi, RR, Vollman, MW, Nies, MA, Brener, CE, Flakoll, PJ,Levenhagen, DK, Sun, M, Karabulut, Z, and Chen, KY. Comparisonofair-displacementplethysmographywith hydrostatic weighingandbioelectricalimpedanceanalysis forthe assessment ofbodycomposition in healthy adults. Am J Clin Nutr 69: 898903, 1999.3. Blair, SN, Kohl, HW 3rd, Paffenbarger, RS Jr, Clark, DG, Cooper, KH,and Gibbons, LW. Physical tness and all-cause mortality. A prospectivestudy of healthy men and women. J Am Med Assoc 262: 23952401, 1989.4. Bruce, RA and Hornsten, TR. Exercise stress testing in evaluation ofpatients with ischemic heart disease. Prog Cardiovasc Dis11: 371390, 1969.5. Burgomaster, KA, Hughes, SC, Heigenhauser, GJ, Bradwell, SN, andGibala, MJ. Six sessions of sprintinterval training increases muscleoxidative potential and cycle endurance capacity in humans. J ApplPhysiol98:19851990, 2005.6. Crouter, SE, Antczak, A, Hudak, JR, DellaValle, DM, and Haas, JD.Accuracy and reliability of the ParvoMedicsTrueOne 2400andMedGraphics VO2000metabolic systems. Eur J Appl Physiol98:139151, 2006.7. Dempster, P and Aitkens, S. A new air displacement method for thedetermination of human body composition. Med Sci Sports Exerc 27:16921697, 1995.8. Hawkins, MN, Raven, PB, Snell, PG, Stray-Gundersen, J, andLevine, BD. Maximal oxygen uptake as aparametric measure ofcardiorespiratorycapacity. Med Sci Sports Exerc 39: 103107, 2007.9. Kilding, AE, Wood, M, Sequira, G, andBonetti, DL. Effect ofhyperoxic-supplemented interval training on enduranceperformance in trained cyclists. Int J Sports Med 33: 359363, 2012.10. Osterdahl, M, Kocturk, T, Koochek, A, and Wandell, PE. Effects ofashort-term intervention witha paleolithic dietin healthyvolunteers. Eur J Clin Nutr 62: 682685, 2008.11. Perry, CG, Talanian, JL, Heigenhauser, GJ, and Spriet, LL.Theeffectsof training in hyperoxia vs. normoxia onskeletal muscleenzyme activities and exercise performance. J Appl Physiol 102:10221027, 2007.12. Siri, WE. Body composition from uid spaces and density: Analysisofmethods. 1961. Nutrition 9: 480491, 1993;discussion 480, 492,1993.13. Tremblay, A,Simoneau, JA, andBouchard, C.Impact of exerciseintensity on bodyfatness andskeletal muscle metabolism. MetabClin Exp 43: 814818, 1994.14. Trilk, JL, Singhal, A, Bigelman, KA, and Cureton, KJ. Effect of sprintinterval training on circulatory function during exercise in sedentary,overweight/obese women. Eur J Appl Physiol 111: 15911597, 2011.CrosstTrainingImprovesAerobicFitnessandBodyComposition3172 Journal of Strength and Conditioning Researchthe TMCopyright National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.