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Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httptNiSSQlJ

ISMJ

International Journal

Original research article

The effect of walking training on respiratory function and

performance in older females

Dr Aron J Murphy PhD Dr Mark L Watsford PhD

Human Performance Laboratory School of Leisure Sport and Tourism University of TechnologySydney Australia

Abstract

Background Sarcopenia affects respiratory system function potentially decreasing thoracic cavitypressure development and exercise performance Research question To investigate the role ofwalking training on reductions in respiratory muscle strength which are conceivably due to agingType of study Randomised control study Methods Twenty-six older females (range 60-69yrs) were assessed for respiratory function respiratory muscle strength and walking performanceThirteen participants were then randomly assigned to a walking training group (WT) for eight weeksand were required to undertake three supervised walking sessions per week at 60 of the heart ratereserve value Sessions ranged from 20 to 40 minutes duration Results Following the trainingthe amount of change in respiratory muscle strength was superior in the WT group in comparison tothe control group (9 for inspiratory and expiratory strength plt005) Further the WT groupdemonstrated an improvement in treadmill walking performance of 11 (plt 005) whilst treadmillwalking performance for the controls remained unchanged Despite such improvements there wereno changes to respiratory variables measured at three submaximal velocities during the treadmillassessment Conclusions The improvement in respiratory muscle strength indicates the stronginvolvement of the respiratory system during walking training however the lack of change inrespiratory variables during submaximal walking indicates that the respiratory system may not be anexercise limiting factor in 60-69 yr-old females during submaximal tasks In contrast at elevatedwalking intensities the improved strength of the respiratory muscles may assist in a greatertolerance of the required workload Keywords elderly respiratory muscle strength quality of lifeactivities of daily living women

Dr Aron J Murphy PhD

Dr Aron Murphy is the Director of the Human Performance Laboratory at the University ofTechnology Sydney Australia His research encompasses the aging population the mechanicalproperties of the musculotendinous unit recovery from high-intensity exercise team sportperformance and software development for exercise science He has published over 40 refereedjournal papers and presented keynote addresses at several international exercise scienceconferences

bull Corresponding author Address at the end of text171 Official Journal of FIMS (International Federation of Sports Medicine)

Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 b1tb)iVNN 51 CJ1Tl

Dr Mark L Watsford PhD

Dr Mark Watsford is a lecturer in Human Movement Studies and at the University of TechnologySydney Australia His main research interests cover topics including the examination of traininginterventions for the older population physical activity and health field sport performance andmechanical properties of the musculotendinous unit He has worked as a Sport Analyst at theSydney Academy of Sport for the past 6 yearsContact detailsTel +61 295145379Fax +61 295145195Email Q2c~I lltlniuts cciu dL

Introduction

Age-related sarcopenia has been shown toimpair physical performance 1 The evidentloss of muscle strength may limit walkingvelocity 2 3 and hence the performance ofactivities of daily living 4 Furthermore thisreduction in walking ability may decrease theability to perform training at intensities thatstimulate physical fitness improvementsthus causing the individual to enter thevicious cycle of ageing 5 Females areseemingly at a greater risk of suchreductions due to reduced exerciseparticipation rates in comparison to males 6

and lower initial strength levels 7 Numerousauthors have examined the capacity forvarious training modalities to reduce theimpact of sarcopenia including strengthtraining 89 and aerobic training 10 Benefitsfor older individuals who participate inregular exercise include increased lifesatisfaction and increased quality of life incomparison to sedentary older individuals 11

improve respiratory function and walkingperformance in older women It washypothesised that the elevated ventilatoryrequirement witnessed during walkingtraining at 60 HRR would stimulate anincrease in RM function and walkingperformance in the older population

Methods

Twenty-six healthy females aged 60-69 yrs(647 plusmn 28 yr 675 plusmn 86 kg 1624 plusmn 63 cm)were recruited via advertisements to thelocal community and gave their informedconsent to participate in the research Theparticipants had a varied history of physicalactivity participation with a mean of 25sessions per week The physical activitytypically consisted of walking at a moderateintensity however several participantsreported regular participation in cyclingrunning resistance training and court sportsalbeit at a recreational level Participantswere excluded from the study if they did notreceive health clearance from their general

Walking training has been demonstrated as practitioner or were not confident to continuea viable modality to promote gains in with the testing following the familiarisationcardiovascular fitness primarily through an session in the laboratory At theincrease in leg strength aerobic enzyme commencement of the research severalconcentration blood volume and stroke participants were taking medication forvolume whilst decreasing vascular various conditions including hypertension (8resistance 101213 Despite the participants) hormone replacement therapydocumentation of these benefits there (3 participants) and arthritis (2 participants)remains a paucity of information regarding However following medical clearance suchthe function of the respiratory system and conditions were deemed to be non-influentialrespiratory muscles (RM) following aerobic to the results of the study The participantstraining The increased respiratory demand were required to perform four different testsduring exercise provides a stimulus for the on two occasions separated by a minimumdevelopment of RM strength and endurance of four days to ensure recovery The1415 which may have positive implications physiological tests included spirometry (Dayfor exercise participation in the older One) assessment of RM strength (Daypopulation Therefore the aim of the current Two) an inspiratory muscle endurance (IME)study was to elucidate if walking training at test (Day One) and an incremental treadmillan intensity of 60HRR for 20-40 minutes 3 test to a subjective intensity of hard (Daytimes per week for 8-weeks was adequate to Two) During the treadmill test walking

172 Official Journal of FIMS (International Federation of Sports Medicine)

Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httpiWVW ISIllI com

economy was assessed at three speedswhich were similar to those encounteredduring activities of daily living 45 50 and55 kmh All tests were implemented byone trained technician who offered verbalencouragement throughout Testing wasconducted on all subjects prior to and aftereight weeks of the walking trainingintervention The research was approved bythe Human Research Ethics Committee atthe University of Technology SydneyAustralia

Spirometry

Forced vital capacity (FVC) forcedexpiratory volume in one second (FEV1) andmaximum voluntary ventilation (MW) wereassessed on a spirometer (Spiro 501 BoschGermany) All spirometry procedures wereconducted using standards set by theThoracic Society of Australia and NewZealand These procedures required theperformance of at least three technicallyacceptable trials with the final three valuesobtained being within plusmn5 of each other andthe largest value used for analysis thusensuring reliability of the results 16

Inspiratory muscle endurance

An indicator of the endurance of theinspiratory muscles was assessed using thePowerlungtrade respiratory muscle trainingdevice (Powerlung USA) The Powerlungtrade

is a threshold-loading device consisting of arigid plastic tube housing two rubberplungers each held in place by a spring Inorder to produce significant airflow theparticipant must generate respiratorypressures which overcome the thresholdpressure (PTH) causing the spring tocompress and the plunger to lift off its portWhile the Powerlungtrade is able to place aresistance on both the inspiratory andexpiratory muscles the expiratory port wassealed in order to conduct a more specificexamination of IME Adjusting theinspiratory resistance control of thePowerlungtrade places more tension on thespring thereby increasing the PTH that mustbe overcome with each inspiration AU-tubemanometer was constructed and a vacuumpump used to calibrate the arbitraryresistance settings on the Powerlungtradedevices in cm of water (cmH20) Aregression analysis performed on therelationship between these calibrated valuesand the arbitrary levels indicated that thelevels on each device create a PTH thatincreases in a linear fashion ((=099)

Respiratory muscle strength

Maximal inspiratory pressure (Plmax) andmaximal expiratory pressure (PEmax) at themouth were measured as indicators of RMstrength using a portable mouth pressuregauge (Spirovis Cosmed Italy) The IME was measured using a two minuteSpirovis consists of an occluded airway incremental threshold loading (ITL) test Thewhich contains a 2mm diameter leak to reliability and validity of this test has beenprevent artificially elevated pressures being documented with strong test-retest reliabilitydeveloped by the musculature of the mouth of 090 for maximal pressure maintained forwhile the glottis is closed P

lmaxwas a complete stage 19 In a seated position

performed from residual volume and PEm

x with a nose-clip in place each participantwas performed from total lung capacity lif started the test at the same PTH (13 cmH20)Participants remained in a seated position The participants were instructed to correctlywith a nose clip in place and were required place the mouthpiece in the mouth beforeto hold the sides of the mouth during P

Emaxbeginning inspiration and to make sure that

assessment to prevent air leaking out the this breath had completely finished beforeside of the mouthpiece Participants were taking it out of the mouth for normalrequired to breathe through the mouthpiece expiration Breathing frequency (Fa) was notattempting to inhaleexhale the air as fast constrained as it has been demonstrated toand hard as possible The maximum be unnecessary during ITL 20 After inspiringpressure maintained for one second was against this resistance for two minutes therecorded All participants performed a participant underwent two minutes restminimum of three trials until several involving normal breathing and the PTH wastechnically correct efforts were made with then increased by 7 cmH20 for allthe final three values obtained being within participants Strong verbal encouragementplusmn5 of each other and the largest value was regularly given during the exerciseused for analysis The reliability of this periods This process continued until thep~ocedure has been published previously participant coul nolonger overcome the PTHwith healthy subjects 18 to generate a Significant auditory signal to


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httpwww rsrmcorn

the researchers with the airflow When threeconsecutive breaths failed to overcome thePTH the test was terminated The maximumpressure sustained for a complete twominute stage was recorded for analysis(PEND)

Walking performance test

A submaximal incremental walking test wasundertaken on a motorised treadmill (StarTrac 4500 series USA) To examine thephysiological responses to increasingexercise intensity oxygen consumption(V02) respiratory exchange ratio (RER) HRrating of perceived exertion for walking(RPEW) (Borg 6-20) 21 rating of perceivedexertion for breathing (RPEB) (Borg 6-20)and ventilatory variables were assessedThe participants performed a treadmillwalking warm-up consisting of ten minuteswalking at various comfortable speedsFollowing the warm-up the participantsreceived a detailed description of thetreadmill walking test including themeasurement variables the criteria fortermination of the test the rate ofprogression and the intricacies of thetreadmill and the testing protocol

The test commenced at 45 krnh and theparticipants were instructed to avoid usingthe handrails as much as possible If theyrequired the use of the handrailsoccasionally for balance purposes theparticipants were instructed to press inwardlyon the rails rather than hold the rails as thesupport of body weight may affect energyexpenditure The participants walked at thisspeed for three minutes During the finalminute HR RPEW and RPEB weremeasured The treadmill speed was thenincreased by 05 krnh for a further threeminutes with the assessment variablesmeasured in the final minute of each stageThe test continued in this fashion until theparticipant recorded a RPEW or RPEB of 15(RPE15) This intensity of exercise relatedto a feeling of hard on the visual Borg scaleand this time was recorded as the time-to-

174

RPE15 (TRPE15) The participants couldvolitionally terminate the test at any time Asan additional measure to ensure the exercisetolerance of the participant did not rapidlydegrade without the opportunity to terminatethe test the RPE was monitored every 30seconds once a RPEW or RPEB of 13 wasrecorded

Throughout the test the participants wererequired to respire through a Hans-Rudolphvalve permitting the assessment of expiredgases Expired gases were sampled breath-by-breath (Max-1 Physiodyne USA) andaveraged every 30 seconds during the finalminute of each stage The gas analysisequipment was calibrated immediately priorto and following each test using gases ofknown composition Measurement variablesincluded V02 RER minute ventilation (VE)

(lrnin) Fe (breaths-min) tidal volume (VT)

(mL) and inspiratory time (TI) (seconds)Furthermore to provide an examination ofthe relative respiratory demand thepercentage of MW (MW) used duringeach stage was recorded

Training

Following the pre-testing 13 participantswere randomly assigned to a walking traininggroup (WT) with the remainder acting as anon-exercising control group (CON) (Table1) The WT group undertook threesupervised walking sessions per week at60 of the HR reserve (60HRR) value Ithas been reported that 12 weeks of trainingat this intensity resulted in high adherencerates and promoted improvements inphysical fitness 2223 In the current studysession duration was increased from 20minutes to 30 minutes following Week Twoand to 40 minutes following Week SixSession duration was selected as themanipulated variable in the training designas this variable has been reported as beinRmore appropriate for the older population 4

Post testing was undertaken within four daysof the completion of the final trainingsession

Official Journal of FIMS (International Federation of Sports Medicine)

Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 htlpJNWVi Isml com

Table 1 Participant characteristics for each group Data is reported as mean plusmn 1SD followed byrange

Age (yr)

Walking Training

(n=13)

655 plusmn 26

61-69

Controls 640 plusmn 29

60-69(n=13)

Height (em) Body mass Body mass(kg) index (kgm2

)

1628 plusmn 67 673 plusmn 83 255 plusmn 33

1474-1720 570-882 217-329


1517-1700 551-826 218-306

Statistical analyses

Data analysis was conducted usingStatistical Package for the Social Sciences(SPSS) version 110 Descriptive statisticswere calculated for all variables and reportedas means plusmn 1 standard deviation (1SO) Aone-way analysis of variance (ANOVA) wasused to determine any differences betweenthe two groups at the pre-test on thedependent measures Further the HR andsubjective (RPEW and RPEB) data from thesubmaximal walking speeds was examinedwith repeated measures ANOVA todetermine whether each speed elicited asignificantly different physiological responseThe post-test data was examined fornormality of distribution and a one-wayANOVA was performed on the test datacollected at each test occasion to examineany main effects following the trainingWithin-group effects were analysed usingrepeated measures ANOVA on the pre- andpost-test results Pearsons product-momentcorrelations also were determined for thedifferences between the pre- and post-testing (delta score 11)to examine therelationships between dependent variablesFor all procedures significance wasaccepted at an alpha level of 005

Results

One-way ANOVA revealed that there wereno significant differences between thegroups at the pre-test occasion for PIPEmaxPENDor any of the walking varitl~sAdherence to the walking programme washigh with a 98 plusmn 3 session completion ratefor the WT group There were no participantdrop-outs over the course of the trainingFurthermore there were no changes to bodymass following the training or to anyspirometry variables (Table 2) One-wayANOVA revealed main effect differences for

175

the I1RM strength variables (I1P1maxp=003I1PEmaxp=003) between the WT and CONgroups following the eight week trainingperiod Further several interaction effectswere identified following the within-grouprepeated measures analysis the WT groupdemonstrated a 9 improvement in Plmax(p=002) and PEmax(p=004) following thetraining (Table 2) PENDdisplayed a 14trend to increase following the traininghowever this result failed to reach statisticalsignificance (p=006)

The performance measure for theincremental treadmill test TRPE15showed a~ignificant within-group improvement (11 )In the WT group (p=001) Accordingly themean final treadmill speed increased by 4in the WT group (p=001) (Table 3) Whenwalking economy and physiological variableswer~ assessed the sole variable to displayany Improvement was a 5 reduction in HRat 55 krnh Despite several decreasingtrends in HR RPEW and RPEB for the WTgroup there were no changes evident toother physiological or respiratory variablesmeasured during the three walking economyvelocities (Tables 4 and 5) Despite a lack oftraining-related changes repeated measuresANOVA performed on the pre-test HR andsubjective measures (RPEW and RPEB)assessed during submaximal stages of thetreadmill test revealed that each stagerequired a greater exertion than the previous(45-50 krn-h plt001 for HR RPEW andRPEB 50-55 krn-h plt001 for HR RPEWand RPEB) Furthermore Pearsonscorrelations revealed several significantrelationships between I1RM strength andvarious physiological variables (Table 6)


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 - gtI

Table 2 Spirometry results and maximum pressures developed for respiratory muscle strength and incremental threshold loading tests Data is reported asmean plusmn 1SO followed by the range of scores

FVC FEV MW Plmax PEmax PEND

PRE POST PRE POST PRE POST PRE POST PRE POST PRE POST

Walking 330 plusmn 033 326 plusmn 033 245 plusmn 026 240 plusmn 026 715 plusmn 125 758 plusmn 201 689 plusmn 172 752 plusmn 217 bull 834 plusmn 279 905 plusmn 272 bull 564 plusmn 277 640 plusmn 257training

283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)

Controls 308 plusmn 042 314 plusmn 040 227 plusmn 029 226 plusmn 032 689 plusmn 78 693plusmn71 745 plusmn 134 743 plusmn 108 880 plusmn 224 865 plusmn 209 605 plusmn 154 612plusmn134

(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820

Kev FVC forced vital capacity FEV forced expiratory volume in one second MW maximum voluntary ventilation Plmaxmaximum inspiratory pressurePEmaxmaximum expiratory pressure PENDmaximum pressure maintained for greatest complete two minute stage during IME test em H20 em waterpressure Significantly greater change than CON group Significantly different to pre-test pltO05

Table 3 Final stage results for incremental treadmill assessment Data is reported as mean plusmn 1SO followed by the range of scores

Speed (km-h) MW Total test time (s)

PRE POST PRE POST PRE POST

Walking 642 plusmn 053 669 plusmn 056 430 plusmn 128 408 plusmn 118 819 plusmn 186 909 plusmn 164 training

600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)

Controls 631 plusmn 056 632 plusmn 054 424 plusmn 103 420 plusmn 105 797 plusmn 220 827 plusmn 209

(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260

Key MW percentage of maximum voluntary ventilation used during walking Significantly different to pre-test pltO05


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 htlplWWWlsllllcom

Table 4 Cardiovascular and perceived exertion results from incremental treadmill walking assessment Data is reported as mean plusmn 1SO

HR (b-mtn) V02 (mlmiddotkg1middotmin1) RER RPEW (Borg units) RPEB (Borg units)

PRE POST PRE POST PRE POST PRE POST PRE POST

45 kmh 1073plusmn134 1039 plusmn 144 151 plusmn 25 155 plusmn 38 079 plusmn 007 081 plusmn 008 95 plusmn 21 89 plusmn 21 92 plusmn 20 92plusmn19Walkingtraining 50 krnh 1108 plusmn 136 1075 plusmn 147 157 plusmn 20 157 plusmn 26 081 plusmn 004 082 plusmn 003 112 plusmn 12 107 plusmn 19 112plusmn12 106 plusmn 21(n=13)

55 kmh1 1175 plusmn 119 1120 plusmn 134 167plusmn25 161 plusmn23 083 plusmn 004 084 plusmn 003 129plusmn14 119 plusmn 14 125 plusmn 13 119plusmn14

45 km-h 1034 plusmn 78 1032 plusmn 81 142 plusmn 27 136 plusmn 28 083 plusmn 005 082 plusmn 006 103 plusmn 17 99 plusmn 18 107plusmn10 100plusmn15Controls

50 krn-h 1092 plusmn 96 1080 plusmn 86 149 plusmn 26 145 plusmn 26 082 plusmn 005 082 plusmn 006 117 plusmn 10 113plusmn10 116 plusmn 09 112plusmn12(n=13)

55 km-h 1167plusmn84 1169plusmn80 155plusmn18 157plusmn18 084 plusmn 005 084 plusmn 006 125plusmn14 124plusmn13 126 plusmn 14 122 plusmn 12

Key HR heart rate RER respiratory exchange ratio RPEW rating of perceived exertion for walking RPEB rating of perceived exertion for breathing Significantly different to pre-test pltO05


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp171-184 1

Table 5 Respiratory variables assessed during incremental treadmill test Data is reported as mean plusmn 1SO

VE(t-rnln) MW Fa (breaths-min] VT(mL) T (s)


45 krnh 218 plusmn 40 230 plusmn 56 314plusmn81 324 plusmn 130 229 plusmn 59 258 plusmn 60 1044 plusmn 261 976 plusmn 328 125 plusmn 038 113 plusmn 036Walkingtraining 50 kmh 229 plusmn 43 233 plusmn 38 330 plusmn 86 326 plusmn 103 244 plusmn 57 260 plusmn 50 1016 plusmn 224 984 plusmn 298 118 plusmn 039 112plusmn035(n=13)

55 krn-h 249 plusmn 47 247 plusmn 43 359 plusmn 95 347plusmn110 258 plusmn 49 261 plusmn 42 1034 plusmn 268 987 plusmn 209 110 plusmn 032 104 plusmn 022

45 krnh 207plusmn57 200 plusmn 54 303 plusmn 83 291 plusmn 81 227 plusmn 52 237 plusmn 49 965 plusmn 265 959 plusmn 256 118 plusmn 029 112 plusmn 025

Controls 50 krnh 223 plusmn 64 214plusmn64 328 plusmn 106 314plusmn106 233 plusmn 61 224 plusmn 61 1021 plusmn 235 1021 plusmn 236 117 plusmn 029 118 plusmn 030(n=13)

55 krn-h 241 plusmn 59 245 plusmn 59 355 plusmn 126 360 plusmn 106 251plusmn67 262 plusmn 70 1028 plusmn 165 985 plusmn 190 108 plusmn 022 104 plusmn 031

Kev VE minute ventilation MW percentage of maximum voluntary ventilation used during walking Fa breathing frequency VT tidal volume T1

inspiratory time


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httpVjNWS~lll com

Table 6 Pearsons product-moment correlations for all participants (n=26)

6Plmax 6PEmax 6PEND 6TRPE15

lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h

Kev 1 amount of change pre- vs post-test FVC forced vital capacity FEV1 forced expiratoryvolume in one second MW maximal voluntary ventilation Plmax maximal inspiratory pressurePEmax maximal expiratory pressure PEND greatest pressure sustained for two minutes duringincremental inspiratory muscle endurance test HR heart rate RPEW rating of perceived exertionfor walking during incremental treadmill test RPEB rating of perceived exertion for breathing duringincremental treadmill test Significant correlation pltO05

Discussion in Plmaxand PEmaxreflects the involvementand the adaptation of the respiratory systemduring walking training (Table 2) Furtherthe improvement in T RPE15in the WT groupprovides evidence of an improvement inperformance following the training periodThese results support the hypothesisproposed in the current investigation


In the current study it was hypothesised thatthe elevated ventilation during walkingtraining at 60HRR would stimulate anincrease in RM function and walkingperformance in older females The evidentmain effect and within-group improvements

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Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 bLlpiWijmiddot is~1 Cl

Similar results have been previouslyreported following various forms ofcardiovascular training 14 15 however thesestudies used near maximal trainingintensities with younger participants It isunlikely that the older population couldmaintain or reach such intensities withoutrisk however the lower intensity trainingperformed in the current study was clearlysufficient to elicit a moderate training effectIn the absence of direct measurement it ishypothesised that the elevated ventilatorydrive from an increase in blood PC02 duringthe training sessions led to an elevatedrequirement for inspiratory pressuredevelopment from the RM and the ensuingtraining effect Interestingly the RM strengthresults for the WT group (which were slightlylower at the pre-test) appeared to approachthose of the CON group following thetraining One practical implication from thisfinding is that perhaps walking training has agreater effect on individuals with lower initialstrength levels allowing them to return tolevels considered as normal Howeversuch an implication remains to be confirmedas the results of one study can neitherconfirm nor dispel such an issue Theseresults show that there is scope for furtherresearch in this area

Submaximal walking performance

Despite the improvements in RM strengthcharacteristics walking training at 60HRRdid not impact upon physiological orrespiratory parameters during submaximalwalking With the exception of HR at 55krnh there were no significant changes toany of the measured variables (Tables 4 and5) A reduced HR following walking traininghas been reported previously 1225 howeverthis finding is difficult to explain using themeasured variables in this study as therewere no significant changes to V02 FsRPEW or RPEB Despite the absence ofexplanatory variables significant negativecorrelations between LlPlmax and LlHR wereevident at the sub maximal walking velocitiesindicating that as Plmax increased HR tendedto decrease In fact up to 25 of thevariance in the reduction in HR at thesesubmaximal walking speeds was related tothe change in Plmax (Table 6) Whilst there isa distinct lack of evidence proclaiming therelationship between an increase in RMstrength and a reduction in submaximal HRwithin the literature these results givesupport to the theorised relationship 2627

The 8-week training period did not have aneffect on low intensity walking performancePotentially the duration of the training periodin the current study was insufficient to elicit aspecific training response with previousresearchers using durations of up to 40minutes per session for 12 weeks to causeimprovements in aerobic fitness 23 In spiteof such issues the session and programdurations selected for the current study werebased upon standard training durationsperformed by community dwelling olderadults therefore representing typical trainingpatterns of the older population

The lack of changes to submaximalperformance in the current study indicatethat whilst walking training has the capacityto alter the strength of the RM therespiratory system does not appear to be alimiting factor to submaximal exerciseperformance in healthy 60-69 yr old femalesAccordingly it appears that the small within-group improvement in RM performancewould have minimal implications for theperformance of activities of daily living forthis age group which are usually performedat submaximal intensities This result issomewhat surprising as improved RMfunction has been linked to exertionaldyspnoea 28 and a decrease in dyspnoeawould potentially enhance exercise capacityDespite having minimal implications forwalking economy there were severalanecdotal reports from the participants ofimproved mobility and walking capacityfollowing the training Participants in the WTgroup described a greater ability to walk upflights of stairs concentrate during activitiesrequiring physical exertion such as golf andtennis and perform various tasks around thehome including gardening and cleaning Itwas reported by Larson et al 29 that thesensations of dyspnoea associated withphysical exertion does not always relate todyspnoea in the performance of activities ofdaily living Therefore in the current studythe age group assessed may not be limitedby respiratory variables during such activitieseven if they exhibit dyspnoea at the higherworkloads in excess of 55 krn-h

To improve the physiological and respiratoryresponse during low intensity walking in theolder population it appears that training atan intensity or duration above that used inthe current study is required This has clearimplications for exercise guidelines for theolder population with the selection of anappropriate intensity crucial if improvements

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Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httplwww ISlnjCOIll

in physical condition are desiredFurthermore despite the evident differencesin intensity between stages (as shown bydifferences in group mean scores for HRRPEW and RPEB between speeds 1-2 andspeeds 2-3) and the requirement of aventilatory output greater than that witnessedat rest the intensity of activity during thewalking economy assessment velocities wasperhaps of insufficient magnitude todetermine an altered respiratory responsefollowing the training This limitationhowever was not controllable in the currentstudy as the assessment velocities used inthe analysis were the only speeds that all 26participants completed during theassessment The analysis of respiratorydemand and walking economy at greatervelocities (say 60 or 65 krnh) wouldexclude many participants as this wasbeyond their TRPE15 therefore adding bias tothe results

Hard intensity walking performance

When moderate-hard intensity exercise wasexamined (up to RPE15) it appeared thatwalking training provided an adequatestimulus for improvement in walkingperformance This finding was notunexpected as there is a wealth of literatureavailable detailing the benefits of walkingtraining for walking performance especiallyin the older population 2330-34 The reasonsfor such an improvement consist ofpotentially improved leg strength and a moreefficient cardiovascular response followingthe training The improved cardiovascularresponse consists of a greater mitochondrioncontent elevated aerobic enzymeconcentration type I muscle fiberhypertrophy improved cardiac dimensionsand the ability to tolerate blood lactateassociated with a greater chemical buffercapacity 12253536 Such results probablyaccount for the anecdotal remarks in thecurrent study However due to therespiratory focus of the current study thesevariables were not measured

A further mechanism for the improvement inT RPE15 following the training period may berelated to the increase in RM performanceThe enhanced RM strength may improve thedynamics of the respiratory pump thusreducing the competition for blood flowbetween the central and peripheral sectionsof the body Accordingly it was assumedthat following the walking training such aneffect was evident permitting a greater work

output for the same physiological demand 26

27 This mechanism for performanceenhancement has been described in thenon-healthy population with an improvementin RM function assisting to enhance walkingperformance in patients with chronicobstructive pulmonary disease 3738 andheart disease 3940 Such improvementssignify potential benefits for improvedcompletion of daily tasks for members of theolder population LlPEmax was significantlycorrelated with LlTRPE15 (Table 6) indicatingthe presence of such a relationshipInterestingly LlPlmax was not correlated toinRPE15 which tends to suggest thatexpiratory muscle strength may play more ofa role in moderate-hard intensity activities inthe older population Such improvements inphysical performance are based upon areduced competition for blood flow betweenthe RM and the periphery along withreduced exertional dyspnoea Such positiveimplications may also playa role in the moreintense activities of daily living thusimpacting upon quality of life The evidentrelationship between expiratory musclestrength and walking performance indicatesthat specific training to this musculature mayassist moderate-hard walking performance inthe older population Further researchexamining this phenomenon is required

The relatively small sample size may haveaffected the apparent lack of improvement inphysical performance following the trainingperiod Even though RM function has beendemonstrated to display a moderate-largeeffect size following training physiologicalparameters such as V02 HR Fe VE and TI

display greater biological variability andhence require larger sample sizes to detectmeaningful changes It has been proposedthat a sample size of 11 per group issufficient to detect changes in RM functionfollowing training however it appears thatoutcomes with small-moderate effect sizes(-040) would require approximately 45participants to detect changes at the 80power level at an alpha level of 00541

Such participant numbers (n=90) weredeemed unfeasible in the current study dueto constraints on laboratory resources

The results of the current study suggest thatRM capacity in healthy older females is nota determinant of submaximal exerciseperformance In contrast at intensitiesassociated with an RPE of hard theimproved strength and endurance of the RMmay assist in a greater tolerance of the


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required workload Therefore one potentialmechanism for the improved TRPE15 may bethe improvement in RM strength AlthoughLlPEmax was correlated to LlTRPE15 in thecurrent study LlPlmax and LlPEND were not(Table 6) Whilst there is an argumentsuggesting that the performance of walkingtraining at 60HRR may improve moderateintensity walking performance the role ofRM function during maximal exerciseremains undetermined in this populationWhilst members of the older populationrarely approach intensities close to maximalenergy expenditure submaximalperformance is highly reliant upon maximumcapacity therefore further research isrequired to determine the role of improvedRM strength and endurance at V02max

intensity

Conclusion

Three walking sessions per week at60HRR for an 8-week period appear topositively affect RM strength in older femalesaged 60-69 yrs Such improvements appearto have concomitant effects on walkingperformance at hard walking intensitiesHowever they do not appear to be of benefitfor submaximal intensities such as thosewitnessed during the performance of someactivities of daily living This studydemonstrates the potential for the positiveeffects of a walking programme on RMfunction and functional performance in olderadults and hence the potential benefits formore intense types of daily activitiesHowever the mechanisms for such changeswere not confirmed in the current studydespite the improvement in RM strengthbeing significantly superior to the CONgroup The current results assist in thederivation of a clear set of guidelines forexercise in the older population with theintensity of the walking undertaken beinginsufficient to result in main effectimprovements Future research is requiredto examine the effects of trainingprogrammes involving greater walkingintensities the role of the RM in tasks ofmaximal intensity in the older populationand the relationship between walkingperformance and respiratory function inindividuals aged in excess of 70 years

List of non-standard characters

ls (Greek symbol) - delta This symbol hasbeen used in the article to signify the

182

amount of change between the pre- andpost-test scores

Address for correspondence

Or Aron J Murphy Human PerformanceLaboratory School of Leisure Sport andTourism University of Technology SydneyKuring-Gai Campus PO Box 222 LindfieldNSW 2070 AustraliaTel +61 295145294Fax +61 295145195Email 1ronmurphy(Q)utseduau

References

1 Roubenoff R Sarcopenia and itsimplications for the elderly Eur JClin Nutr 2000 54 Suppl 3 S40-47

2 Woollacott MH Inglin B ManchesterO Response preparation andposture control in the older adult InJoseph J (Ed) Central determinantsof age related declines in motorfunction New York NY Academy ofSciences 1988 pp42-51

3 Bassey EJ Fiatarone MA ONeillEF et al Leg extensor power andfunctional performance in very oldmen and women Clin Sci (Lond)1992 82 321-327

4 Evans WJ Campbell WWSarcopenia and age-relatedchanges in body composition andfunctional capacity J Nutr (2 Suppl)1993 123 465-468

5 Berger BG The role of physicalactivity in the life quality of olderadults In Spirduso WW Eckert HM(Ed) Physical activity and ageingChampaign III Human Kinetics1989 pp42-58

6 Plonczynski OJ Physical activitydeterminants of older women Whatinfluences activity MedSurg Nurs2003 12213-221259

7 Janssen I Heymsfield SB WangZM et al Skeletal muscle mass anddistribution in 468 men and womenaged 18-88 yr J Appl Physiol 200089 81-88

8 Hagerman FC Walsh SJ StaronRS et al Effects of high-intensityresistance training on untrainedolder men I Strengthcardiovascular and metabolicresponses J Gerontol A Bioi SciMed 2000 55 B336-B346


Walkingtrainingand respiratoryfunctionin olderfemalesInternational SportMed Journal Vol6 No32005pp 171-184I1Jlil-lWWVi51111 COIll

9 Fiatarone MA Marks EC Ryan NO 22 De Vito G Bernardi M Forte R etet al High-intensity strength training al Effects of a low intensityin nonagenarians Effects on skeletal conditioning programme on V02max

muscle JAMA 1990 263 3029- and maximal instantaneous peak3034 power in elderly women Eur J Appl

10 Hagberg JM Graves JE Limacher Physiol Occup Physiol1999 80M et al Cardiovascular responses 227-232of 70- to 79-yr-old men and women 23 Nieman DC Henson DA Gusewitchto exercise training J Appl Physiol G et al Physical activity and1989 66 2589-2594 immune function in elderly women

11 Rosenberg E Sport voluntary Med Sci Sports Exerc 1993 25 823-association involvement and 831happiness among middle aged and 24 Mazzeo RS Tanaka H Exerciseelderly Americans In McPherson B prescription for the elderly Current(Ed) Sport and aging Champaign recommendations Sports MedIII Human Kinetics 198645-52 2001 31 809-818

12 Ogawa T Spina RJ Martin WH 3rd 25 Perini R Fisher N Veicsteinas A etet al Effects of aging sex and al Aerobic training andphysical training on cardiovascular cardiovascular responses at rest andresponses to exercise Circulation during exercise in older men and1992 86 494-503 women Med Sci Sports Exerc 2002

13 Morio B Barra V Ritz P et al 34 700-708Benefit of endurance training in 26 Sheel AW Respiratory muscleelderly people over a short period is training in healthy individuals Sportsreversible Eur J Appl Physiol2000 Med 2002 32 567-58181 329-336 27 WetterTJ DempseyJA Pulmonary

14 Clanton TL Dixon GF Drake J et system and endurance exercise Inal Effects of swim training on lung Shephard RJ Astrand PO (Eds)volumes and inspiratory muscle Endurance in sport Londonconditioning J Appl Physiol 1987 Blackwell Science 2000 52-6762 39-46 28 Robertson RJ Central signals of

15 Robinson EP Kjeldgaard JM perceived exertion during dynamicImprovement in ventilatory muscle exercise Med Sci Sports Exercfunction with running J Appl Physiol 1982 14 390-3961982 52 1400-1406 29 Larson JL Covey MK Wirtz SE et

16 Enright PL Johnson LR Connett JE al Cycle ergometer and inspiratoryet al Spirometry in the Lung Health muscle training in chronicStudy 1 Methods and quality obstructive pulmonary disease Amcontrol Am Rev Respir Dis 1991 J Respir Crit Care Med 1999 160143 1215-1223 500-507

17 Clanton TL Diaz PT Clinical 30 Wong DG Rechnitzer PAassessment of the respiratory Cunningham DA et al Effect of anmuscles Phys Ther 1995 75 983- exercise program on the perception995 of exertion in males at retirement

18 Larson JL Kim MJ Reliability of Can J Sport Sci 1990 15 249-253maximal inspiratory pressure Nurs 31 Carmeli E Reznick AZ Coleman RRes 1987 36 317-319 et al Muscle strength and mass of

19 Larson JL Covey MK Berry J et al lower extremities in relation toDiscontinuous incremental threshold functional abilities in elderly adultsloading test Measure of respiratory Gerontology 2000 46 249-257muscle endurance in patients with 32 Hamdorf PA Penhall RK WalkingCOPD Chest 1999 115 60-67 with its training effects on the fitness

20 Martyn JB Moreno RH Pare PO et and activity patterns of 79-91 yearal Measurement of inspiratory old females Aust N Z J Med 1999muscle performance with 29 22-28incremental threshold loading Am 33 Grimby G Physical activity andRev Respir Dis 1987 135 919-923 effects of muscle training in the

21 Borg GA Psychophysical bases of elderly Ann Clin Res 1988 20 62-perceived exertion Med Sci Sports 66Exerc 1982 14 377-381

183 Official Journal of FIMS (International Federationof Sports Medicine)

Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 httpwww ISlnjCOIll

34 Parkkari J Natri A Kannus P et alA controlled trial of the healthbenefits of regular walking on a golfcourse Am J Med 2000 109 102-108

35 Mahler OA Cunningham LNCurfman GO Aging and exerciseperformance Clin Geriatr Med 19862 433-452

36 Ehsani AA Cardiovascularadaptions to exercise training in theelderly Fed Proc 1987 46 1840-1843

37 Sanchez Riera H MontemayorRubio T Ortega Ruiz F et alInspiratory muscle training inpatients with COPO Effect ondyspnea exercise performance andquality of life Chest 2001 120 748-756

38 Scherer TA Spengler CMOwassapian 0 et al Respiratory

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muscle endurance training in chronicobstructive pulmonary diseaseImpact on exercise capacitydyspnea and quality of life Am JRespir Crit Care Med 2000 1621709-1714

39 Oarnley GM Gray AC McClure SJet al Effects of resistive breathingon exercise capacity and diaphragmfunction in patients with ischaemicheart disease Eur J Heart Fail 19991 297-300

40 Mancini OM Henson 0 La Manca Jet al Benefit of selective respiratorymuscle training on exercise capacityin patients with chronic congestiveheart failure Circulation 1995 91320-329

41 Kraemer HC Thieman S How manysubjects Statistical power analysisin research London Sage 1987pp105-112


Walking training and respiratory function in older females International SportMed Journal Vol6 No3 2005pp 171-184 b1tb)iVNN 51 CJ1Tl

Dr Mark L Watsford PhD

Dr Mark Watsford is a lecturer in Human Movement Studies and at the University of TechnologySydney Australia His main research interests cover topics including the examination of traininginterventions for the older population physical activity and health field sport performance andmechanical properties of the musculotendinous unit He has worked as a Sport Analyst at theSydney Academy of Sport for the past 6 yearsContact detailsTel +61 295145379Fax +61 295145195Email Q2c~I lltlniuts cciu dL

Introduction

Age-related sarcopenia has been shown toimpair physical performance 1 The evidentloss of muscle strength may limit walkingvelocity 2 3 and hence the performance ofactivities of daily living 4 Furthermore thisreduction in walking ability may decrease theability to perform training at intensities thatstimulate physical fitness improvementsthus causing the individual to enter thevicious cycle of ageing 5 Females areseemingly at a greater risk of suchreductions due to reduced exerciseparticipation rates in comparison to males 6

and lower initial strength levels 7 Numerousauthors have examined the capacity forvarious training modalities to reduce theimpact of sarcopenia including strengthtraining 89 and aerobic training 10 Benefitsfor older individuals who participate inregular exercise include increased lifesatisfaction and increased quality of life incomparison to sedentary older individuals 11

improve respiratory function and walkingperformance in older women It washypothesised that the elevated ventilatoryrequirement witnessed during walkingtraining at 60 HRR would stimulate anincrease in RM function and walkingperformance in the older population

Methods

Twenty-six healthy females aged 60-69 yrs(647 plusmn 28 yr 675 plusmn 86 kg 1624 plusmn 63 cm)were recruited via advertisements to thelocal community and gave their informedconsent to participate in the research Theparticipants had a varied history of physicalactivity participation with a mean of 25sessions per week The physical activitytypically consisted of walking at a moderateintensity however several participantsreported regular participation in cyclingrunning resistance training and court sportsalbeit at a recreational level Participantswere excluded from the study if they did notreceive health clearance from their general

Walking training has been demonstrated as practitioner or were not confident to continuea viable modality to promote gains in with the testing following the familiarisationcardiovascular fitness primarily through an session in the laboratory At theincrease in leg strength aerobic enzyme commencement of the research severalconcentration blood volume and stroke participants were taking medication forvolume whilst decreasing vascular various conditions including hypertension (8resistance 101213 Despite the participants) hormone replacement therapydocumentation of these benefits there (3 participants) and arthritis (2 participants)remains a paucity of information regarding However following medical clearance suchthe function of the respiratory system and conditions were deemed to be non-influentialrespiratory muscles (RM) following aerobic to the results of the study The participantstraining The increased respiratory demand were required to perform four different testsduring exercise provides a stimulus for the on two occasions separated by a minimumdevelopment of RM strength and endurance of four days to ensure recovery The1415 which may have positive implications physiological tests included spirometry (Dayfor exercise participation in the older One) assessment of RM strength (Daypopulation Therefore the aim of the current Two) an inspiratory muscle endurance (IME)study was to elucidate if walking training at test (Day One) and an incremental treadmillan intensity of 60HRR for 20-40 minutes 3 test to a subjective intensity of hard (Daytimes per week for 8-weeks was adequate to Two) During the treadmill test walking




Spirometry


















174





Training






Age (yr)

Walking Training

(n=13)

655 plusmn 26

61-69


60-69(n=13)


)


1474-1720 570-882 217-329


1517-1700 551-826 218-306



Results


175









283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)


(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820






600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)


(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260
























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184








Spirometry


















174





Training






Age (yr)

Walking Training

(n=13)

655 plusmn 26

61-69


60-69(n=13)


)


1474-1720 570-882 217-329


1517-1700 551-826 218-306



Results


175









283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)


(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820






600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)


(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260
























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184











174





Training






Age (yr)

Walking Training

(n=13)

655 plusmn 26

61-69


60-69(n=13)


)


1474-1720 570-882 217-329


1517-1700 551-826 218-306



Results


175









283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)


(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820






600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)


(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260
























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184








Age (yr)

Walking Training

(n=13)

655 plusmn 26

61-69


60-69(n=13)


)


1474-1720 570-882 217-329


1517-1700 551-826 218-306



Results


175









283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)


(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820






600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)


(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260
























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184











283-391 273-376 192-288 182-266 543-970 513-1282 310-930 390-1220 420-1350 590-1460 190-1000 190-910(n=13)


(n=13) 224-381 230-384 187-278 179-285 570-858 581-789 500-950 530-920 420-1270 540-1300 370-910 460-820






600-750 248-628 248-560600-750 510-1020 600-1110(n = 13)


(n = 13) 600-750 600-750 190-612 203-602 450-1260 480-1260
























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184



























inspiratory time





lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184









lFVC -021 -016 003 006

lFEV1 -027 -035 -001 -019

lPEF -030 -001 -010 018

lMW 056 -003 001 010

lP1max 100 044 003 019

lPEmax 044 100 026 049

lPEND 003 026 100 005

lTRPE15 019 049 005 100

lHR 45 kmh-1 -043 -031 -033 -029

lHR 50 krn-h -053 -017 -009 -036

lHR 55 km-hmiddot1 -044 -023 -012 -035

lRPEW45 004 019 -001 -021krn-h

lRPEW50 008 001 -016 -049 km-hmiddot1

lRPEW55 006 -022 -011 -049 km-h

lRPEB 45 -001 020 021 -021krn-h

lRPEB 50 -024 -004 -007 -044 krn-h

lRPEB 55 016 -001 -008 -030krn-h





179























intensity

Conclusion




182




References
































184




























intensity

Conclusion




182




References
































184




























184






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