Adapted Chester Step Test can have maximal response characteristics for the assessment of exercise capacity in young women

heal hca e A icle Adap ed Ches e S ep Tes Can Ha e Maximal Response Cha ac e is ics o he Assessmen o Exe cise Capaci y in Young Women Rui Vila inho 1,2,* , Ana Ri a Mendes 3, Ma iana Gomes 3, Rui Fe ei a 3, Fabíola Cos a 3, Ma cela Machado 3, Má cia Ne es 3, Cá ia Canei as 2,4 and An ónio Mesqui a Mon es 1,5   Ci a ion: Vila inho, R.; Mendes, A.R.; Gomes, M.; Fe ei a, R.; Cos a, F.; Machado, M.; Ne es, M.; Canei as, C.; Mon es, A.M. Adap ed Ches e S ep Tes Can Ha e Maximal Response Cha ac e is ics o he Assessmen o Exe cise Capaci y in Young Women. Heal hca e 2021,9, 308. h ps:// doi.o g/10.3390/heal hca e9030308 Recei ed: 7 Feb ua y 2021 Accep ed: 7 Ma ch 2021 Published: 10 Ma ch 2021 Publishe ’s No e: MDPI s ays neu al wi h ega d o ju isdic ional claims in published maps and ins i u ional a il- ia ions. Copy igh : © 2021 by he au ho s. Licensee MDPI, Basel, Swi ze land. This a icle is an open access a icle dis ibu ed unde he e ms and condi ions o he C ea i e Commons A ibu ion (CC BY) license (h ps:// c ea i ecommons.o g/licenses/by/ 4.0/). 1Cen e o Rehabili a ion Resea ch (CIR), Depa men o Physio he apy, Poly echnic Ins i u e o Po o, School o Heal h, 4200-072 Po o, Po ugal; [email p o ec ed] 2Heal hca e Depa men , Nippon Gases Po ugal, 2600-242 Lisbon, Po ugal; [email p o ec ed] 3P i a e P ac ice, Poly echnic Ins i u e o Po o, School o Heal h, 4200-072 Po o, Po ugal; [email p o ec ed] (A.R.M.); [email p o ec ed] (M.G.); [email p o ec ed] (R.F.); [email p o ec ed] (F.C.); [email p o ec ed] (M.M.); [email p o ec ed] (M.N.) 4Mic obiology Resea ch Labo a o y on En i onmen al Heal h (En iHeal hMic oLab), Facul y o Medicine, Ins i u e o En i onmen al Heal h (ISAMB), Uni e si y o Lisbon, 1649-028 Lisbon, Po ugal 5Depa men o Physio he apy, San a Ma ia Heal h School, 4049-024 Po o, Po ugal *Co espondence: [email p o ec ed]; Tel.: +351-222-061-000 Abs ac : Ches e s ep es (CST) es ima es he exe cise capaci y h ough a submaximal esponse, which can limi i s applica ion in he p esc ip ion o exe cise. This s udy aimed o assess whe he an adap a ion o he CST (wi h a p og essi e p o ile) can ha e maximal esponse cha ac e is ics in young women and compa e i o he inc emen al shu le walk es (ISWT). Ano he aim was o de e mine i s wi hin-day es – e es eliabili y. A c oss-sec ional s udy was conduc ed wi h 25 women ( 20.3 ±1.5 yea s ) who pe o med he ield es s wice on wo di e en days (48 h apa ). The maximal e o a ainmen was assessed by he hea a e (HR), pe cep ion o exe ion (Bo g scale), and blood lac a e concen a ion. Fo he pe o mance a iables, Pea son’s co ela ion and in aclass co ela ion coe icien (ICC 2,1 ) we e used. In he bes es , mean alues o maximal esponse we e obse ed in he adap ed CST (94.0 ± 6.5% o age-p edic ed HR max , 11.3 ± 4.5 mmol/dl o blood lac a e, and 18.4 ±1.5 o Bo g a ing). The co ela ions be ween he adap ed CST and he ISWT we e weak o mode a e (0.38 ≤ ≤ 0.55; p< 0.05). Fai o good eliabili y was ound o he adap ed CST (ICC2,1 = 0.48–0.61 ). The adap ed CST showed mean alues o maximal esponse, weak o mode a e associa ion wi h he ISWT, and low wi hin-day es – e es eliabili y in young women. Keywo ds: ca dio espi a o y i ness; exe cise p esc ip ion; maximal e o ; physical i ness; s ep es 1. In oduc ion The concep o exe cise capaci y includes he physiological maximal esponse o an exe cise ole ance es wi h he assessmen o ca dio espi a o y i ness [ 1 , 2 ]. S ep es ing is one o he mos inexpensi e and easible op ions o assess exe cise capaci y [ 3 ]. Howe e , mos s ep es s we e de eloped o es ima e he exe cise capaci y h ough submaximal esponses [ 4 ]. An adap a ion o he Ches e s ep es (CST), a submaximal s ep es [ 5 , 6 ], o a new and p og essi e es can be a good op ion o explo e. Fu he mo e, a p og essi e es allows he p esc ip ion o exe cise, especially endu ance aining, h ough i s maximal wo k a e achie ed [ 3 , 7 , 8 ]. Taking as example he inc emen al shu le walk es (ISWT) [ 9 ], his alid ield es can e lec he maximal ca dio espi a o y esponse p o oked by a ca diopulmona y exe cise es (CPET) [ 10 – 12 ] allowing he p esc ip ion o exe cise [ 3 ]. The e o e, i is impo an o con i m in a new and p og essi e ield es whe he i s peak wo k a e in pe o mance e lec s a maximal physiological esponse. Heal hca e 2021,9, 308. h ps://doi.o g/10.3390/heal hca e9030308 h ps://www.mdpi.com/jou nal/heal hca e Heal hca e 2021,9, 308 2 o 10 The measu emen o maximal oxygen up ake (VO 2 max), wi h he e i ica ion o i s pla eau, is he mos impo an a iable o assess he physiological maximal esponse [3,8,13] . Howe e , when i is no e i ied, a clus e o o he a iables can be used o e i y he maxi- mal esponse o a es , such as he espi a o y exchange a io (RER) peak, he achie emen o he age-p edic ed hea a e (HR) maximum, he blood lac a e concen a ion, and he a ing pe cep ion o exe ion [ 3 , 14 , 15 ]. The assessmen o HR, blood lac a e, and pe cep ion o exe ion can be conside ed a simple , inexpensi e, and no ime-consuming clus e o measu es o con i m maximal esponse. The e o e, he aim o he p esen s udy was o assess whe he an adap a ion o he CST can ha e maximal esponse cha ac e is ics, h ough he maximum HR, blood lac a e concen a ion, and a ing pe cep ion o exe ion in young adul s, and compa e i o he ISWT. Ano he aim was o de e mine and compa e he wi hin-day es – e es eliabili y o he adap ed CST o he ISWT. The hypo hesis is ha he adap ed CST can be conside ed a maximum es wi h a good co ela ion wi h he ISWT, bu hei physiological esponses may be di e en because o hei dis inc modes o es ing (s epping s. walking). Consequen ly, di e en physiological esponses can a ec he eliabili y alues o he es s. 2. Ma e ials and Me hods 2.1. S udy Design, Rec ui men , and S udy C i e ia A c oss-sec ional design s udy was de eloped in ol ing olun ee s’ s uden s (young adul s) om a uni e si y. The s udy was ad e ised a he uni e si y, h ough emails sen o he s uden s’ ins i u ional accoun s, so in e es ed pa icipan s could con ac he esea ch eam di ec ly. Only young adul s we e ec ui ed o educe he p obabili y o excluding in e es ed pa icipan s wi h disabili ies and acu e o ch onic diseases since hei p e alence inc ease wi h age [ 16 ] and ha hey can in luence he maximal esponse o an exe cise es [ 3 ]. The e o e, eligibili y c i e ia we e: age be ween 18 and 30 yea s, bo h gende s, body mass index be ween 18.5 and 29.9 kg/m 2 ; and physically inac i e (who did no pe o m physical ac i i y o 30 min o mo e a leas h ee imes pe week) [ 3 ]. Pa icipan s wi h sel - epo o acu e o ch onic diseases, smoking habi s, p egnan women, lu-like symp oms, o espi a o y in ec ion up o ou weeks be o e he s udy, and cu en ly use o any ype o medica ion we e excluded. This s udy ecei ed e hical app o al by a Resea ch E hics Commi ee and w i en in o med consen (Decla a ion o Helsinki) was ob ained om all pa icipan s. 2.2. Measu es The s udy was pe o med be ween Janua y and May o 2019. Each pa icipan pe - o med he adap ed CST and he ISWT on di e en days (48 h apa ), andomly. The o al ime o each collec ion day o each pa icipan was one hou . Each ield es was pe o med wice ( es 1 and es 2) wi h a es in e al o a leas 30 min. Speci ic ins uc ions we e gi en o he pa icipan s: a oid physical ac i i y and any in ake o ca eine and alcohol in he 24 h p io o es ing, o ge a leas 8 h o sleep he nigh be o e, o ea a ligh meal and o inges 500 mL o wa e in he wo hou s be o e he es s. Since he s udy was conduc ed du ing a pe iod o classes, i was no possible o pe o m he es s a he same pe iod o he day o all pa icipan s. In addi ion, on he i s day, he i s p ocedu e was he assessmen o he body composi ion wi h a segmen al bioelec ical impedance analysis (Tani a BC-545 N, Tani a, Ams e dam, The Ne he lands), by weigh , body mass index (BMI), body a pe cen age, and muscle mass measu es. Fo hese measu es, pa icipan s emp ied hei bladde immedia ely be o e he s a o he measu emen s. Howe e , he absence o ood o liquid in ake o a leas 2 h be o e he measu emen s was no possible. 2.3. The Adap ed Ches e S ep Tes and he Inc emen al Shu le Walk Tes The ISWT was pe o med acco ding o he Ame ican Tho acic Socie y ecommenda- ions [ 9 ] using a 10-m co ido . Howe e , a p o ocol o 15 le els was used (1500 m) o Heal hca e 2021,9, 308 3 o 10 e alua e adul s wi hou disabili ies, o p e en he ceiling e ec [ 10 ]. The es was inished when he pa icipan was no able o main ain he equi ed speed (mo e han 0.5 m om he cone), when eques ed by he pa icipan , o o some o he epo ed symp oms o exe ion in ole ance (dyspnea, leg a igue, dizziness, e igo) [9]. In i s u n, ou s ep es was adap ed om he CST [ 5 , 6 ], using a Max Ae obic s ep (Mambo, Tissel , Belgium), wi h a 0.2 m heigh . The o iginal es has 5 le els, each o 2 min du a ion, and he s ep wo k a e is se wi h a me onome, which s a s a 15 s eps/min and inc eases by 5 s eps/min e e y 2 min: s age 1 (15 s eps/min), s age 2 (20 s eps/min), s age 3 (25 s eps/min), s age 4 (30 s eps/min), and s age 5 (35 s eps/min). Fo he adap a ion, i was applied he same ini ial s ep wo k a e as he Ches e s ep es (15 s eps/min), bu he inc emen in e e y 2 min was only by 2 s ep/min. I was also added he same numbe o le els as he inc emen al shu le walk es (15 le els), wi h a maximum wo k a e achie able o 43 s ep/min. The c i e ia o s op he es we e: no able o main ain he equi ed wo k a e o 10 s, eques ed by he pa icipan , o o some o he epo ed symp oms o exe ion in ole ance (dyspnea, leg a igue, dizziness, and e igo) [5,6]. 2.4. Measu emen s du ing he Adap ed Ches e S ep Tes S ep and he Inc emen al Shu le Walk Tes HR and pe cep ion o exe ion we e moni o ed a es and du ing each ield es using a ca dio equencime e (Pola ® FT7, Oy, Finland), and a Bo g Ra ing o Pe cei ed Exe ion Scale ( ange 6–20) [ 17 ], espec i ely. Pa icipan s we e asked o a e hei exe ion on he Bo g scale combining all sensa ions and eelings o physical s ess and a igue, dis ega ding any one ac o such as leg pain o sho ness o b ea h [ 18 ]. Fo he analysis o he esul s, HR and pe cep ion o exe ion was eco ded immedia ely a e he end o each es . P edic ed maximum HR (HR max ) was calcula ed by he equa ion HRmax = 220 − age [ 19 ], o he calcula ion o he age-p edic ed HR max (%). Blood samples we e d awn immedia ely a e each es by inge -p ick capilla y using a lance and coded yellow es s ip wi h a eagen chemical subs ance. Blood lac a e was analysed by pho ome y (Accu end ® , Roche Diagnos ics, Basel, Swi ze land) [20]. The pe o mance a iables o he adap ed CST we e he numbe o s eps (p ima y ou come), maximum wo k a e eached, and o al es ime. In i s u n, he pe o mance a iables o he ISWT we e he dis ance (p ima y ou come), gai speed eached, and o al es ime. These pe o mance a iables we e eco ded and p esen ed acco ding o he bes es pe o med by he pa icipan s, and also in he i s and second a emp s ( es 1 and es 2). T ained physio he apis s, wi h expe ience in applying hese es s, collec ed he da a. 2.5. Da a, S a is ical Analysis Desc ip i e and in e en ial s a is ical analysis was pe o med using he IBM’s S a is i- cal Package o he Social Science ® so wa e, e sion 26.0 (IBM Co po a ion, Chicago, IL, USA), wi h a signi icance se a 0.05. All a iables we e es ed o no mali y using Shapi o– Wilk es . Desc ip i e da a was exp essed as mean (s anda d de ia ion) o quan i a i e a iables, and absolu e and ela i e equencies o quali a i e a iables. Maximal e o a ainmen o he adap ed CST and he ISWT was analyzed wi h he manda o y ul illmen o he ollowing h ee c i e ia sugges ed by he li e a u e: (1) a ainmen o age-p edic ed maximum hea a e (HR max ) > 90%; (2) pos -exe cise blood lac a e concen a ion > 8 mmol/dL; and (3) a Bo g Ra ing o Pe cei ed Exe ion >17 [ 3 , 14 , 15 ]. Pai ed - es was used o e alua e wi hin-g oup di e ences o pe o mance and maxi- mal e o a ainmen be ween es 1 and es 2 o each ield es . The same s a is ical es was used o analyze he di e ences in maximal e o be ween ield es s, in he bes es , in es 1 and in es 2. Pea son’s co ela ion coe icien s we e calcula ed be ween he adap ed CST and he ISWT in hei bes es . The s eng h o co ela ions has been classi ied acco ding o B i ish Medical Jou nal guidelines, which ega d signi ican co ela ion coe icien s o 0–0.19 as Heal hca e 2021,9, 308 4 o 10 e y weak, 0.2–0.39 as weak, 0.4–0.59 as mode a e, 0.6–0.79 as s ong, and 0.80–1 as e y s ong [21]. The sample size was no calcula ed p io o his s udy. Howe e , o he associa ion o he adap ed CST o he ISWT, we ake in o conside a ion he ecommenda ion o Da id (1938), as ci ed in Bonne and W igh (2000), whe e he use o Pea son’s co ela ion can be used only i he sample size is equal o supe io o 25 [22]. Rela i e and absolu e wi hin-day es – e es eliabili y was de e mined o he aCST and ISWT pe o mances. Rela i e eliabili y be ween es s ( es 1 and es 2) was de e mined by in aclass co ela ion coe icien (ICC) model 2 ( wo-way andom e ec s), absolu e ag eemen , wi h a single a e (ICC 2,1 ), and wi h 95% con idence in e als [ 23 ]. ICC 2,1 alues we e assigned as ollows: mo e han 0.75 = excellen , 0.40–0.75 = ai o good, and less han 0.40 = poo [ 24 ]. Absolu e eliabili y was de e mined by he s anda d e o o measu emen (SEM), and he smalles eal di e ence (SRD) [25]. These wo las measu es also we e exp essed as pe cen ages (%SEM and %SRD). The SEM was calcula ed using he equa ion: SEM = SD ×√(1 −ICC) (1) whe e SD is he s anda d de ia ion o he pe o mances ob ained om all pa icipan s, and ICC is he in a a e eliabili y coe icien . The %SEM was calcula ed as %SEM = (SEM/mean) ×100 (2) whe e “mean” is he mean o he pe o mances ob ained in es 1 and es 2. The SRD a he 95% le el o con idence was calcula ed using he equa ion: SRD = 1.96 ×SEM ×√2 (3) The %SRD was calcula ed as %SRD = (SRD/mean) ×100 (4) whe e “mean” is he mean o he pe o mances ob ained in es 1 and es 2. An %SRD below 30% has been sugges ed as an accep able le el o eliabili y [26]. 3. Resul s O he 68 olun ee s, 27 pa icipan s (25 emales and 2 males) comple ed da a collec- ion. A o al o 41 pa icipan s we e excluded due o hei physical ac i i y le els (n= 20), sel - epo o ch onic diseases (n= 10), lu-like symp oms in he pas ou weeks (n= 6), and smoking habi s (n= 5). Due o he p edominance o emale pa icipan s, he 2 males we e excluded om he analysis o he esul s. Pa icipan s’ cha ac e is ics (n= 25) a e shown in Table 1. The mean BMI was classi ied as no mal, acco ding o Wo ld Heal h O ganiza ion c i e ia [27]. Table 1. Gene al cha ac e is ics o pa icipan s (n= 25). Cha ac e is ics Young Women Mean ±SD Age (yea s) 20.3 ±1.5 Body mass (kg) 61.7 ±9.7 Heigh (m) 1.7 ±0.1 BMI (kg/m2)22.4 ±2.6 To al a mass (%) 25.4 ±6.2 Lean mass (kg) 43.3 ±3.9 Da a a e exp essed as mean ±s anda d de ia ion. BMI, body mass index. Heal hca e 2021,9, 308 5 o 10 3.1. Pe o mance and Maximal E o A ainmen o adap ed Ches e S ep Tes and Inc emen al Shu le Walk Tes The mean alues o pe o mance and maximal e o o he adap ed CST and he ISWT a e p esen ed in Table 2. The pe o mance alues we e signi ican ly highe in es 1 in bo h es s (p< 0.001). All pa icipan s pe o med be e in es 1 in he adap ed CST, and 23 pa icipan s (92%) pe o med be e in es 1 in he ISWT. Table 2. Pe o mance and maximal e o a ainmen esul s o he adap ed Ches e s ep es and inc emen al shu le walk es . Adap ed Ches e S ep Tes Bes Tes Mean ±SD Tes 1 Mean ±SD Tes 2 Mean ±SD pValue be ween Tes 1 and Tes 2 Pe o mance Numbe o s eps To al es ime es (minu es) 602.8 ±103.3 602.8 ±103.3 523.5 ±87.9 <0.001 23.0 ±2.8 23.0 ±2.8 21.2 ±2.5 <0.001 Le el eached 11.2 ±1.4 11.2 ±1.4 10.3 ±1.3 <0.001 Maximal e o a iables HRmax (% p edic ed) 94.0 ±6.5 94.0 ±6.5 91.1 ±6.0 0.001 HRmax (bpm) 187.7 ±13.0 187.7 ±13.0 182.0 ±12.3 0.001 Blood lac a e (mmol/dl) 11.3 ±4.5 11.3 ±4.5 10.0 ±4.5 0.236 Bo g a ing 18.4 ±1.5 18.4 ±1.5 17.9 ±1.9 0.103 Inc emen al Shu le Walk Tes Bes es Mean ±SD Tes 1 Mean ±SD Tes 2 Mean ±SD pValue be ween Tes 1 and Tes 2 Pe o mance Dis ance (m) 1066.2 ±149.9 1059.9 ±137.1 1011.0 ±136.5 <0.001 To al es ime es (minu es) 12.2 ±1.0 12.1 ±1.0 11.9 ±0.9 <0.001 Le el eached 11.8 ±1.0 11.8 ±1.1 11.6 ±0.9 0.06 Maximal e o a iables HRmax (% p edic ed) 97.6 ±3.6 * 97.4 ±3.8 * 96.6 ±3.3 * 0.06 HRmax (bpm) 194.9 ±7.2 * 194.4 ±7.6 * 193.0 ±6.7 * 0.06 Blood lac a e (mmol/dl) 9.0 ±3.0 * 8.9 ±3.1 * 8.9 ±3.5 0.898 Bo g a ing 18.0 ±1.4 18.0 ±1.5 17.2 ±1.9 0.08 Da a a e exp essed as mean ± s anda d de ia ion. HR max : maximum hea a e. * p< 0,05 o compa isons be ween he adap ed Ches e s ep es and inc emen al shu le walk es in he bes es , in es 1, and in es 2. Gi ing he c i e ia sugges ed by he li e a u e and acco ding o hei mean alues, maximal e o a ainmen was obse ed in he bes es , in es 1, and in es 2 o each ield es (Table 2). Signi ican di e ences we e ound in he a ainmen o age-p edic ed HR max be ween es 1 and es 2 in he adap ed CST (p= 0.001). Howe e , he ul illmen o he h ee c i e ia o maximal e o in he adap ed CST es was obse ed in 19 pa icipan s (76%) in he bes es , 19 pa icipan s (76%) in es 1, and 13 pa icipan s (52%) in es 2. In he ISWT, he ul illmen o he h ee c i e ia o maximal e o was obse ed in 20 pa icipan s (80%) in he bes es , 18 pa icipan s (72%) in es 1, and 14 pa icipan s (56%) in es 2 (Table 2). Compa ing he maximal e o be ween he wo modes o es ing in he bes es , HR was signi ican ly highe in ISWT (p< 0.001), blood lac a e concen a ion was signi ican ly highe in he adap ed CST (p= 0.03), bu no signi ican di e ences we e obse ed in Bo g a ing. In es 1, HR was signi ican ly highe in ISWT (p= 0.003), blood lac a e concen a ion was highe in he adap ed CST (p= 0.04), bu no signi ican di e ences we e obse ed in Bo g a ing (p= 0.273). On he o he hand, in es 2, HR was signi ican ly highe in ISWT ( p< 0.001 ), bu no signi ican di e ences we e obse ed in blood lac a e concen a ion (p= 0.312), and in Bo g a ing (p= 0.08) (Table 2). 3.2. Co ela ions be ween he Tes s and In aclass Co ela ion Coe icien Values Table 3shows he co ela ions be ween he bes es o he adap ed CST (numbe o s eps and le el eached) and he ISWT (dis ance and le el eached). These a iables had signi ican posi i e co ela ions classi ied as weak and mode a e (0.38 ≤ ≤ 0.55; p< 0.05) (Table 3). Heal hca e 2021,9, 308 6 o 10 Table 3. Co ela ions be ween he bes pe o mance o he adap ed Ches e s ep es and inc emen al shu le walk es . Va iables pValue aCST numbe o s eps and ISWT dis ance 0.40 0.04 aCST le el eached and ISWT dis ance 0.55 0.005 aCST numbe o s eps and ISWT le el 0.38 0.04 aCST le el eached and ISWT le el 0.51 0.01 aCST, adap ed Ches e s ep es ; ISWT, inc emen al shu le walk es . Table 4p esen s he ela i e and absolu e eliabili y esul s o he aCST and ISWT. Acco ding o ICC 2,1 alues, we ound ai o good wi hin-day es – e es eliabili y o he adap ed CST, and excellen wi hin-day es – e es eliabili y o he ISWT. Acco ding o he %SRD, he aCST (numbe o s eps) p esen ed a alue highe han 30% sugges ing an unaccep able le el o eliabili y (Table 4). Table 4. Resul s o eliabili y measu es o he adap ed Ches e s ep es and inc emen al shu le walk es . Va iables ICC2,1 (95% CI) SEM SEM (%) SRD SRD (%) Adap ed Ches e S ep Tes Numbe o s eps 0.48 (0.03 o 0.76) * 72.3 12.8 200.4 35.6 To al es ime (min) 0.61 (0.04 o 0.85) * 1.7 7.7 4.7 21.3 Inc emen al Shu le Walk Tes Dis ance (m) 0.90 (0.27 o 0.97) * 42.7 4.1 118.4 11.4 To al es ime (min) 0.87 (0.50 o 0.96) * 0.33 2.8 0.91 7.6 ICC, in aclass co ela ion coe icien ; SEM, s anda d e o o measu emen ; SRD, smalles eal di e ence. *p< 0.001. 4. Discussion One o he main esul s o he p esen s udy showed ha he adap ed CST had mean alues o maximal physiological esponse in young women. This inding sugges s ha his adap a ion can be used o assess exe cise capaci y and an al e na i e o p esc ibe exe cise aining h ough he maximal wo k a e. To he bes o ou knowledge, his was he i s s udy o obse e he maximal e o a ainmen in an adap ed s ep es by using he clus e o measu es HR, blood lac a e, and Bo g a ing [ 3 , 14 , 15 ]. Howe e , i is impo an o men ion ha some pa icipan s did no each he maximal e o in ou adap ed CST, as well as in he ISWT. The physical inac i i y o he pa icipan s may be one o he main ac o s which con ibu es o ea ly-onse a igue and o he symp oms (i.e., muscle and join pain) [ 28 ], which leads o he inabili y o main ain he equi ed wo k a e, and, consequen ly, in e up ion o he es s be o e ob aining maximal e o . The di e ences ound be ween he adap ed CST and he ISWT in hei physiological esponses we e expec ed due o he dis inc modes o es ing and also by he ype o a iables used in he clus e o measu es, whe e a cen al a iable (HR) and a pe iphe al a iable (blood lac a e) o he ca diopulmona y sys em we e included [ 3 , 29 , 30 ]. S epping ask, as he s ai -ascending, equi es a high capaci y o he la ge high muscles, especially he quad iceps, o bea he whole body weigh agains g a i y [ 31 ]. The highe blood lac a e concen a ion obse ed in he adap ed CST may e lec his equi emen and also sugges s g ea e ec ui men o ype II ibe s ( as - wi ch) in his modali y, since his ype o ibe s a e p edisposed o p oduce la ge quan i ies o lac a e han ype I (slow- wi ch) ibe s [ 32 ]. Addi ionally, a high blood lac a e concen a ion e lec s mo e pe iphe al ac i i y, as muscle me abolism [ 33 ], a he han ci cula o y esponses which a e mo e de ec ed by he aise o ca diac a iables, like he HR. The e o e, acco ding o he ISWT esponse, i s highe HR achie emen sugges s a highe cen al demand in he ca diopulmona y sys em [ 34 ]. Despi e hese esul s, no di e ence in Bo g a ing was e i ied be ween he es s, which indica es ha he es s ep esen ed he same pe cei ed gene al e o by he young women. This inding is explained by he ins uc ions applied in he Bo g scale, whe e pa icipan s Heal hca e 2021,9, 308 7 o 10 we e asked o a e hei exe ion combining all sensa ions and eelings o physical s ess and a igue, dis ega ding any one ac o such as leg pain o sho ness o b ea h [18,35]. One o ou in e es s in he de elopmen o his s udy was also o explo e he asso- cia ion be ween he adap ed CST wi h he ISWT since his las one p esen s consis en measu emen p ope ies and p oduces a maximal ca dio espi a o y esponse [ 10 – 12 , 36 ]. Howe e , al hough ou esul s demons a e ha hese es s a e associa ed, hei co ela ions we e weak o mode a e. Ano he main esul o ou s udy showed ha he ela i e eliabili y o he adap ed CST was ai o good (ICC 2,1 ), was lowe han he ISWT, and wi h an unaccep able le el o absolu e eliabili y (%SRD), which means ha i s pe o mance was no ep oducible. Fu he mo e, no lea ning e ec was obse ed since he mean alues o pe o mance we e highe in es 1. E en so, we obse ed mean alues o maximal e o al eady in es 1, which indica es ha some young women we e able o achie e a maximal esponse wi hou a amilia iza ion o he es . The e o e, we sugges ha one a emp o he adap ed CST seems o be enough o assess exe cise capaci y, bu he con i ma ion o i s maximal esponse is necessa y. The leng h o he es (bes es : 23 min) and he high epe i i e and in ensi e s epping o he adap ed CST, especially a he end o he es , can explain he lowe eliabili y by he possible inadequa e compliance o pa icipan s on he second epe i ion, due o i s demanding biomechanical ask. The pe o mance o his es can causes high con ac o ces on join s, especially on he knees, which, consequen ly, demands he p oduc ion o g ea e local muscula exe ions when compa ed o walking/ unning [ 31 ]. The e o e, his g ea e exe ion can cause mo e local muscle a igue, especially in seden a y pa icipan s, and limi he pe o mance o a second epe i ion o he adap ed CST. Acco ding o hese indings, we sugges ha he es in e al be ween a emp s (30 min) in he adap ed CST may no be su icien , so, mo e ime may be needed o ob ain be e eliabili y alues. These low eliabili y alues ound in he adap ed CST do no e lec he e idence, whe e highe alues o he wi hin-day eliabili y we e obse ed in o he s ep es s, espe- cially o he 6-min s ep es in heal hy adul s (ICC = 0.88–0.90) [ 37 , 38 ]. One explana ion is he di e en ypes o es s, whe e he 6-min s ep es is conside ed a submaximal es , so he e i ica ion o maximal e o a ainmen , especially highe blood lac a e concen- a ion, is less obse ed. The submaximal cha ac e is ic also p o ides no di e ences in pe o mance (numbe o s eps) be ween a emp s o he 6-min s ep es , and, consequen ly, no lea ning e ec [ 37 , 38 ]. Ano he obse a ion is ha s ep es pe o mances in disease popula ions, especially in ch onic obs uc i e pulmona y disease (COPD), p esen ed highe ICC 2,1 alues han ou esul s (ICC > 0.91) [ 39 ]. These highe alues can be explained by he ac ha he s ep es s applied in COPD a e mos ly submaximal. On he o he hand, in e idence, he eliabili y o o he exe cise capaci y es s (e.g., 6-min walk es , and he unsuppo ed uppe limb exe cise es ) seems o be highe in disease popula ions, namely in o he ch onic lung diseases [ 40 – 43 ] and ca dio ascula diseases [ 44 , 45 ], han in heal hy o wi hou disabili ies pa icipan s [ 38 , 46 , 47 ]. One o he explana ions o hese di e ences is he ec ui men p ocess o he samples, as al eady discussed by Oli ei a and colleagues [ 46 ], whe e highe esul s can be obse ed in disease popula ions because hese pa ien s a e gene ally ec ui ed om hospi als, which a e o en mo e homogeneous in hei cha ac e is ics han people om he communi y. Howe e , in ou s udy, we ied o con ol impo an con ounde s in people ec ui ed om he uni e si y, in ol ing only young pa icipan s (18–30 yea s old), wi h BMI classi ied as no mal and o e weigh , and physically inac i e. As a limi a ion o ou adap ed CST, i s mean alue o o al es ime (bes es : 23.0 ±2.8 min ) was almos wice he ime o he ISWT (bes es : 12.2 ± 1.0 min). This obse a ion c ea es a con lic wi h he gene al ecommenda ions o he assessmen o exe cise capaci y, which, in gene al, a es las ing 8–12 min is ideal [ 14 ]. This esul , adding he sugges ion o p olong he es in e al be ween a emp s, can limi he applica ion o he adap ed CST in clinical p ac ice by equi ing mo e ime. As ano he limi a ion, he p e-s udy sample size was no calcula ed. Howe e , based on he associa ion be ween Heal hca e 2021,9, 308 8 o 10 he adap ed CST and he ISWT, a pos hoc powe analysis was conduc ed. This analysis was based on ou achie ed sample size (n= 25) and he obse ed e ec size (co ela ion be ween he p ima y ou comes o he es s: numbe o s eps on adap ed Ches e s ep Tes and dis ance on inc emen al shu le walk es , = 0.40 p= 0.04), ob aining a powe es o 0.53. Al hough he powe es could ha e been g ea e , his cu en alue allowed he e i ica ion o signi ican co ela ions be ween he pe o mances o he wo es s in hei p ima y ou comes. E en so, he gene alizabili y o ou indings has o be con i med in a la ge popula ion, including male pa icipan s, and also in a b oade ange o ages. Ano he impo an sugges ion in u u e s udies is o adap o de elop s ep es s wi h p og essi e p o iles in disease popula ions o explo e i s use ulness o assess exe cise capaci y and i s applicabili y in exe cise aining in ehabili a ion p og ams. The assessmen o in e - a e eliabili y should also be add essed in u u e s udies. 5. Conclusions The adap ed CST showed mean alues o maximal esponse, has weak o mode a e associa ion wi h he ISWT, and low wi hin-day es – e es eliabili y in young women. The e o e, a ca e ul applica ion o his es in clinical p ac ice is necessa y o he assessmen o exe cise capaci y. Fu he mo e, i equi es mo e ime o i s pe o mance han ISWT. Fu u e s udies a e impo an wi h bo h gende s and people wi h diseases o explo e i s use ulness. Au ho Con ibu ions: Concep ualiza ion, R.V. and A.M.M.; me hodology, R.V., A.R.M., M.G., R.F., F.C., M.M., M.N., and A.M.M.; so wa e, R.V., A.R.M., M.G., R.F., and A.M.M.; alida ion, R.V. and A.M.M.; o mal analysis, R.V., A.R.M., M.G., R.F., F.C., M.M., M.N., and A.M.M.; in es iga ion, R.V., A.R.M., M.G., R.F., and A.M.M.; esou ces, R.V.; da a cu a ion, R.V. and A.M.M.; w i ing—o iginal d a p epa a ion, R.V., A.R.M., M.G., R.F., F.C., M.M., and M.N.; w i ing— e iew and edi ing, C.C. and A.M.M.; isualiza ion, C.C. and A.M.M.; supe ision, C.C. and A.M.M.; p ojec adminis a ion, R.V. All au ho s ha e ead and ag eed o he published e sion o he manusc ip . Funding: This esea ch ecei ed no ex e nal unding. 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