Functional thresholds and its association with 20- and 40 km cycling performance

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dc.contributor.advisorTerblanche, Elmarieen_ZA
dc.contributor.advisorEngelbrecht, Louiseen_ZA
dc.contributor.authorBrandt, Rieta-Marieen_ZA
dc.contributor.otherStellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Exercise, Sport and Lifestyle Medicine.en_ZA
dc.date.accessioned2022-11-22T09:13:38Z
dc.date.accessioned2023-01-16T12:49:35Z
dc.date.available2022-11-22T09:13:38Z
dc.date.available2023-01-16T12:49:35Z
dc.date.issued2022-12
dc.descriptionThesis (M Sport Sc)--Stellenbosch University, 2022.en_ZA
dc.description.abstractENGLISH ABSTRACT: Threshold Power (FTP) and Critical Power (CP) are both functional thresholds that potentially are more comprehensive measures of an athlete’s cycling endurance performance capabilities compared with metabolic (lactate) thresholds, which are limited to the functioning of a single metabolic parameter. The functional thresholds are based on the measurement of mechanical work (i.e., power output) and exercise tolerance and are also readily accessible to coaches and athletes of all levels. The purpose of this study was to examine the association of CP and FTP with cycling time trial performance in a laboratory setting. §Thirteen trained to well-trained MTB riders, including men (n = 8) and women (n = 5), aged between 19 and 51 years, participated in this study. The cycling tests included a ramp incremental test to exhaustion, a 3-min all-out test, a 20-min FTP test, a 20 km (TT2) and 40 km (TT40) time trial. Inferential statistical analysis was done to examine the relationships between CP, FTP, peak power output (PPO), VO2max, TT20 and TT40. Significant correlations were observed between CP, FTP, PPO and VO2max (r = 0.58 to 0.97, p < 0.05), but not between absolute CP and VO2max (r = 0.40, p > 0.05). PPO (338 ± 74 W, 4.7 ± 0.6 W·kg-1), CP (291 ± 78 W, 4.0 ± 0.7 W·kg-1) and FTP (230 ± 63 W, 3.2 ± 0.6 W·kg-1) were significantly correlated to TT20 and TT40 performance times (r = 0.75 to 0.97, p < 0.001). Absolute FTP was more strongly correlated to TT20 and TT40 than CP (r = 0.97 and 0.89 vs. r = 0.75 and 0.78, p < 0.001). Even though the power outputs at FTP and CP were significantly correlated (r = 0.90 to 0.96, p < 0.001), the moderate to low ICC scores (relative: 0.21 and absolute: 0.68), suggests that these two thresholds should not be used interchangeably. The absolute PPO was significantly higher than the power outputs at CP and FTP, while no significant difference was observed between the power outputs at CP and FTP. The relative power outputs were significant different between the power outputs at CP and FTP, but not between PPO and CP. The calculated effect sizes between both relative and absolute measures (ES = 0.61 and 0.38, respectively) suggest that the differences between the power outputs are practically meaningful, even though they were not statistically significantly different. It was concluded that both functional thresholds, CP and FTP (absolute and relative measures), are valid and valuable measures of cycling endurance performance for 20 km and 40 km distances. Of the two thresholds, absolute FTP had the strongest association with cycling time trial performance in a laboratory setting.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Funksionele Draaipunt Krag (FTP) en Kritieke Krag (CP) is beide funksionele draaipunte wat potensieel meer omvattende bepalers is van ‘n atleet se fietsry uithouvermoe-prestasie as metaboliese (laktaat) draaipunte, wat beperk is tot die funksionering van ‘n enkele metaboliese parameter. Die funksionele draaipunte is gebaseer op die meting van meganiese werk (bv. kraguitset) en oefening toleransie en is ook geredelik toeganklik vir afrigters en atlete van alle vlakke. Die doel van hierdie studie was om die voorspellende waarde van FTP en CP op ‘n fietsry tydtoets-prestasie te bepaal binne ‘n laboratorium situasie. Dertien geoefende tot goed-geoefende berg-fietryers, insluitende mans (n=8) en vroue (n=5), tussen die ouderdom van 19 en 51 jaar, het aan hierdie studie deelgeneem. Die fietsry toetse het ‘n inkrementele stap-toets tot vermoeienes, ‘n 3-min maksimale toets, ‘n 20-min FTP toets, ‘n 20 km (TT20) -en 40 km (TT40) tydtoets ingesluit. Betekenisvolle verwantskappe is opgemerk tussen CP, FTP, PPO en VO2max (r = 0.58 tot 0.97, p < 0.05), maar nie tussen absolute CP en VO2max (r = 0.40, p > 0.05) nie. PPO (338 ± 74 W, 4.7 ± 0.6 W·kg-1), CP (291 ± 78 W, 4.0 ± 0.7 W·kg-1) en FTP (230 ± 63 W, 3.2 ± 0.6 W·kg-1) was betekenisvol geassosieer met TT20 and TT40 prestasietye (r = 0.75 tot 0.97, p < 0.001). Absolute FTP het beter gekorreleer met TT20 en TT40 as CP (r = 0.97 en 0.89 vs. r = 0.75 en 0.78, p < 0.001). Al het die kraguitsetwaardes van FTP en CP sterk gekorreleer (r = 0.90 to 0.96, p < 0.001), stel die matig tot lae ICC tellings (relatief: 0.21 en absoluut: 0.68) voor dat hierdie twee draaipunte nie gelykwaardig is nie. Die absolute PPO was betekenisvol hoer as die kraguitset by CP en FTP, terwyl geen betekenisvolle verskil opgemerk is tussen die kraguitsetwaarde by CP en FTP nie. Die relatiewe kraguitsetwaardes was betekenisvol verskillend van die kraguitsetwaardes by CP en FTP, maar nie tussen PPO en CP nie. Die effekgrootte tussen beide relatiewe en absolute metings (ES = 0.61 en 0.38, onderskeidelik) stel voor dat die verskille tussen kraguitsetwaardes prakties betekenisvol is, selfs al was dit nie statisties betekenisvol verskillend nie. Daar is tot die gevolgtrekking gekom dat beide funksionele draaipunte, CP en FTP (absolute en relatiewe afmetings), geldige en betekenisvolle voorspellers is van fietsry uithouvermoe-prestasie oor 20 km en 40 km. Van die twee draaipunte, was absolute FTP die beste voorspeller van ‘n laboratorium-gebaseerde fietsry tydtoets prestasie.af_ZA
dc.description.versionMastersen_ZA
dc.format.extentxiv, 114 pages : illustrationsen_ZA
dc.identifier.urihttp://hdl.handle.net/10019.1/126090
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subjectCycling -- Trainingen_ZA
dc.subjectPlyometricsen_ZA
dc.subjectPlyometric exercisesen_ZA
dc.subjectReactive training (Exercise)en_ZA
dc.subjectCycling -- Physiological aspectsen_ZA
dc.subjectMuscle strengthen_ZA
dc.subjectRespiratory musclesen_ZA
dc.subjectEndurance sports -- Trainingen_ZA
dc.subjectPhysical fitnessen_ZA
dc.subjectExercise -- Physiological aspectsen_ZA
dc.subjectCardiovascular fitnessen_ZA
dc.subjectHeart rate monitoringen_ZA
dc.subjectUCTD
dc.titleFunctional thresholds and its association with 20- and 40 km cycling performanceen_ZA
dc.typeThesisen_ZA
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