EFFECTS OF 60 DAYS OF SIMULATED MICROGRAVITY AND THE INFLUENCE OF JUMP EXERCISE COUNTERMEASURE ON CARDIORESPIRATORY KINETICS

Publikation: Beitrag in Buch/Bericht/KonferenzbandKonferenzbeitrag - Abstract in KonferenzbandForschungBegutachtung

Abstract

IntroductionMuscular oxygen uptake (V’O2musc) kinetics tend to decelerate by long-term exposure to microgravity (Hoffmann et al., 2016). The effects of 6°-head-down-tilt bed rest (HDT), which is commonly used as a long-term microgravity analog, on heart rate (HR) kinetics and V’O2musc have not been reported yet. During long-duration space missions, countermeasures are applied to mitigate microgravity induced adaptations. Kramer et al. (2017) introduced a novel jump exercise countermeasure and evaluated its effects during HDT. The aim of this study was to get insights into HR and V’O2musc kinetics changes to long-term HDT and furthermore the influence of jump exercise countermeasure on these kinetics.
MethodsTwenty-two participants (29 ± 6 years, 181 ± 6 cm, 77 ± 7 kg) were randomly subjected to 60 days of HDT either with (JUMP, n = 11) or without (CTRL, n = 11) almost daily jump exercise in a sledge jump system. Nine days before HDT (BDC-9) as well as two (R+2) and thirteen (R+13) days after HDT subjects performed random work rate (WR) changes (30 W and 80 W) on a cycle ergometer with HR measured beat-to-beat and oxygen uptake breath by breath. V’O2musc was estimated by the approach of Hoffmann et al. (2013) implementing acirculatory model. Kinetics were assessed applying time series analysis by cross-correlating WR with HR or V’O2musc. Higher maxima (CCFmax) of the resulting function imply faster kinetic responses. Mixed-design ANOVA with the factors time and group was calculated to investigate differences.
ResultsCCFmax(HR) was significantly different across the three time points (p < .05). No group effect or an interaction of time and group were found. Post-hoc tests revealed a significant difference in the CTRL group only from BDC-9 to R+2 (0.352 ± 0.028 vs. 0.269 ± 0.019; p < .05) but not for the JUMP group. Neither time nor group effects on CCFmax(V’O2musc) were observed.
DiscussionContrary to observations during long-term microgravity exposition there is no evidence of deceleration of V’O2musc kinetics under these simulated conditions. The difference might be explained by the absence of gravitation in space sojourns and by longer mission durations (153 ± 25 days). HR kinetics were significantly slowed after bed rest deconditioning in the CTRL subjects only. This emphasizes the efficiency of the jump exercise countermeasure in preserving HR kinetics.
ReferencesHoffmann U, Moore AD, Koschate J, Drescher U. (2016). Eur J Appl Physiol, 116(3), 503-11.Hoffmann U, Drescher U, Benson AP, Rossiter HB, Essfeld D. (2013). Eur J Appl Physiol, 113(7), 1745-54.Kramer A, Kuemmel J, Mulder E, Gollhofer A, Frings-Meuthen P, Gruber M. (2017). PLoS ONE, 12(1), 1-18.
OriginalspracheEnglisch
Titel22nd Annual Congress of the EUROPEAN COLLEGE OF SPORT SCIENCE : 5th - 8th July 2017, MetropolisRuhr – Germany BOOK OF ABSTRACTS
Herausgeber*innenA. Ferrauti, P. Platen, E. Grimminger-Seidensticker, T. Jaitner, U. Bartmus, L. Becher, M. De Marées, T. Mühlbauer, A. Schauerte, T. Wiewelhove, E. Tsolakidis
Seitenumfang1
Herausgeber (Verlag)Westdeutscher Universitätsverlag
Erscheinungsdatum07.2017
Seiten114
ISBN (Print)978-3-89966-755-2, 978-3-9818414-0-4, 978-3-89966-777-6, 978-3-89966-776-9
PublikationsstatusVeröffentlicht - 07.2017
VeranstaltungAnnual Congress of the European College of Sport Science - Bochum, Deutschland
Dauer: 05.07.201708.07.2017
Konferenznummer: 22

Fingerprint

Untersuchen Sie die Forschungsthemen von „EFFECTS OF 60 DAYS OF SIMULATED MICROGRAVITY AND THE INFLUENCE OF JUMP EXERCISE COUNTERMEASURE ON CARDIORESPIRATORY KINETICS“. Zusammen bilden sie einen einzigartigen Fingerprint.

Zitation