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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effects of water immersion on the recovery and performance of competitive cyclists

Koekemoer, Christa Magrieta 03 1900 (has links)
Thesis (M Sport Sc (Sport Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Post-exercise recovery has become an important area in research due to the high demands placed on competitive athletes. Different recovery strategies are used by athletes during competition and training. For the competitive athlete it is important to maintain performances during competition and also to enhance performances during training. However, if the athlete fails to recovery from daily exhaustive training and competition, inadequate recovery may lead to poor performances, burn-out, sickness and even injuries. There is very little evidence available on the possible performance recovery effects of the use of water immersion during multi days of intensive endurance training. Theoretically, water immersion should aid the overall recovery process without any additional energy cost involved as with active recovery. The objective of this investigation was to determine whether water immersion (cold water vs. neutral) has any effects on the post-exercise recovery rate of competitive cyclists during 3 days of intensive endurance training and whether recovery with water immersion is more effective than active recovery. Seventeen competitive cyclists (mean ± SD age: 27.6 ± 5.94 years, weight: 78.8 ± 6.67 kg, height: 180.5 ± 4.42 cm VO2max: 49.8 ± 4.13 L.min-1.kg-1, and PPO: 352.6 ± 35.94 Watts) completed 3 days of intensive endurance cycling sessions. Cyclists were randomly assigned to either a 20 minute ice bath (IB) (n = 6, 11 ± 0.9oC), neutral bath (NB) (n = 6, 30 ± 0.6oC), or active recovery (AR) (n = 5; 81 ± 1.74% of HRLT ) which were performed directly after the training sessions on Day 1 and 2. Dependent variables such as anaerobic performance, creatine kinase concentrations (CK), c-reactive protein concentrations (CRP), blood lactate concentrations, muscle soreness (VAS) and perceived fatigue (POMS), and limb circumferences were measured prior to the training sessions at Day 1, 2 and 3. In addition, changes in exercise performances over the last 2 days were also assessed. There were significant increases over the three days in plasma [CK] (P < 0.05) and [CRP] (P < 0.001) demonstrating that muscle damage and inflammation occurred during and after the training sessions. However, there were no treatment or interaction effects observed for any of the dependent variables for any of the recovery interventions (P > 0.05). Blood [La] was significantly reduced on Day 2 for the IB group in comparison to the NB group (P < 0.05). A strong tendency was observed for [CK] when the IB and NB groups were combined (WG), indicating that AR had a strong tendency to enhance the recovery of [CK] in comparison to the WG (P = 0.05). Also, there were no significant time or interaction effects observed in % changes in performances for the last two 100km TTs between Day 2 and 3 for any of the recovery interventions (P > 0.05). These findings suggest that neither cold water, nor neutral water therapy, have more beneficial effects on post-exercise recovery rates compared to active recovery. Importantly, however, is that the cyclists’ were able to maintain their performances over the three consecutive days, indicating that water therapy per se is not detrimental to endurance performance. / AFRIKAANSE OPSOMMING: Na-oefening herstel het ‘n belangrike area van navorsing geword, aangesien die eise wat aan elite atlete gestel word buitengewoon hoog is. Vir die kompeterende fietsryer is dit baie belangrik om prestasie tydens kompetitisie asook tydens inoefening te handhaaf. Inteendeel, as die atleet nie daarin slaag om effektief te herstel na daaglikse oefening en kompetisie nie, mag dit lei tot swak prestasie, uitbranding, siekte en beserings. Tot hede is daar geen baie min bewyse beskikbaar oor die potensiële voordele van waterterapie vir die herstel van atlete, veral tydens meervoudige dae van intensiewe uithouvermoë inoefening. Teoreties behoort waterterapie die algehele herstelproses bevorder sonder dat enige addisionele energiekostes betrokke is, soos in die geval van aktiewe herstel. Die doel van die ondersoek was om vas te stel of waterterapie (koud teenoor neutraal) enige effekte het op die na-oefening hersteltempo van kompeterende fietsryers tydens 3 dae van intensiewe uithouvermo oefening en om te bepaal of waterterapie meer effektief is as aktiewe herstel. Sewentien kompeterende fietsryers (gemiddeld ± SD; ouderdom: 27.6 ± 5.94 jaar, gewig: 78.8 ± 6.67 kg, lengte: 180.5 ± 4.42 cm, VO2maks: 49.8 ± 4.13 L.min-1.kg-1, en Piek krag uitset: 352.6 ± 35.94 Watts) het 3 dae van intensiewe uithouvermoë inoefeing voltooi. Die fietryers was lukraak ingedeel in ‘n 20 minute Ysbadgroep (IB) (n = 6, 11 ± 0.9oC), neutrale bad groep (NB) (n = 6, 30 ± 0.6oC) en ‘n aktiewe herstelgroep (AR) (n = 5; 81 ± 1.74% van HRLT), Herstelsessies het op Dag 1 en 2 direk na die inoefeningsessies plaasgevind. Afhanklike veranderlikes soos funksionele kapasiteit, kreatienkinase konsentrasies (CK), c-reaktiewe proteïen konsentrasies (CRP), bloedlaktaat konsentrasie ([La]), spierseerheid en persepsie van vermoeienis (STEMS), en beenomtrekke was gemeet voor die inoefeningsessies op Dag 1, 2 en 3. Veranderinge in oefeningprestasie oor die laaste 2 dae was ook geassesseer. Daar was ‘n statistiese betekenisvolle toename in plasma [CK] (P < 0.05) en [CRP] (P < 0.001) oor die drie dae, wat daarop wys dat spierskade en inflammasie wel plaasgevind het. Daar was geen behandeling of interaksie effekte waarneembaar vir enige van die intervensies nie (P > 0.05). Bloed [La] was beduidend verlaag op Dag 2 vir die IB groep in vergelyking met die NB groep (P = 0.05). Die verlaging in plasma [CK] na AR het gegrens aan statisties betekenisvolle resultate (P = 0.05) in vergelyking met die waterterapie (IB en NB gekombineer). Daar was geen statisites beduidende tyd of interaksie effekte waargeneem in die % veranderinge in oefeningprestasie vir die laaste twee 100km tydtoetse tussen Dag 2 en 3 vir enige van die herstelstrategieë nie (P < 0.05) Die resultate wys dat waterterapie nie enige voordelige effekte op die na-inoefening herstel tempo het in vergelyking met aktiewe herstel nie. Dit is egter belangrik om daarop te let dat die fietsryers in staat was om hul oefeningprestasies te handhaaf oor die drie opeenvolgende dae, wat aandui dat waterterapie nie nadelig inwerk op uithouvermoë prestasie nie.
2

Fiziološki aspekti otpornosti hrasta lužnjaka (Quercus robur L.), cera (Quercus cerris L.) i crne topole (Populus nigra L.) u uslovima vodnog deficita / Physiological aspects of resistance of common oak (Quercus robur L.), the Turkey oak (Quercus cerris L.) and black poplar (Populus nigra L.) under conditions of water deficit

Topić Mirjana 29 September 2015 (has links)
<p>&nbsp; &nbsp; U radu je ispitan uticaj vodnog deficita na fiziolo&scaron;ke osobine klonova crne topole i<br />populacija hrasta lužnjaka i cera, kao i mogućnost oporavka ovih biljaka nakon ponovnog uspostavljanja optimalnog vodnog režima. Cilj istraživanja je bio da se ukaže na potencijal ispitivanih genotipova topole i hrastova za opstanak u&nbsp; promenljivim uslovima životne sredine, u skladu sa aktuelnim klimatskim promenama koje uključuju smanjenje količine padavina i ograničenu dostupnost vode. Dobijeni rezultati su pokazali specifično variranje ispitivanih morfo-anatomskih, fiziolo&scaron;kih i biohemijskih parametara koje je zavisilo od momentalne vlažnosti zemlji&scaron;ta na primenjenom tretmanu (kontrola, su&scaron;a praćena oporavkom, konstantna su&scaron;a) i od genotipa biljke.<br />&nbsp; &nbsp; Negativan uticaj vodnog&nbsp; deficita na tretmanu konstantne su&scaron;e je u najmanjoj meri bio ispoljen na rastenje klona topole X/32, populaciju hrasta lužnjaka L1 i populaciju hrasta cera C1. Indeks tolerancije na stres izračunat na osnovu visine biljke (PHSI) takodje je potvrdio dobru morfolo&scaron;ku prilagodjenost pomenutih genotipova<br />na uslove su&scaron;e. Dobijene vrednosti indeksa stoma ukazuju da vodni status ispitivanih populacija hrastova nije bio naroĉito pogodjen vodnim deficitom na su&scaron;nim tretmanima.<br />&nbsp; &nbsp; Tretman konstantne su&scaron;e je u oba ogleda&nbsp; doveo do najvećeg smanjenja vrednosti<br />parametara razmene gasova kod skoro svih genotipova. S druge strane, primenjeni su&scaron;ni tretmani nisu uslovili smanjenje sadržaja fotosintetiĉkih pigmenata, kao ni parametra Fv/Fm, kod većine ispitivanih biljaka. U odnosu na kontrolu, sadržaj prolina u listovima ispitivanih biljaka na tretmanu konstantne su&scaron;e bio je&nbsp;&nbsp;&nbsp; znaĉajno povećan, a aktivnost enzima nitrat-reduktaze značajno smanjena, kod većine genotipova.<br />&nbsp; &nbsp; Genotipovi kod kojih u uslovima jakog vodnog deficita nije do&scaron;lo do značajne promene većine ispitivanih morfo-anatomskih, fiziolo&scaron;kih i biohemijskih parametara mogu biti od velike važnosti kad je u pitanju njihov odabir i upotreba za uspe&scaron;no po&scaron;umljavanje su&scaron;nih stani&scaron;ta, kojih će biti sve vi&scaron;e usled negativnog uticaja brojnih ekolo&scaron;kih činilaca nastalih kao posledica klimatskih promena.</p> / <p>The impact of water deficit and recovery on physiological features of the black poplar clones, as well as of the oaks populations were analyzed. The aim of this research was to indicate the potential of the studied genotypes for survival under changing environmental conditions, in accordance with current climate changes, which include the reduction in amount of rainfall and limited water availability. Obtained results have shown a specific variation of studied morpho-anatomical, physiological and biochemical parameters which depended on soil humidity on the applied treatment (control, drought followed by recovery and permanent drought), as well as on plant genotype.</p><p>Water deficit on permanent drought treatment had little negative effect on plant growth of poplar clone X/32, as well as oak populations L1 and C1. Plant height stress tolerance index also confirmed good morphological adaptation to drought of these genotypes. Stomatal index was not negatively affected by water deficit in oak plants.&nbsp;&nbsp;&nbsp;&nbsp; In both experiments, a permanent drought treatment led to the largest reduction in the values of gas exchange parameters in almost all genotypes.</p><p>On the other hand, concentration of&nbsp; photosynthetic pigments was not considerably decreased in plants exposed to water deficit, as well as the parameter Fv/Fm, in most examined plants. Compared to the control, the impact of permanent drought treatment&nbsp; on biochemical parameters was expected, in the most cases.&nbsp;&nbsp;&nbsp;&nbsp; Compared to the control, proline content in leaves of most examined genotypes was significantly increased on permanent drought treatment, while nitrate reductase activity was significantly decreased.</p><p>Examined genotypes exhibiting slight or no reduction in values of the most&nbsp; examined parameters during severe&nbsp; drought stress, could be used for afforestation in arid sites. Arid habitats appeared to be more numerous due to the effects of global climate changes.</p>

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