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Ten well trained cyclists were studied and compared with 12 untrained subjects from a previous study to determine the effects of a high intensity, constant workload bout of cycling on maximum expiratory pressure (Pe_max). Subjects completed a graded exercise test on a Monark cycle ergometer while expired gases were collected to determine maximal oxygen consumption (VO_2max). Subjects then returned on a second day when measurements of each subject's Pe_max, were made prior to riding at the workload corresponding to 90% of their VO_2max until exhaustion. Measurements of expiratory pressure (Pe) were then made immediately post exercise (Pe_IPE), one minute post exercise (Pe_1MIN), three minutes post exercise (Pe_3MIN), and five minutes post exercise (Pe_5MIN). Trained cyclists had a significantly higher Pe_max (x = 116.43 ± 7.76 mmHg) than did untrained subjects (x = 65.75 ± 7.09 mmHg). Also trained cyclists generated a higher absolute Pe throughout recovery than did the untrained subjects. Although expiratory pressure decreased after exercise in both groups, the relative change in Pe over the recovery period, expressed as a percentage of Pe_max, was not different between trained and untrained. Pe_IPE was decreased to 81.87% ± 3.12 of Pe_maxin trained subjects and 82.35% ± 2.85 in untrained subjects (p < .05), recovering somewhat at 1 minute to 89.19% ± 3.59 of Pema, in trained and to 87.74% ± 3.27 in untrained (p < .05) but did not recover to resting levels in either group. Pe_3MIN and Pe_5MIN remained at the same level as Pe_1MIN in both groups. Therefore, a high intensity, short term exercise bout caused expiratory pressure to be decreased in both trained and untrained subjects. / Master of Science

"May 2002." / Bibliography: leaves 123-144. / xiv, 144 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aspects of the control of ventilation and an upper airway dilator muscle (genioglossus) are compared between healthy men and women, in an attempt to identify a gender difference that may contribute to the high male prevalence of sleep apnea. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 2002

Ma Ting. / "July 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 181-196). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Thesis (MSc)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Introduction: Exercise increases skeletal muscle glucose uptake via AMP-activated protein kinase (AMPK) activation and GLUT4 translocation from cytosol to cell membrane. It also promotes glucose utilisation in type 2 diabetic patients via increased insulin sensitivity. Insulin stimulates GLUT4 translocation by activating P13- kinase and protein kinase B (PKB/Akt). We therefore postulated that a connection exists between these two pathways upstream of GLUT4 translocation. Understanding this connection is important in the development of treatment strategies for type 2 diabetes. This exercise-induced increase in AMP-activated protein kinase (AMPK) activation can be mimicked by a pharmacological agent, 5'-aminoimidazole-4- carboxamide ribonucleoside (AlGAR), which is converted intracellularly into 5'- aminoimidazole-4-carboxamide-ribonucleosidephosphate (ZMP), an AMP analogue. Aim: To investigate the effect of two pharmacological AMPK-activating compounds, ZMP and AlGAR, on the phosphorylation of AMPK, the phosphorylation of PKB/Akt as well as possible feedback on insulin-stimulated glucose uptake and GLUT4 translocation. Materials and Methods: Adult ventricular cardiomyocytes were isolated from male Wistar rats by collagenase perfusion and treated with 1 mM AlGAR or 1 mM ZMP in the presence or absence of 100 nM insulin or 100 nM wortmannin, an inhibitor of P13- kinase. Glucose uptake was measured via eH]-2-deoxyglucose (2DG) accumulation. PKB/Akt and AMPK phosphorylation and GLUT4 translocation was detected by Western blotting. Purinergic receptors were blocked with 8-cyclopentyl-1,3- dipropylxanthine (8CPT) and the effect on AMPK phosphorylation noted. Certain results were confinned or refuted by repeating experiments using the isolated rat heart model. Results: AICAR and ZMP promoted AMPK phosphorylation. Neither drug increased glucose uptake but in fact inhibited basal glucose uptake, although GLUT4 translocation from cytosol to membrane occurred. Both compounds also attenuated insulin stimulated glucose uptake. Wortmann in abolished glucose uptake and PKB/Akt phosphorylation elicited by insulin while, in the presence of wortmannin, AICAR and ZMP increased levels of PKB/Akt phosphorylation. Although AICAR and ZMP increased glucose uptake in skeletal muscle, this was not seen in cardiomyocytes. However both compounds increased GLUT4 translocation, clearly demonstrating that translocation and activation of GLUT4 are separate processes. 8CPT had no effect on the phosphorylation of AMPK by either AICAR or ZMP indicating that there was no involvement of the purinergic receptors. Conclusion: Although AICAR and ZMP increase glucose uptake in skeletal muscle, this was not seen in cardiomyocytes. Conversely, both compounds inhibited both basal and insulin stimulated glucose uptake despite increasing GLUT4 translocation. Inhibition of PI3-kinase in presence or absence of insulin unmasked hitherto unknown effects of AICAR and ZMP on PKB phosphorylation. / AFRIKAANSE OPSOMMING: Agtergrond: Oefening verhoog skeletspier glukose opname via AMP-geaktiveerde protein kinase (AMPK) aktivering en GLUT4 translokering vanaf die sitosol na die selmembraan. Dit verbeter ook glukose verbruik in tipe 2 diabetes pasiënte via verhoogde insulien sensitiwiteit. Insulien stimuleer GLUT4 translokering deur P13- kinase en protein kinase B (PKB/Akt) te aktiveer. Dit word dus gepostuleer dat daar 'n verbinding tussen hierdie twee paaie, wat beide betrokke is by GLUT4 translokering, bestaan. Dit is belangrik om hierdie verbinding te verstaan aangesien dit in behandelingstrategieë van tipe 2 diabetes geteiken kan word. Die oefening geïnduseerde verhoging in AMPK aktivering, kan deur 'n farmakologiese middel 5'- aminoimidasool-4-karboksamied ribonukleosied (AICAR), wat intrasellulêr omgesit word na 5'-aminoimidasool-4-karboksamied-ribonukleosiedfosfaat (ZMP), 'n AMP analoog, nageboots word. Doel: Om die effek van twee farmakologiese AMPK-aktiveringsmiddels, AICAR en ZMP, op die fosforilering van AMPK en PKB/Akt, sowel as moontlike effekte daarvan op insulien-gestimuleerde glukose opname en GLUT4 translokering, te ondersoek. Materiale en Metodes: Volwasse ventrikulêre kardiomiosiete is uit manlike Wistar rotharte geïsoleer d.m.v kollagenase perfusies en behandel met 1 mM AICAR of 1 mM ZMP in die teenwoordigheid of afwesigheid van 100 nM insulien of 100 nM wortmannin. Glukose opname is gemeet via intrasellulêre [3H]-2-deoksiglukose akkumulasie; PKB/Akt en AMPK fosforilering sowel as GLUT4 translokering is bepaal deur Western blot analises. Purinergiese reseptore is geblokkeer met 8-siklopentiel- 1,3-dipropielxanthien (8CPT) en die effek daarvan op AMPK fosforilering genoteer. Ten einde resultate wat in die geïsoleerde kardiomiosiet-model verkry is, te bevestig, is sekere eksperimente in die geïsoleerde rothart herhaal. Resultate: Beide AIGAR en ZMP stimuleer AMPK fosforilering. Die middels kan nie glukose opname verhoog nie, inteendeel, basale glukose opname is onderdruk alhoewel GLUT4 translokering vanaf die sitosol na die selmembraan wel plaasgevind het. Wortmannin kon insulien gemedieerde glukose opname en PKB/Akt fosforilering onderdruk. In die teenwoordigheid van wortmannin het beide AIGAR en ZMP PKB/Akt fosforilering verhoog. Alhoewel beide AIGAR en ZMP glukose opname in skeletspier verhoog, was dit nie die geval in kardiomiosiete nie. Beide middels het wel GLUT 4 translokering verhoog, wat duidelik demonstreer dat die translokering en aktivering van GLUT4, verskillende prosesse is. 8GPT het geen effek gehad op die fosforilering van AMPK deur AIGAR of ZMP nie, wat bewys dat daar geen betrokkenheid van die purinergiese reseptore was nie. Gevolgtrekking: Alhoewel AIGAR en ZMP glukose opname in skeletspier verhoog is dit nie die geval in kardiomiosiete nie. Beide middels inhibeer basale en insuliengestimuleerde glukose opname maar stimuleer GLUT4 translokeering. Inhibisie van PI3-kinase in die teenwoordigheid of afwesigheid van insulien, ontmasker voorheen onbekende effekte van AIGAR en ZMP op PKB/Akt fosforilering.

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

The primary focus of this study was to determine basal levels of myogenic (MRF4, myogenin, MyoD), proteolytic (FOXO3A, atrogin-1, MuRF-1), myostatin, and mitochondrial (PGC-1α & Tfam) mRNA in elderly women before and after aerobic training. This approach was taken to gain insight into the molecular adaptations associated with our observed increases in whole muscle cross sectional area (CSA) (11%, p<0.05), knee extensor muscle function (25%, p<0.05) and aerobic capacity (30%, p<0.05) with training. Nine elderly women (71±2y) underwent muscle biopsies obtained from the vastus lateralis before and after 12-weeks of aerobic training on a cycle ergometer. Post training biopsy samples were acquired 48 hours after the last exercise session. Aerobic training reduced (p < 0.05) resting levels of MRF4 by 25% while myogenin showed a trend to decrease (p = 0.09) after training. FOXO3A expression was 27% lower (p < 0.05) while atrogin-1 and MuRF-1 were unaltered after training. Additionally, myostatin gene expression was decreased (p < 0.05) by 57% after training. Lastly, aerobic training did not alter PGC-1α or Tfam mRNA. These findings suggest that aerobic training alters basal transcript levels of growth related genes in skeletal muscle of older women. Further, the reductions in FOXO3A and myostatin indicate the aerobic training induced muscle hypertrophy in older women may be due to alterations in proteolytic machinery. / School of Physical Education, Sport, and Exercise Science

by Wan Yu Kwan. / Thesis submitted in: December 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 112-125). / Abstracts in English and Chinese. / Acknowledgement --- p.2 / Abstract --- p.3 / Table of Contents --- p.5 / Chapter Chapter 1 - --- Introduction --- p.7 / Chapter 1.1 --- Contribution of lifting techniques on risk assessment and training on manual materials handling --- p.7 / Chapter 1.2 --- Objectives --- p.12 / Chapter 1.3 --- Hypotheses --- p.12 / Chapter 1.4 --- Significance of Study --- p.13 / Chapter Chapter 2 - --- Literature Review --- p.14 / Chapter 2.1 --- Societal concerns on employee compensation --- p.14 / Chapter 2.2 --- Etiology of low back injury --- p.15 / Chapter 2.2.1 --- Compression forces on vertebral joints --- p.16 / Chapter 2.2.2 --- Shear forces on vertebral joints --- p.17 / Chapter 2.3 --- Lifting techniques --- p.18 / Chapter 2.3.1 --- Effect of lifting techniques on curvature of the spine --- p.22 / Chapter 2.3.2 --- Importance of leg muscles in manual lifting --- p.22 / Chapter 2.4 --- Prediction of low back injury in manual lifting --- p.24 / Chapter 2.4.1 --- Compression forces and moments --- p.26 / Chapter 2.4.2 --- Balance control --- p.29 / Chapter 2.4.3 --- Application of Surface electromyography in ergonomics --- p.31 / Chapter Chapter 3 - --- Method --- p.34 / Chapter 3.1 --- Subject recruitment --- p.34 / Chapter 3.2 --- Equipment --- p.35 / Chapter 3.2.1 --- Force platform --- p.35 / Chapter 3.2.2 --- Motion analysis system --- p.37 / Chapter 3.2.3 --- Surface electromyography --- p.38 / Chapter 3.3 --- Maximum voluntary contraction test --- p.40 / Chapter 3.3.1 --- MVC of vastus medialis --- p.41 / Chapter 3.3.2 --- MVC of medial gastrocnemius --- p.42 / Chapter 3.3.3 --- MVC of erector spinae --- p.43 / Chapter 3.4 --- Lifting techniques --- p.44 / Chapter 3.5 --- Experimental procedures --- p.48 / Chapter 3.6 --- Statistical analysis --- p.53 / Chapter Chapter 4 - --- Results and Dicussion --- p.54 / Chapter 4.1 --- No. of cases in the study --- p.54 / Chapter 4.2 --- Phases of lifting --- p.55 / Chapter 4.3 --- Process time --- p.56 / Chapter 4.4 --- Trunk inclination angles --- p.62 / Chapter 4.5 --- Hip joint angles --- p.67 / Chapter 4.6 --- Knee joint angles --- p.73 / Chapter 4.7 --- Center of mass of box --- p.79 / Chapter 4.8 --- Muscle activities --- p.84 / Chapter Chapter 5 - --- Conclusion --- p.109 / Chapter Chapter 6 - --- References --- p.112

by Luk tze Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 105-111). / Text in English; abstract also in Chinese. / by Luk tze Chung. / Chapter Chapter One --- Introduction / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Work station design --- p.2 / Chapter 1.3 --- Method of study --- p.4 / Chapter 1.4 --- Purpose of study --- p.5 / Chapter 1.5 --- Variables definition --- p.5 / Chapter 1.6 --- Hypotheses --- p.6 / Chapter 1.7 --- Significance of study --- p.6 / Chapter Chapter Two --- Literature Review / Chapter 2.1 --- Biomechanical study on ergonomics problems --- p.7 / Chapter 2.1.1 --- Ergonomics --- p.7 / Chapter 2.1.2 --- Biomechanics --- p.7 / Chapter 2.1.3 --- Force and torque --- p.8 / Chapter 2.1.3.1 --- Lever systems --- p.8 / Chapter 2.1.3.2 --- Torque and moment --- p.8 / Chapter 2.1.4 --- Biomechanics of the back --- p.9 / Chapter 2.1.5 --- Shoulder biomechanics --- p.10 / Chapter 2.2 --- Manual lifting --- p.12 / Chapter 2.2.1 --- Manual handling and musculoskeletal problems --- p.12 / Chapter 2.2.2 --- Strategies for reducing manual handling injuries --- p.13 / Chapter 2.3 --- Method of analysis in ergonomics problems --- p.13 / Chapter 2.3.1 --- Electromyography --- p.13 / Chapter 2.3.1.1 --- Neurophysiology --- p.13 / Chapter 2.3.1.2 --- Electromyography in biomechanics --- p.14 / Chapter 2.3.2 --- Motion analysis --- p.16 / Chapter 2.3.2.1 --- Direct measurement techniques --- p.16 / Chapter 2.3.2.2 --- Indirect measurement using imaging techniques --- p.17 / Chapter 2.4 --- Summary --- p.18 / Chapter Chapter Three --- Method / Chapter 3.1 --- Subjects --- p.19 / Chapter 3.2 --- Position of EMG electrodes --- p.20 / Chapter 3.3 --- Electromyography (EMG) --- p.23 / Chapter 3.4 --- Normalization of EMG --- p.24 / Chapter 3.5 --- Force platform --- p.31 / Chapter 3.6 --- Motion analysis system --- p.33 / Chapter 3.7 --- Calibration of instrument --- p.39 / Chapter 3.7.1 --- EMG --- p.39 / Chapter 3.7.2 --- Force platform --- p.40 / Chapter 3.7.3 --- Motion analysis system --- p.40 / Chapter 3.7.3.1 --- Calibration of displacement and velocity --- p.40 / Chapter 2.7.3.2 --- Calibration of acceleration --- p.40 / Chapter 3.8 --- Work station design --- p.41 / Chapter 3.9 --- Procedure --- p.42 / Chapter 3.10 --- Data analysis --- p.46 / Chapter Chapter Four --- Results / Chapter 4.1 --- EMG data analysis --- p.47 / Chapter 4.1.1 --- MVC testing results --- p.47 / Chapter 4.1.2 --- Results of ANOVA test --- p.48 / Chapter 4.1.2.1 --- Class level information --- p.48 / Chapter 4.1.2.2 --- ANOVA results --- p.49 / Chapter 4.1.2.3 --- Post Hoc test --- p.53 / Chapter 4.2 --- Motion analysis --- p.63 / Chapter 4.2.1 --- Parameters in motion analysis --- p.63 / Chapter 4.2.2 --- Results of ANOVA test --- p.63 / Chapter 4.2.2.1 --- Post Hoc test --- p.68 / Chapter 4.3 --- Force platform data analysis --- p.84 / Chapter 4.3.1 --- Parameters in force platform data analysis --- p.84 / Chapter 4.3.2 --- Result of ANOVA test --- p.84 / Chapter 4.3.2.1 --- Post Hoc test --- p.85 / Chapter 4.4 --- Results of correlation --- p.89 / Chapter Chapter Five --- Discussion and Conclusions / Chapter 5.1 --- EMG signal --- p.90 / Chapter 5.1.1 --- MVC test --- p.90 / Chapter 5.1.2 --- Results of ANOVA in EMG signal --- p.91 / Chapter 5.1.2.1 --- Cervical erector spinae --- p.91 / Chapter 5.1.2.2 --- Trapezius pars descendens --- p.92 / Chapter 5.1.2.3 --- Infraspinatus --- p.93 / Chapter 5.1.2.4 --- Lumbar erector spinae --- p.94 / Chapter 5.2 --- Motion analysis --- p.95 / Chapter 5.2.1 --- Posture --- p.95 / Chapter 5.2.1.1 --- Absolute thigh angle --- p.96 / Chapter 5.2.1.2 --- Absolute arm angle --- p.96 / Chapter 5.2.1.3 --- Absolute chest and abdomen angle --- p.97 / Chapter 5.2.1.4 --- Absolute neck angle --- p.97 / Chapter 5.2.2 --- Force produced by spinae muscle --- p.98 / Chapter 5.3 --- Ground reaction force analysis --- p.99 / Chapter 5.4 --- Correlation analysis --- p.99 / Chapter 5.5 --- Differences between workers and students --- p.100 / Chapter 5.5.1 --- Muscle activity --- p.100 / Chapter 5.5.2 --- Posture . --- p.100 / Chapter 5.6 --- Conclusions --- p.101 / Chapter 5.7 --- Recommendations --- p.102 / References --- p.105 / Appendix --- p.112