Thesis (MApSc(HumanMovement))--University of South Australia, 2002.

Thesis (M.S. in human nutrition)--Washington State University, August 2009. / Title from PDF title page (viewed on Aug. 12, 2009). "School of Food Science." Includes bibliographical references (p. 73-93).

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2002. / Includes bibliographical references (leaves 28-32).

Thesis (Ph. D.)--University of Connecticut, 2005. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph. D.)--University of Connecticut, 2006. / Title on fiche header: Effects of endurance exercise on skeletal muscle protein turnover and intracellular signaling. Includes bibliographical references.

Extreme physical exertion is commonly associated with acute physiological changes in immune variables known to disturb host defences. Likely induced by the production of stress hormones (e.g., cortisol), partaking in ultra-endurance events with accompanying physiological stressors (e.g., environmental extremes, sleep deprivation and compromised hydration and (or) nutritional status) may amplify stress hormone responses and compromise immune status to a greater extent. To date, research investigating the impact of extreme physical exertion (e.g., ultra-marathon events) on physiological variables is extremely limited. More recently, the potential use of probiotics with known immunomodulatory effects may be considered an appropriate nutritional strategy to improve host defences and minimise and (or) prevent sub-clinical or clinically significant outcomes in active populations.

Glycine-arginine-alpha-ketoisocaporic acid calcium (GAKIC) is a product advertised to increase muscular endurance during exercise via metabolic intervention. Purpose: The purpose of this study was to determine the effect of GAKIC ingestion on maximum strength and muscular endurance. Methods: Utilizing a double-blinded, crossover design, participants completed an upper and lower body resistance exercise protocol once using 11.2gs GAKIC, and the other with a placebo. Results: An increase in maximum strength was observed in the 1RM portion of the lower body protocol phase with statistical trends in the lower body TLV portion of testing. No significant differences were found in upper body 1RM, upper body TLV, HR, BLa, and Glucose between conditions. Conclusion: We concluded that in this protocol, GAKIC increased maximum strength in the 1RM leg press exercise. Further research is encouraged in resistance exercise.

Ergogenic L-citrulline and malate are amino acids used in specific combination to effect muscular endurance during athletic performances. Purpose: The study aimed to investigate the ergogenic properties of citrulline-malate (CM) during a resistance training protocol. Methods: Utilizing a randomized, counterbalanced, double blind study, fifteen trained males completed a resistance training protocol once using placebo (PL) and once with CM (8.0g). Results: CM supplementation increased repetitions in chin-ups, reverse chin-ups, push-ups, and total trial repetitions. Blood lactate was significantly increased post-exercise compared to pre-exercise, but was not significantly different between CM and placebo. Further, a significant interaction effect was revealed for systolic blood pressure, a significant condition effect for diastolic blood pressure, and a significant time effect for HR. Post-hoc analysis revealed that SBP responses were more elevated in the placebo condition during recovery. Conclusion: Collectively, these novel findings suggest CM increases muscular endurance during upper body resistance exercise.

<P> The limited strength model of self-regulation describes self-regulation as a limited, consumable, and renewable internal resource that is depleted when people attempt to control their emotions, thoughts or behaviours (Baumeister & colleagues 1994; 1996). Evidence indicates a consistent relationship across emotional, mental, and physical domains that task performance in all of these areas draws on the same limited resource and is governed by processes occurring within the central nervous system (Galliot, et al., 2007). The main purpose of this study was to examine the effects of self-regulation depletion on muscle activity (EMG) and physical stamina via an isometric task (ankle dorsiflexion). A secondary objective was to investigate trait self-control as an effect modifier of cognitive self-regulation depletion effects on physical stamina. It was hypothesized that individuals would show a greater decline in isometric endurance performance after undergoing a self-regulatory depletion manipulation compared to when they were exposed to· a non-depletion task of similar duration. It was also expected that participants would exhibit greater increases in EMG amplitude after being depleted compared to when not depleted. Additionally, it was hypothesized that people who scored lower on a measure of trait self-control would demonstrate greater depletion effects (i.e., greater pre-to-post performance differences) than those who scored higher on trait self-control. The study was a within-subjects cross-over design involving 31 informed and consenting sedentary university students (M^age= 21.72 ± 2.57 years). Participants were stratified by gender and randomized to experience either cognitive depletion (modified Stroop task) or non-depletion (colour word reading task) for their first trial. In each trial, they completed two isometric ankle dorsiflexion endurance trials at 50% of their MVC (predetermined by initial MVC) separated by the cognitive task. Due to an unexpected differential carryover effect of exposure order, analysis of the data was carried out for each testing session, with primary analysis focused on Time 1 as suggested by Grizzle (1965). Time 1 data indicated a trend towards significance (p = .13) for performance declines being greater in the depletion group compared to the non-depletion group, and a small effect size of .27 was detected, which is comparable to findings in other related studies (Bray et al., 2008; Muraven & Shmueli, 2006). No statistically significant differences emerged for muscle activity in the tibialis anterior for the depletion group compared to the non-depletion group. Those individuals who scored lower on trait self-regulation showed a non-significant trend towards greater depletion effects on muscular endurance performance than those who scored higher on trait self-regulation (p = .13; Cohen's d = .32). Results support the limited strength model of self-regulation and the trait self-control as an·individual difference factor affecting self-regulation, but raise questions regarding the role of central fatigue effects on muscular activation following self-regulatory depletion. </p> / Thesis / Master of Science (MSc)

Work-related musculoskeletal disorders (WMSDs), particularly overexertion injuries, represent a significant economic burden and involve substantial adverse personal outcomes. Two important contemporary changes in workforce demographics may be associated with an increase in the future incidence and cost of WMSDs. First, more than two-thirds of the US adult population is now either overweight or obese, a doubling of the prevalence of obesity over the past 30 years. Second, there has been a shift toward an older worker population, whose injuries often require more time away from work. Obesity and aging can modify job demands and affect worker capacity in terms of muscular and psychomotor function. However, there is a lack of empirical studies quantifying the work-relevant (or ergonomic) impacts related to task demands, capacities, and their potential imbalance. This research assessed obesity- and age-related differences in physical capacity by measuring localized muscle fatigue, endurance, and the effects of fatigue on psychomotor function. Three experiments were completed, progressing from controlled static to more complex intermittent and functional tasks. The work also examined whether obesity and age effects are modified by workplace/workstation configuration, specifically the extent to which body segment masses need to be supported. With obesity, strength was higher, but endurance time was lower, particularly for the more complex tasks. Interaction effects between obesity and age were seen in only a few measures across the studies and did not indicate a consistent effect. Outcomes of this research can facilitate the development of more effective (i.e., inclusive) guidelines to control WMSD risk and contribute to both proactive and reactive interventions to reduce excessive exposures to physical risk factors. Overall, the research goal is to help ensure that ergonomic guidelines and practice are appropriate (or are adapted) to accommodate the diverse and changing workforce. / Ph. D.