<p>GLASS, STEPHEN MICHAEL, Ph.D. Strength, Balance, and Range of Motion as Modifiers of the Effect of External Load-Bearing on Functional Movement Behaviors in the Military Recruitment Population. (2015) Directed by Dr. Scott E. Ross. 172 pp. Clinical movement screens have become increasingly popular in strength and conditioning programs designed for the tactical athlete. Whereas conventionally administered movement screens are largely not sensitive to behaviors which impact soldierrelevant physical performance, recent evidence suggests that modified screens which incorporate external load-bearing strengthen the relationship between movement behaviors and performance outcomes. It remains unclear, however, which mechanisms may account for this improvement in association. Physical performance is considered a multidimensional construct influenced by several independent factors. Among the factors which influence military physical performance, movement screens may require high levels of strength, balance, and range of motion. This project used penalized interaction models to determine the role of strength, balance, and range of motion in modifying the effects of external load bearing on movement quality and movement. Additional confirmatory analyses examined differences in the abilities of FMS item scores to predict physical performance outcomes when those scores were obtained during control vs. external load-bearing conditions. Results suggest that the effect of load on movement complexity is modified by strength, balance, and range of motion whereas the effect on clinically rated movement quality is modified by only balance and range of motion. While the direction of the observed effects did not always coincide with our hypotheses, the present findings mirror those of previous research with respect to differential validity of weighted vs. control FMS item scores in predicting criterion performance measures.

To date, it remains unclear how passive dynamics and active neural control contribute to arm swing during human locomotion. The passive hypothesis attributes arm swing to the passive transfer of energy from the legs to the arms via biomechanical linkages, while the active hypothesis states that arm swing is actively driven by muscles via neural mechanisms. The present study aims to investigate this phenomenon further by disrupting the biomechanical linkages, thereby directly challenging the passive hypothesis. Ten healthy individuals walked on a treadmill with and without an apparatus that constrained pelvis rotation at 3 different speeds (2 mph, 3 mph, and 4 mph). Spatial (upper and lower limb movement amplitudes) and temporal (movement frequencies and phase relationships between segment trajectories) aspects of limb movement were analyzed. The pelvis rotation was reduced by an average of 60.6% while constrained. As the treadmill speed increased, the movement amplitude of the upper and lower limbs increased. While the pelvis was constrained, arm swing amplitude decreased and the muscle activity of the upper limbs and lower limbs was similar to walking in the unconstrained condition. The movement frequency patterns and phase relations between segment trajectories were also conserved irrespective of speed and pelvis constraint conditions. These results provide evidence that passive elements are a significant factor in arm swing amplitude. However, the conserved EMG patterns and movement frequencies are suggestive of an underlying neural drive that contributes to the maintenance of the temporal aspects of gait. These observations are most likely due to passive dynamics in addition to neural mechanisms that maintain the rhythmic locomotor pattern via upper and lower limb central pattern generators (CPGs).

<p> Athletes face a significantly higher risk of developing clinical eating disorders compared to nonathletes (Petrie &amp; Greenleaf, 2007; Sundgot-Borgen &amp; Klugland Torstveit, 2004). One risk factor for the development of eating disorders is body dissatisfaction, which is when an individual has a subjective, negative view of their physical body (Stice &amp; Shaw, 2002). Researchers in the field are calling for future research to examine factors that can be modified and strengthened through targeted interventions. Two such factors are self-efficacy and trait self-control. Self-efficacy is the belief is one&rsquo;s ability to organize the necessary steps to achieve desired goals (Bandura, 1997). Trait self-control is the enduring ability to interrupt undesired behavioral tendencies and resist acting upon them (Baumeister, Vohs &amp; Tice, 2007). The purpose of this study was to examine the relationship between body dissatisfaction, self-efficacy and trait self-control. One hundred and five NCAA division I and division II athletes completed an online questionnaire containing demographic information and measures for body dissatisfaction, self-efficacy and trait self-control. Pearson correlations found a significant positive relationship between trait self-control and self-efficacy. Significant negative relationships were found between body dissatisfaction and trait self-control and body dissatisfaction and self-efficacy. Additionally, two separate one-way ANOVAs were run assessing the effect of sex and division on body dissatisfaction, self-efficacy and trait self-control. Female athletes were found to have higher amounts of body dissatisfaction than male athletes and athletes in division II schools also had more body dissatisfaction than those in division I schools. Future research should examine differences in the sporting environment as well as instrumentation that better satisfies the needs of male and female athletes.</p><p>

<p> Alanine has long been recognized as an important substrate for hepatic gluconeogenesis through the glucose-alanine (Cahill) cycle which plays an important role in the maintenance of euglycemia during times of caloric deficiency. The Cahill cycle involves the transamination of pyruvate by the amino group of glutamate, producing &alpha;-ketoglutarate and alanine. Alanine formed in skeletal muscle during exercise can be sent to the liver where it is used to produce glucose and safely remove the <i>NH</i>₃₊ as urea. This process is catalyzed by the glutamic-pyruvic transaminase (GPT) enzyme, of which two distinct isoforms exist: cytosolic GPT1 and mitochondrial GPT2. However, the precise role of these different enzymes in alanine metabolism remains to be fully elucidated and is an ongoing subject of debate. Likewise, the potential efficacy of exogenous alanine administration as a strategy to improve skeletal muscle glycogen recovery following exercise has not been examined. The following studies were conducted to: 1) evaluate the metabolic effects of L-alanine administration following a bout of exhaustive exercise and 2) determine the role hepatic GPT2 plays in gluconeogenesis from alanine during exercise. </p><p> Administration of L-alanine to C57BL/6 mice kept fasted after an exhaustive bout of exercise did not significantly alter glycogen content in the gastrocnemius during 1 hour of recovery; despite the observation that blood glucose concentrations were elevated at this time compared to mice treated with sterile saline. In addition, treatment with L-alanine resulted in significantly increased blood lactate concentrations at 30 and 60 minutes of recovery. </p><p> Liver specific GPT2&ndash;/&ndash; mice are overtly normal and survive to adulthood with normal exercise tolerance. Gene expression analysis by qPCR reveals LS-GPT2&ndash;/&ndash; mice have higher levels of GPT1 mRNA, which may act to compensate for the loss of GPT2. Indeed, liver specific deletion of GPT2 and the mitochondrial pyruvate carrier 2 (MPC2) resulted in reduced exercise time to exhaustion. Impaired gluconeogenesis was also observed in double knockout mice following 1 hour of recovery from exercise in the fasted state. </p><p> These studies demonstrate that immediately following exercise alanine is not a limiting substrate for skeletal muscle glycogen replenishment or hepatic gluconeogenesis. In addition, we show that loss of GPT2 alone is not sufficient to reduce exercise performance or gluconeogenesis due to compensatory changes in gene expression.</p><p>

abstract: High Intensity Interval Training (HIIT) is a phrase quickly becoming popularized through current research due to the physical and physiological success this method of training has proven to yield in both untrained and trained individuals. There is no set definition used to describe HIIT, but it typically refers to repeated bouts of fairly brief intermittent exercise. A great deal of research outlines the benefits associated with utilizing HIIT in untrained and recreationally trained individuals. However, research on the effect HIIT has or could possibly have on the well-trained endurance athlete is limited, specifically in the sport of rowing. The purpose of this study was to analyze the effect of HIIT on VO2 peak and performance in trained rowers when compared to traditional, endurance training. It was hypothesized that HIIT would be just as effective at improving VO2 peak and performance as the endurance training protocol in well-trained rowers. A total of 20 high school female rowers participated in the study (mean ± SD; age = 16 ± 1). Baseline testing was comprised of a 2000m time-trial test on the Concept IIc Rowing Ergometer and a maximal exercise test, which was also completed on the Concept IIc Ergometer, in order to determine VO2 peak. Subjects were randomly assigned to a HIIT or endurance group for four weeks of intervention. Three days/week the HIIT group completed a 6 by 30second repeated Wingate protocol on the Concept II Ergometer at or above 100% VO2 peak, in which each 30s maximal effort was immediately followed by an active recovery of four-minutes. The endurance group completed 30 minutes of sub-maximal rowing at 65% of VO2 peak three days/week. After four weeks of intervention, post-testing took place, which was identical to baseline testing. Results from this study suggest HIIT was just as effective as endurance training at improving 2k time (mean ± SD; HIIT: 498.7 ± 23.1; Endurance: 497.5 ± 17.6). There were no significant within or between group differences in VO2 peak post-intervention (mean ± SD; HIIT: 44.8 ± 4.0; Endurance: 45.8 ± 5.6). The current study suggests four-weeks of HIIT training can yield similar adaptations in performance when compared to endurance training. / Dissertation/Thesis / M.S. Exercise and Wellness 2011

<p> Over the past decade, there have been many studies (e.g., Pegoraro, Scott, &amp; Burch, 2018) focused on Facebook and the sport industry, but no known research has examined how National Collegiate Athletic Association (NCAA) sports teams employ this social media platform for recruiting purposes. With NCAA social media legislation undergoing an overhaul in 2016, teams and coaches are now enjoying newfound freedoms in communicating with recruits. Therefore, the purpose of this dissertation was to employ a content analysis to examine the social networking practices in Division I women&rsquo;s golf. Using data from 40 programs, the study examined the content and themes of Facebook posts to measure how programs utilized social media to promote themselves and interact with recruits and stakeholders. The study analyzed the usage patterns based on coaching staff demographics and investigated whether the use of ancillary components of programs&rsquo; Facebook posts led to greater engagement. Furthermore, the investigation examined the impact of team rankings on the content posted. In analyzing the multimedia content posted, multiple one-way ANOVA were conducted and revealed that likes, reactions, and comments differed significantly (<i> p</i> &lt; .01) according to post type and post theme. Tukey&rsquo;s HSD test found significant differences between mean number of likes for several post types at the p &lt; 0.05 level. Chi-square analyses yielded significant findings between ranking and post theme (<i>p</i> &lt; .01), between coaching staff members&rsquo; gender and post type (<i> p</i> &lt; .05), and between the age of coaching staff members and post type and post theme (<i>p</i> &lt; .01). Based on these and other findings, recommendations for scholars (e.g., the need for researchers to extend the development of social media study in sport) and practitioners (e.g., the need for coaches to have a more thorough understanding of the trends in social media so they can capitalize on the promotional and interactive opportunities) are provided.</p><p>

<p> Over the last 40 years, a new paradigm has been posited where the variability observed in physiological systems is a consequence of the interactions occurring between the various components that affect the system. While quantifying the magnitude of variability can be useful, analyses that measure how the structure of the variability (dynamics) changes over time have been posited to reflect the health of the system. Many researchers interpret the results of these analyses to be indicative of the system&rsquo;s adaptive capacity. While there is ample indirect evidence to support this notion, a lack of direct findings has left the literature lacking a definitive foundation to move forward with this interpretation. While many physiological systems are too invasive to safely perturb, the movementbased systems are routinely perturbed in real-world environments without dire consequences. Of particular interest is the locomotor system, which is constantly challenged in real-world environments via slips and trips. Furthermore, the locomotor system can be safely and validly perturbed in the laboratory. A range of locomotor dynamics-based measures have been used to describe differences between various clinical populations, but none have been directly associated with a person&rsquo;s ability to remain upright when perturbed. The objectives of this study are to (1) examine the relationship between locomotor dynamics/stability to overall fall-risk prior, (2) examine how locomotor dynamics relate to the ability to recover from a trip via global stability, and (3) determine the extent to which an acute trip-training session alters locomotor dynamics and global stability. Forty healthy, older adults (75.2 &plusmn; 4.9 yrs) were recruited by convenience from the local community. The participants completed a variety of clinical assessments in order to determine overall fall-risk. Afterwards, they participated in three walking trials consisting of: 1) a 15-minute unperturbed walking session, 2) a 10-minute unperturbed walking session (control) or a 10-minute trip-training session (intervention), and 3) a 15-minute unperturbed walking session. Various measurements of locomotor dynamics and adaptability were calculated from full-body 3-D kinematics collected at 100Hz. Multiple regression and repeated measure analysis of variance models were calculated to determine to what extent locomotor dynamics and adaptability relate to one another and how an acute trip-training session affects their relationship. The results from our first experiment suggested that locomotor dynamics and stability during steady state do not significantly relate to overall fall-risk. However, the second experiment showed that locomotor dynamics are predictive of an individual&rsquo;s ability to recover from a trip. Our last experiment showed the feasibility of using an acute trip-training session to alter locomotor dynamics and stability. These data represent the first direct evidence of physiological variability being indicative of adaptive capacity in the locomotor system. Further investigation will be necessary to determine the robustness of the analyses to indicate adaptive capacity across perturbations and populations. </p><p>

<p> This study manipulated common practices variables of contextual interference (CI) and frequencies of augmented feedback in order to determine the optimal practice conditions for beginner and experienced performers of a computer-based task. Twenty participants performed 36 trials in the acquisition of a task that involved moving a computer mouse to click 10 on-screen targets as quickly and accurately as possible. Acquisition trials consisted of either blocked practice with knowledge of results (KR) feedback provided on every trial or random practice with a faded feedback schedule. The extent of learning that occurred was gauged by 24-hour retention and transfer tests of two dependent variables: average response time and average accuracy. In line with the predictions of the <i>challenge point</i> framework, beginner participants demonstrated improved learning through low levels of CI and KR feedback after every trial, while experienced participants benefitted from a high CI and faded KR feedback environment. These findings provide insight about the viability of the challenge point framework and how practice can be structured in distinctive ways to foster skill learning for performers of different skill levels.</p><p>

<p> Older adults are at a high risk for falls and diseases that can be prevented or controlled by achieving the recommended daily amounts of activity as outlined by the U.S. Department of Health and Human Services (2008). Despite this knowledge, older adults continue to be the least active demographic in the United States, not only placing them at higher risk for disease, but increased risk of falls and decreases in quality of life (Bean, Vora, &amp; Frontera, 2004; Nelson, Rejeski, Blair, Duncan &amp; Judge, 2007). The objective for this project was to implement a modified martial arts program for older adults over the age of 60, and determine its impact on physical performance measures and self-efficacy. Testing the working hypothesis that participating in a modified martial arts program increased strength, endurance, balance and self-efficacy of adults over the age of 60 achieved this aim. The approach to testing this hypothesis was to conduct a pre-post intervention study, where participants over the age of 60 were tested on the Sit to Stand, 8-foot Up and Go, Arm Curl, 4-point Balance Scale and Self-efficacy for Exercise Scale (SEE) before and after a 12-week modified martial arts program. The rationale of this research was based on preliminary findings that strongly suggested that martial arts programs have positive effects on participants, but studies had not fully addressed older populations or the modifications needed to make older adult training more effective. New findings in this regard provided further evidence of the effectiveness of a modified martial arts program in increasing the muscle strength, muscle endurance, balance and self-efficacy in adults over the age of 60. This project is significant in that it identified the extent to which martial arts training could be a safe, effective and engaging exercise opportunity, thereby encouraging greater participation in physical activity among older adults. </p><p>

<p> The purpose of this study was to investigate the effect of chains on power characteristics in the hexagonal barbell deadlift. Peak vertical ground reaction force (VGRF), average bar velocity, and peak rate of force development (RFD) were analyzed during four different conditions of various proportions of chains and constant resistance at 60% of each participants&rsquo; 1-repetition maximum (1RM) matched at the top of the lift. The four conditions included 60% of 1RM with no chains (NC), 60% of 1RM with chains accounting for 15% of total load (C15), 60% of 1RM with chains accounting for 30% of total load (C30), and 60% of 1RM with chains accounting for 45% of total load (C45). Ten resistance trained athletes, six males (21.2 &plusmn; 2.3 y, 175.5&plusmn;7.1 cm, 80.8 &plusmn; 11.8 kg) and four females (20.3 &plusmn; 0.5 y, 163.8 &plusmn; 7.6 cm, 75.4 &plusmn; 15.6 kg), volunteered for the study. Significant differences (<i>p</i> &lt; 0.05) in peak VGRF between NC and C30, NC and C45, C15 and C45, and C30 and C45 were found. Significant differences (<i> p</i> &lt; 0.05) in average bar velocity between NC and 30, and NC and C45 were found. No differences were observed in peak RFD. These results suggest that different proportions of chains and traditional resistance can alter force and velocity characteristics during the hexagonal barbell deadlift.</p><p>