The purpose of this study was to examine the effects of acute aerobic exercise on cardiovascular reactivity to psychological stress. Twenty-four trained male cyclists (aged 19-26) from local cycling teams and clubs in the Blacksburg, Virginia area participated in this exercise study. These subjects cycled a minimum of 4 times per week, 30 minutes per session and were randomly assigned to either the Cold Pressor (CP) or Stroop Color Word (SCW) tasks. All subjects participated in exercise and control sessions. The exercise session consisted of 30 minutes at 70% VO₂ max and the control session involved several health assessments with no exercise. There was no significant difference in blood pressure (BP) or heart rate (HR) change scores (peak-baseline) for treatment or interaction effects. Baseline and recovery systolic blood pressure (SBP), however, showed significant differences for the main effect of treatment (exercise vs. control) (p<.05); interaction effects had a tendency toward significance (p=.09) for baseline SBP. These differences in baseline prompted a re-analysis to statistically explore a possible reduction in anticipatory response to psychological stressors. No treatment or interaction effects were found in this secondary analysis. The results of this study provide only limited support for the hypothesis that acute aerobic exercise reduces BP response to subsequent non-exercise stressors. The effects, if present at all, appear to be stronger in the baseline or anticipatory period. Future research designs should be capable of specifically examining effects in the anticipatory period. These results also provide little support for a selective effect of aerobic exercise on BP reactivity based upon the type of stressor presented. / Master of Science

Indian club swinging (ICS) is a training modality that has a rich history across the world (Simpson & Jalli, 2009). Countless practitioners of ICS have praised the physiological benefits they have received from ICS, but there remains a paucity in the objective literature demonstrating these benefits. This dissertation aimed to assess and better understand the physiological and performance changes experienced by an individual participating in an acute bout of repetitive and submaximal upper extremity exercise with Indian clubs (ICs). Chapter 3 examined the impact of an 8-minute bout of ICS by objectively assessing the joint mobility and musculoskeletal performance of individuals after performing the ICS routine. The results showed that isokinetic peak torque and relative peak torque at 60°∙sec-1 during the D2 diagonal pattern away from the body were significantly greater in the IC condition when compared with the control. Also examined was the feasibility of using eight 1-hour practice sessions with novice club swingers to develop ICS competency to perform 8 minutes of continuous swinging. The results demonstrated that this amount of practice would be adequate to teach novice club swingers the appropriate form/technique to complete the ICS routine safely. Chapter 4 compared active shoulder mobility and isokinetic strength, endurance, and power in participants after a standardized dynamic warm-up routine for the upper extremity, consisting of repetitive, low-intensity, large range of motion movements under three separate conditions (holding 2lb ICs, 2lb dumbbells, or no external load). The results showed that internal rotation of the glenohumeral joint improved in active range of motion in the IC condition and was significantly greater than both the dumbbell and no external load groups. Peak torque and total work during isokinetic shoulder flexion at 60°∙sec-1 was significantly greater for IC compared with the dumbbell condition but not the no external load condition, and total work during isokinetic shoulder internal rotation at 180°∙sec-1 was significantly greater for IC compared with the dumbbell condition but not the no external load condition. Self-reported perceived experiences of participants after each condition were also examined in this chapter. The results showed that participants felt more warmed-up and more fatigued after the IC and dumbbell condition compared with the no external load condition. High enjoyment values were reported for all three warm-up conditions. Chapter 5 compared shoulder internal rotation range of motion and girdle stability between exercise conditions (IC and no external load) measured before and after a standardized warm-up. The results showed active internal rotation improved after the IC condition compared to the no external load condition, and the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) scores improved after participants performed either the IC or the no external load warm-up. Participants’ perceived exertion increased significantly after performing either the IC or the no external load warm-up, but they reported significantly higher perceived exertion after performing the IC warm-up compared with no external load. Participants’ affective responses were lower after performing the IC condition compared with the no external load condition but were not significantly different between rested and warmed-up ratings in either condition. In conclusion, performing a warm-up with ICs can result in improved strength, endurance, power, stability and mobility in the upper extremity. It will also increase the intensity and perceived exertion of the warm-up but does not diminish the enjoyment and affective response the participant experiences. Additionally, individuals do not have to perform traditional ICS exercises to experience the positive benefits of using ICs as a tool to enhance their warm-up. Using a regressed version of traditional ICS patterns that are easier to perform is an acceptable and effective way to incorporate Indian clubs into the warm-up phase of an exercise session.

Female athletes exhibit three- to six-fold greater incidence of noncontact anterior cruciate ligament (ACL) injury relative to their male counterparts. The increased risk appears to stem from interactions between several risk factors, that can roughly be categorized as anatomic, biomechanical, hormonal, and neuromuscular. Neuromuscular risk factors have recently gained a greater focus, and include differences in the timing and magnitude of activation of lower extremity and trunk musculature. In addition to neuromuscular risk factors, the incidence of ACL injury is not evenly distributed across the menstrual cycle, suggesting that hormonal fluctuations may influence neuromuscular control. Finally, it is known that even well-trained athletes experience decrements in performance and postural control when forced to attend to multiple sensory stimuli, which is common in many sports. PURPOSE: To explore neuromuscular differences in the ways healthy and ACL-injured women respond to a secondary task requiring fine motor control and sustained mental focus (typing task). Our investigation encompassed three broad aims. First, we sought to determine whether ACL-injured individuals demonstrated similar reflex profiles to healthy individuals, as well as to determine whether the ACL-involved limb was similar to its uninvolved counterpart. Our second aim was to determine whether the typing task resulted in attenuated Hoffmann (H) reflex amplitudes, and to investigate whether any observed changes were similar in healthy and ACL-injured groups. Finally, our third broad aim was to utilize more complex H reflex analysis techniques to determine whether differences in spinal excitability existed at different points in the menstrual cycle. METHODS: Thirty nine recreationally active women (20 with prior unilateral noncontact ACL injury: 24.0 ± 4.5 years; 23.8 ± 4.5 kg•m⁻²; 4.1 ± 2.6 years post-injury; 19 with no history of knee injury: 23.8 ± 4.5 years; 23.1 ± 2.3 kg•m⁻²) agreed to participate, and were tested during days 2-5 (follicular phase) of the menstrual cycle. A sub-set of this original group (n=8; 24.0 ± 4.8 years; 22.0 ± 2.1 kg•m⁻²) also agreed to return for a second testing session 24-96 hours after ovulation (early luteal phase), in order to assess H reflex differences across the menstrual cycle. During each testing session, H reflex testing was used to explore spinal-level control mechanisms of the lower extremity musculature under both Rest and Task conditions. In the control group, the dominant limb was tested (CON-D) while in the ACL group, both the uninvolved (ACL-UN) and involved (ACL-INV) limbs were assessed. Differences between groups (Control vs. ACL) and within-groups (ACL-UN vs. ACL-INV) were explored. RESULTS: At rest, H reflex parameters in ACL-INV were generally similar to ACL-UN and to CON-D. However, differences in presynaptic inhibition were apparent in ACL-INV that imply reduced reflex plasticity. During the typing task, both the Control and ACL groups experienced attenuated H reflex parameters. In the sub-set of participants who were tested twice during the menstrual cycle, a significant increase in presynaptic inhibition was observed during the early luteal phase compared to the follicular phase. CONCLUSION: While individuals with prior ACL injury display similar H reflex profiles to healthy individuals, the ACL-involved limb may demonstrate less reflex plasticity in response to environmental changes. This lack of plasticity may potentially increase the risk of re-injury. In addition, an upper extremity task requiring fine motor control and sustained mental focus attenuates the H reflex in both groups. This attenuation has implications for lower-extremity neuromuscular control in dual-task environments. Finally, the increase in presynaptic inhibition observed during the early luteal phase may provide insight into why ACL injuries are not evenly distributed across the menstrual cycle. / Graduation date: 2012

Clothing is the primary means that wilderness backpackers have to protect themselves from injuries and illnesses that can occur while hiking in the cold. The current method of layering clothing may not meet backpackers' needs for both thermal insulation and heat dissipation, particularly in areas of the body that produce greater sweat, and during times of high physical exertion. No previous studies have addressed backpackers' needs for thermal and moisture comfort in different body areas within a single layer garment. The purpose of this study was to design and evaluate a single-layer garment of different textiles, to improve the physiological comfort of male backpackers hiking in cold winter weather conditions. The objectives of this study were to identify the physiological comfort needs of male backpackers hiking in the cold, to design a prototype backpacking shirt to improve comfort, and to evaluate the comfort and performance of the prototype over time, in comparison to a control. Male backpackers were recruited from a wilderness therapy company in Bend, Oregon, where subjects' employment duties included regularly backpacking in the cold. Qualitative data was collected by interviewing the subjects about their physiological comfort needs, types of garments and materials worn, dissatisfactions and preferences with hiking clothing, and locations on the body that need better attention to thermal and moisture comfort. Information provided by the qualitative interviews was used to develop design criteria. From the guarded hot plate and moisture management testing, results were used to select one thermal insulation, moisture management, and control fabric for the garment design. Based on the design criteria, a prototype shirt was developed. A prototype garment was constructed using the combination of the thermal, moisture, and control fabrics; while a control garment was constructed in an identical style using only the control fabric. The prototype and control garments were worn and tested by subjects while they backpacked. Additionally, comparisons of thermal insulation data between the prototype and control garment were collected on a thermal manikin. Major findings from the qualitative interviews were that subjects preferred base layer shirts made with synthetic fibers and style features that helped retain body heat. Subjects preferred to have greater thermal insulation in the chest and the arms, and less thermal insulation in the underarms and upper back area. Additionally, subjects were concerned about durability. A polyester fleece pile-knit was selected for the thermal insulation fabric and located in the arms and chest of the prototype. The moisture management fabric selected was a polyester fiber mesh knit fabric and was located in the upper back, underarms, and side seams of the garment. The control fabric was a brushed polyester double knit fabric and was located in all other body areas of the prototype and in the entire control garment. The wear test data indicated that both the control and prototype garments were perceived to be comfortable. The prototype had slightly better overall comfort than the control, and there were significant differences found between the prototype and the control in the areas of overall comfort, combined thermal comfort, and combined moisture comfort. The prototype did not consistently have better comfort performance than the control in each trial and for each subject. It was found that the prototype and control shirts could be worn without additional layers when the temperatures were above 35 ��F and 40 ��F, respectively. Thermal manikin testing results confirmed that the overall thermal insulation of both test shirts was equal, but that the prototype had greater or less thermal insulation than the control in specific body areas, depending on the placement of the thermal insulation or moisture management fabric. In summary, the prototype shirt designed in this study has accomplished the goal of providing backpackers' physiological comfort needs identified in the qualitative interviews.�� The design prototype, when worn alone, is able to keep backpackers comfortable when hiking in cold conditions, particularly in temperatures above 35��F. Although not intended to be worn as part of a layer system, the prototype also keeps backpackers comfortable when they are wearing multiple clothing layers. The use of different fabrics in different body areas satisfies the backpackers' needs of both retaining and dissipating body heat with changes in physical activity. Although both the prototype and the control shirts were found to have good thermal, moisture, and overall comfort, the prototype had slightly higher overall comfort ratings than the control.�� In addition, both the prototype and the control were perceived to be better than the subjects' own base layer shirts, and all subjects were willing to recommend the shirts to other hikers. / Graduation date: 2013

The differential role that airborne particulate matter (PM) size fractions, sources, and components play in producing adverse health effects is not fully understood. Specific gaps include the role of PM generated by traffic and the effects of PMs generated by natural sources. Source specific air pollution epidemiological research still lacks integration in the risk assessment process, a fundamental tool to inform policy makers and the public about the current situation or the impact of future or past air pollution policies. This thesis addresses both these gaps. To explore the effects of PM from different sources, we investigated the association between different PM size fractions and mortality in Barcelona, Spain and used PM chemical composition data to help determine the different sources and components linked to toxicity. To illustrate that local air pollution risk assessments are useful tools in evidence-based public health, we estimated the health and economic benefits that would result from different scenario of improved air quality in the Barcelona metropolitan area and in two communities of Southern California. These case studies include new methods to integrate into the risk assessment process the recent epidemiological evidence related to the effects of traffic exposure.This thesis contributes to a better understanding of the link between particulate matter size fraction, sources, and components and health effects, and to improve air pollution health impact assessment methods. Both contributions have important implications for public health and air pollution public policy. / El papel diferencial en que las diferentes fracciones de partículas en suspensión en el aire (PMs), sus fuentes y componentes producen efectos adversos para la salud no está completamente entendido. Las lagunas actuales incluyen el papel de las PMs generadas por el tráfico y los efectos de las PMs generadas por fuentes naturales. La investigación epidemiológica relacionada con fuentes todavía falta ser integrada en el proceso de evaluación de impacto, una herramienta fundamental para informar a los tomadores de decisiones y el público sobre la situación actual o el impacto de futuras o pasadas políticas de contaminación atmosférica. Esta tesis trata estas áreas. Para explorar el papel de las PMs generadas por diferentes fuentes, se ha investigado la asociación entre diferentes fracciones de PMs y mortalidad en Barcelona (España) y se ha usado datos de composición química de PMs para identificar las fuentes y los componentes relacionados con la toxicidad. Para ilustrar que las evaluaciones de impacto a nivel local son herramientas útiles en salud pública, se ha estimado el beneficio en salud y económico que resultaría de diferentes escenarios de mejora de la calidad del aire en el área metropolitana de Barcelona y en dos comunidades de California del Sur. Estos estudios de casos incluyen nuevos métodos para integrar en las evaluaciones de impacto las nuevas evidencias epidemiológicas que relacionan la exposición al tráfico con los efectos en salud. Esta tesis contribuye a un mayor entendimiento del vínculo entre las fracciones de PM, sus fuentes y componentes y los efectos en salud así como a la mejora de los métodos de las evaluaciones de impacto. Estas contribuciones tienen importantes implicaciones para la salud pública y las políticas públicas de contaminación atmosférica.

Caffeine is the most widely consumed socially acceptable drug in the world and is commonly used for its ergogenic properties with demonstrated performance enhancing effects in endurance, power and strength based activities. Despite a wealth of evidence concluding a caffeine induced performance benefit, the direct effects of the drug on peripheral physiological processes have not been fully examined. Early works showed high dose caffeine has direct force potentiating effect on skeletal muscle, a notion that has only recently been confirmed by James et al. (2005) to also occur at a maximal human physiological concentration (70µM). The present research, using mouse muscle as a model for mammalian muscle in general, provides an in-depth assessment of the direct effect of physiological concentrations of caffeine on isolated skeletal muscle performance. This research uniquely: quantifies the dose response relationship; assesses the effects of caffeine on maximal and sub maximal muscle power output and fatigue; looks at the relationship between muscles with different fiber type compositions. As high concentrations of caffeine and taurine are a constituent of many energy drinks, the suggested interaction of these ingredients to further potentiate muscle mechanical performance was also assessed. The study further examines how mammalian muscle mechanical properties change over an age range of development to aged, and how this differs between muscles with predominantly different anatomical locations and functions. In light of this the age related direct effect of physiological concentrations of caffeine was assessed in order to examine whether the ergogenic benefit changed with age. The present results demonstrate a direct muscle performance enhancing effect of physiological concentrations of caffeine that is likely to promote greater benefit on long duration endurance based activities. Furthermore, the present study demonstrates that there is no direct effect of physiological concentrations of taurine and no further performance enhancing benefit when combined with caffeine. Finally this research uniquely highlights the muscle specific age related changes in mechanical performance and further indicates that the direct effect of caffeine changes with age.

Thesis (MSc (Physiological Sciences))--University of Stellenbosch, 2006. / This study aimed to assess the effect of mild psychological stress in male Wistar rats using incremental, intermittent stress on parameters of atrophy, including body mass, soleus and extensor digitorum longus (EDL) muscle mass, and mechanisms possibly contributing to atrophy. Serum corticosterone concentrations, 20s proteasome activity, glutamine synthetase (GS) and tyrosine amino-transferase (TAT) activities were determined. I also assessed whether Sutherlandia (Su) or resistance exercise was able to reverse the effects of stress on any of these parameters.

This study focused on nurses who work the night shift, and on some of the aspects of their lives. The objectives of the study were to identify and describe these experiences with specific reference to the physical, social and work-related effects.

Jealousy is understood as a system of physiological, behavioral, and emotional responses, yet few studies have examined these aspects of jealousy simultaneously in infants. Further, jealousy paradigms have not been examined as a potential stressor in infancy and thus typical cortisol reactivity and regulation patterns in response to jealousy paradigms have not been observed. In addition, the contribution of attachment security to infant expressions of jealousy has been vastly understudied. The present study seeks to fill the current gaps in the infant jealousy literature by investigating quantitative and qualitative changes in infant jealousy across the first two years of life. Data was collected longitudinally and mother- infant dyads were asked to participate when infants were 12- months and 24-months of age. Associations between behavioral jealousy responses, baseline EEG activity, stress reactivity and attachment security were examined. Differences in approach behaviors and behavioral arousal were found across conditions and were consistent with previous studies (Hart & Carrington, 2002; Mize & Jones, 2012). Findings relating to EEG activity pointed to a relationship between left EEG asymmetry and global approach behaviors across time. Cortisol reactivity was found to be associated with attachment security but reactive cortisol concentrations compared to baseline cortisol concentrations do not indicate that the paradigm was an effective stressor. Attachment security was found to be associated with proximity behaviors in 12- month olds but not 24-month olds. Finally, a linear regression revealed that attachment security, EEG asymmetry, and cortisol reactivity at 12-months are significant predictors of behavioral jealousy responses at 24-months. Changes in behavioral and physiological measures across time indicate that jealousy continues to develop during the second year of life but may have different underlying processes than the processes that contribute to jealousy expression in 12-month-olds. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The primary purpose of this study was to investigate the effect of acute high-intensity interval exercise (HIIE) vs. continuous moderate-intensity exercise (CME) on serum CTRP9 and brachial FMD responses in obese and normal-weight subjects. Sixteen participants (9 obese and 7 normal-weight) completed HIIE and CME in a randomized fashion. Our results showed a significant time effect for CTRP9 immediately following acute HIIE and CME in both groups. Furthermore, both significant treatment by time and group by time interactions for FMD were observed following both exercise protocols, with greater CME-induced FMD response in obese subjects than normal-weight subjects. Additionally, a positive correlation in percent change (baseline to peak) between CTRP9 and FMD was observed following acute CME. These findings support acute CME for improvement of endothelial function in obesity. Furthermore, the novel results from this study provide a foundation for additional examination of the mechanisms of exercise-mediated CTRP9 on endothelial function. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection