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Arterial and Venous Adaptations to Short-Term Handgrip Exercise TrainingAlomari, Mahmoud Awad 04 September 2003 (has links)
Four studies on vascular and exercise physiology are presented in this document. The 1st study examined the relationships between measures of fitness and FVF in 55 young [22.6 ± 3.5 years] adults. Estimated VO<sub>2peak</sub> correlated with arterial inflow (Ainf) [r=0.54; p=0.012] and resting venous outflow (Vout) [r=0.56; p=0.016]. Lastly, HG strength was associated with Vcap [r=0.57; p=0.007] and Vout [r=0.67; p=0.001].
The 2nd study examined the relationship between FVF and exercise tolerance (ExT) in 20 patients with HF [age: 59 ± 13 years] and 10 age-matched controls [age: 51 ± 16 years. The ExT was measured as the maximum walking distance (MWD) in 6 minutes. FVF [Ainf: HF 15.3 ± 6; controls 22 ± 6.7; Vcap: HF 1.4 ± 0.5; controls 2.0 ± 0.4; Vout: HF 24.5 ± 9.4; controls 33 ± 10 mL · 100 mL tissue<sup>-1</sup> · min<sup>-1</sup>; and forearm vascular resistance: HF 7.8 ± 3; controls 4.6 ± 1.4U] indices and MWD [HF: 178 ± 65 m; controls: 562 ± 136m, P = .0001] were different between groups. Correlation analysis revealed significant associations between FVF indices and MWD.
The 3rd study examined the effect of 25% (LO) and 75% (HI) of MVC short-term HG exercise training on FVF in 28 healthy men [Age:23±4.3]. The 4-week program consisted of non-dominant HG exercise performed 5 d/wk for 20-min. Training resulted in increased Ainf in the non-dominant arm in the LO and HI groups by 16.51% and 20.72%, respectively.
The final study examined the time-course FVF adaptations to HG exercise training in 17 men [Age: 22.6 ± 3.5]. The HG exercise was performed in the non-dominant arm 5 d/wk for 20-min at 60% of MVC. The 2 X 5 ANOVA revealed arms X visits interaction for Ainf [p=0.02], while the LSD post-hoc demonstrated unilateral increase in Ainf following the 1st week. Additional 2 X 5 split-plot ANOVA tests revealed arms X visits interaction [p=0.04] for venous compliance (Vcomp) with LSD post-hoc demonstrating a decrease in trained arm Vcomp in visit 2 followed by an increase in visit 4 and return to baseline level at visit 5.
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Using Self-Determination Theory to Understand African American Women's Physical Activity PatternsLandry, Joan B. 29 January 2003 (has links)
Physical inactivity is a major health risk factor in our society. Women and minority populations are especially at risk with regard to physical inactivity. This three-part study employed quantitative and qualitative methodologies to investigate physical activity behaviors in middle aged and older African American women. This population was chosen because African American women are the least active segment of our society. In the first phase, a quantitative approach was used to investigate relationships between Self-Determination and the Stage of Change for physical activity in a sample of 105 African American women. This study provided validation for using this theoretical approach in a population of African American women and provided a clearer understanding of the types of motivation most likely to contribute to the initiation and maintenance of exercise in this population. Guided by the underlying assumption that the reasons African American women choose to be active or inactive can only be fully understood by carefully examining their perspectives, a qualitative approach was used in the second and third phases of the study. Fifteen physically active and fifteen physically inactive women were purposively selected from the initial sample for in depth interviews in phase two. Categorical and contextual analysis indicated that perceptions of health status were a powerful influence on physical activity behavior. Perceptions of health status reflected the beliefs individuals held about a particular disease or physical condition, and the limitations they associated with that condition. In the third phase, six participants were selected for a multiple case study design. Cases analysis revealed that women shaped their physical activity patterns around their understanding of how physical activity would directly influence their desire to maintain independence from health costs, physical limitations related to their health, expected age related decline and their dependence on others. Across each phase of this project, identifying an individuals level of motivation, as well as exploring the influences of that individuals social context in a particular stage of change, has contributed to our understanding of factors to consider when developing effective behavior change interventions in this population.
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Examining the Relationships between Ability Conceptions, Intrinsic Motivation, Persistence, and PerformanceLi, Weidong 02 March 2004 (has links)
The purpose of this study was to examine the relationships between ability conceptions, intrinsic motivation, persistence, and performance using an interaction approach. The phase-one study revealed that participants who were more oriented toward incremental ability beliefs were likely to be more intrinsically motivated. For those who were more intrinsically motivated, they displayed more persistence and obtained better performance scores. Participants who were highly intrinsically motivated had lower performance scores as they were more oriented toward incremental ability beliefs. The phase-two study showed that participants who were more oriented toward incremental views were more intrinsically motivated, which provided evidence supporting the important role of dispositional ability conceptions in mediating intrinsic motivation. Participants who were more intrinsically motivated had better performance scores. Participants with high levels of intrinsic motivation in the incremental condition persisted longer than those in the entity condition. The results suggest that when studying the effects of situational ability conceptions on motivational patterns dispositional ability conceptions should be considered. It is also suggested that if physical education teachers want to improve students learning outcomes a positive environment should be created, whereby their perceptions of competency and intrinsic motivation will be enhanced. Finally, an interaction approach promises to provide a deeper understanding of how motivational constructs interact to affect students motivational patterns.
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The Effectiveness of Videotape Feedback in Sport: Examining Cognitions in a Self-Controlled Learning EnvironmentMenickelli, Justin 06 April 2004 (has links)
Providing videotape feedback (VTFB) as a form of knowledge of performance (KP) to learners is a common instructional tool in teaching and coaching. VTFB has attracted renewed attention and various laundry lists of recommendations (e.g., provide VTFB immediately following performance, use frequently, vary camera angles) on VTFB implementation (e.g., Franks & Maile, 1991; Trinity & Annesi, 1996). Furthermore, researchers have begun exploring the cognitive variables which serve to mediate the impact of VTFB (e.g., Hebert, Landin, & Menickelli, 1998; Menickelli, Landin, Grisham, & Hebert, 2000). Recent research has focused on two key issues: VTFB provided in a self-controlled learning environment and learners cognitions during VTFB exposure.
This purpose of this study was to investigate the unique contributions of four augmented feedback modalities on learning a multiple degrees-of-freedom skill: Self-controlled VTFB (SC-VTFB), instructor-controlled VTFB (VTFB), self-controlled verbal KP (SC-KP), and instructor-controlled verbal KP (KP). Also, to examine learners cognitions as a potential underlying mechanism of self-controlled VTFB and self-controlled verbal KP. Male, right handed participants (N=48) were randomly assigned to one of the four experimental conditions. The task consisted of performing a forehand throw using a standard flying disc (175 g., 27 cm diameter), commonly referred to as a frisbee.® The dependent measures of the study included throwing form, throwing error measures, and learners cognitions during feedback sessions.
In general, the results indicated that both self- and instructor-controlled VTFB was more effective than either self- or instructor-controlled verbal KP in learning a multiple degrees-of-freedom skill. Some support for a self-controlled schedule of feedback was found in that self-controlled learners were able to recognize errors and tendencies in their throwing form early in acquisition. Also, self-controlled learners, regardless of the type of feedback provided, unknowingly requested a fading schedule of feedback. These findings endorsed self-control as a means to cognitively engage learners.
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Leg-Extensor Strength and Continuous-Scale Physical Functional Performance in Independent-Living Older AdultsWilson, Kathryn O'Bryan 13 August 2002 (has links)
A clear relationship between age-related decrements in leg strength and physical function have been reported. The purpose of this investigation was to describe the relationship between quadriceps strength tested at various velocities and the CS-PFP 10 items. Thirty-three older adults (ages 70-95 years) were assessed using the CS-PFP 10 test battery and performed quadriceps strength testing at 0, 90, 180º/sec using the Biodex dynamometer. Values for torque are reported as peak torque (PT) and relative peak torque (AdjPT) in Nm/kg body weight. The range of values for PT was (PT0: 20.2-144.3 Nm; PT90: 14-113.6 Nm; PT180: 9.6-86.4 Nm). Simple correlation revealed age was inversely related to quadriceps strength (with PT0, r=-0.368; PT180, r=-0.384), while nearly significant at PT90 (r=-0.339, p=0.54), and the overall CS-PFP 10 scores (r=-0.657, p<0.001). However, when treating the data according to gender, the relationship between age and strength did not achieve significance for either males or females. Age was associated with several of the individual CS-PFP items. Results also revealed relationships between absolute strength and CS-PFP 10 scores (PT0 r=0.622 p<0.001; PT90 r=0.683 p<0.001; PT180 r=0.614 p<0.001). Moreover, the association between age and function appeared somewhat similar for males (-0.621) and females (-0.678). However, the male subjects also showed associations between relative strength (AdjPT90 and AdjPT180) and CS-PFP10 scores, while females revealed an association between relative strength and function at 0 per second, only. Lastly, curve fitting revealed that the association between strength and function in this group of older adults is linear, thereby suggesting the absence of an identifiable functional threshold above which an increase in strength would not result in an increase in function. The results are consistent with age-related decrements in functional fitness and quadriceps strength. In each case these correlation coefficients suggest that greater levels of strength were associated with greater functional performance. Furthermore, these data suggest that absolute strength may be better associated with physical functioning than relative strength. Future research should continue to search for thresholds of strength as they relate to physical functional ability.
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Reliability of Wavelet Analysis of Heart Rate Variability during Rest and ExerciseStone, Deborah Jean 25 November 2002 (has links)
The reliability of wavelet analysis (DWT), of heart rate variability during rest and exercise was examined for this study.
All twenty-three participants visited the lab on two separate occasions no less than four weeks apart. All twenty-three participants were subjected to the spontaneous breathing (SB1), and HG60 exercise condition. Of those twenty-three participants, nine performed the HG20 exercise condition as well.
It was found that during the SB1 condition, the R-R intervals were fairly reliable between days. However, the reliability of all the HRV parameters (SDNN, spectral components and wavelet components) were quite poor. Interestingly, however, during HG20, the reliability of the HRV parameters was much more promising.
The ability of DWT to detect changes in sympathovagal balance with incremental handgrip exercise was seen, despite a very low number of participants.
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Hemodynamic Responses Following Dynamic Resistance Exercise in Young and Older Adult WomenReyes, Rafael Antonio 08 April 2004 (has links)
This investigation examined the effects of age, exercise and test condition on hemodynamic variables, autonomic and vascular function in relation to resistance exercise (RE). The associations among these variables were also examined. METHODS: Sixteen young (21.4+1.4 yrs) and 16 older (69.7+3.9 yrs) women performed 5- and 15- repetition maximal (RM) of knee extension RE. Continuous blood pressure (BP) and electrocardiography (ECG) data were recorded. The dependent variables are reported at pre-exercise, peak exercise and recovery period. Heart rate variability data were derived from 5- and 10-min segments before and after exercise. Resting and after arterial occlusion forearm vascular function indices and pre- and post-exercise resting forearm blood flow and forearm vascular resistance (FVR) were measured using plethysmography technique. ANOVA with repeated measures was used for statistical analysis. LSD was used where post hoc comparison required. Pearson correlation and linear regression were used to examine associations between autonomic and vascular function indices and hemodynamic parameters; alpha=0.05. RESULTS: Resistance exercise resulted in increased BP (SBP=36.6+2.2; DBP=27.4+1.6 mmHg) and HR (37.8+1.6 beat/min). This was followed by a drop in BP below pre-exercise level throughout the recovery period up to 60 minutes. The 15-RM condition resulted in higher SBP at peak exercise (15-RM: 155.7+3.7 vs. 5-RM: 142.3+3.7 mmHg) and in the early phase of recovery (local min: 15-RM=127.0+2.7 vs. 5-RM=120.4+2.6 mmHg); however, the 5-RM condition resulted in greater 1-min and 3-min post-exercise SBP recovery ratios (15-RM: 1-min=0.78+0.01; 3-min=0.76+0.01 vs. 5-RM: 1-min=0.84+0.01; 3-min=0.82+0.01). Older women had higher SBP throughout the testing period, and higher 1-min and 3-min recovery ratios (Young: 1-min=0.80+0.01; 3-min=0.78+0.01 vs. Old: 1-min=0.83+0.01; 3-min=0.80+0.01). However, the older women experienced greater drops in BP (SBP: young=-0.02+2.6 vs. old=-9.4+2.3; DBP: young=-3.5+1.8 vs. old=-9.8+1.9 mmHg) during the recovery period. FVR after RE increased above pre-exercise only in the young (p<0.03). Low-frequency variations in HR were related to recovery of mean arterial pressure (young: r=0.66, p<0.001; older: r=0.79; p<0.001) and FVR (young: r=0.93, p=0.001; old: r=0.95; p<0.001). CONCUSION: Age-group differences in post-exercise BP drop, characterized by a greater decline in BP in older adults, might be attributed to smaller increases in vascular resistance in older women.
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An Examination of the Relationship between Psychological Conditions and the Incidence of Athletic InjuryPenczek, Gregory A 15 April 2004 (has links)
The purpose if this investigation was to examine injury rates among college athletes with a diagnosed psychological condition/mental disorder. Participants were drawn from a pool of 440 male and female intercollegiate athletes (ages 18-26 years). All subjects with a psychological disorder were then identified (n=38) and placed in the diagnosis group. A second group was then selected, which consisted of matched pairs of athletes without a psychological diagnosis. Twelve sports were represented in the sample population with an equal number of male (n=26) and female (n=12) participants in each group. The athletic training database was examined via query to identify each athletes specific psychological diagnosis (or lack thereof), number of injuries, and injury severity per occurrence. Chi-square analysis revealed that subjects in the diagnosed group suffered a significantly higher frequency of total injuries than subjects in the non-diagnosed group. Further analysis of injury severity within the two groups showed that diagnosed males had a higher frequency of mild and moderate injuries than non-diagnosed males. A significant difference was also found between females in each group, with diagnosed females have a higher frequency of mild injuries. Examination of gender differences within each group revealed that diagnosed males had a higher frequency of mild and moderate injuries than females, while analysis of the non-diagnosed group showed a higher frequency of mild injuries in males, and moderate injuries in females. Further analysis of overall gender differences revealed that males had a higher frequency of mild and severe injuries when compared to females. The results of this study are consistent with previous research findings that suggest increased stress predisposes an athlete to injury. Future research should continue to examine the relationship between psychological conditions and the incidence of athletic injury.
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Brachial Artery Dimensions, Flow-Mediated Reactivity, and Physical Function in Older AdultsKing, Christina M. 14 April 2004 (has links)
Human aging is associated with deterioration in physical functional ability. The causes are complex and multifactorial, but are presumed to include the presence and extent of cardiovascular disease. Purpose: To examine the associations between brachial artery (BA) dimensions, flow-mediated dilation (BAFMD) and physical function in 28 older adults (age: 84.6±10.9, range 66 to 98 yrs). Methods: High-resolution ultrasonography was used to measure BA diameters at rest and following 5min of forearm occlusion. Physical function was assessed using the Continuous Scale-Physical Function Performance (CS-PFP) test. Results: Pearson correlation revealed that BAFMD (r =-.39), and all physical function parameters of the CS-PFP declined with age at an alpha of p= .04 and p< .01, respectively (UBS, r= -.69; UBF, r= -.78; LBS, r= -.77; BALCOR, r= -.74; END, r= -.81; PFP total score, r= -.79). Six-minute walk scores (a component of the CS-PFP) also declined with age (r= -.72, p <0.01). Mean BA resting diameter and BAFMD were 4.31±0.77mm and 1.89±1.99%, respectively. Resting diameter was inversely associated with BAFMD (r= -.45, p= .02). Partial correlation (controlling for BMI) was used to account for the influence of participant size on vascular and physical function measures. The results indicated an association between BAFMD and several CS-PFP sub-scales with an alpha of p< .05 (END, r= .40; UBF, r= .39; LBS, r= .39; BALCOR, r= .38). CS-PFP total score (r= .38) and UBS (r= .28) were associated with BAFMD at alpha of p= .06 and p= .18, respectively. Notedly, the difference between resting and peak diameters, as a group, was not significant for the study sample. Two participants in the study sample had BAFMD> 5%, thus the sample was biased towards non-responders. Conclusion: These results appear to confirm predicted trends for physical function decline and reduced vasoreactivity in older adults. Uniquely, this study is the first to suggest a link between BA reactivity and age-appropriate measures of physical functional status. Therefore, BAFMD could potentially provide information regarding the impact of CVD and vasoreactivity on the functional characteristics of the population.
Funded by the Louisiana Board of Regents Millennium Trust Health Education Fund.
[I HEF (2001-06)-02]
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Influence of Venous Emptying on Reactive Hyperemic Blood FlowBahadir, Zeki 15 April 2004 (has links)
Recent work by Tschakovsky & Hughson (Am J Physiol Heart Circ Physiol 279: H1007, 2000) indicates that venous emptying serves as a stimulus for vasodilation. This suggests the importance of recognizing the potential influence of venous volume on reactive hyperemic blood flow (RHBF) following occlusion. Purpose: To examine the influence of venous emptying on RHBF. Methods: Non-dominant forearm in-flow, venous capacitance and outflow were examined in 21 individuals [age=23±2.27y]. Forearm arterial inflow, venous capacitance, and outflow were obtained two times using strain gauge plethysmography. Forearm blood inflow was estimated at rest and following 5 min of upper arm occlusion. Forearm venous capacitance and outflow were obtained following 5 min of upper arm venous occlusion pressure at 7 mmHg below diastolic blood pressure. Prior to the second measure the arm was passively elevated for 2 minutes. Immediately before returning the arm to its original position the upper arm cuff was again inflated to 240mmHg. Subsequently, RHBF and venous measures were obtained. Results: Average resting in-flow was 2.84±1.22 ml/100ml/min. RHBF was significantly greater following venous emptying (Before: 18.15±3.80; After: 23.70±5.93 ml/100ml/min, p=0.0001). Venous capacitance was also greater (Before: 1.96±0.82; After: 2.94±0.82 %, p=0.0001), whereas venous outflow (Before: 37.06±10.50; After: 39.00±10.72 ml/100ml/min, p=0.17) remained unaffected after venous emptying. Summary: Venous emptying prior to upper arm occlusion results in a significant greater RHBF response and venous capacitance. A potential explanation for the observation is a decrease in the pressure gradient across the tissue bed and/or withdrawal of the venoarteriolar reflex constriction.
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