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Browsing by Author "Aguiar, Elroy J"

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    A Comparison of Traditional Blood Flow Restriction Versus Band Tissue Flossing for Induction of Muscular Fatigue
    (University of Alabama Libraries, 2021) Jones, Morgan Taylor; Winchester, Lee J; University of Alabama Tuscaloosa
    Resistance training with blood flow restriction (BFR) exaggerates metabolic stress and increases the number of muscle fibers recruited, resulting in greater improvements in muscular strength. An alternative method for occluding blood flow is band tissue flossing (BTF), in which an elastic band is wrapped around the limb. PURPOSE: The purpose of this study was to compare the effects of BTF to BFR on muscular fatigue. METHODS: Fifteen subjects (6 females; mean ± SD: age = 23.3 ± 0.1y, BMI = 25.7 ± 0.9kg/m2, thigh circumference = 59.9 ± 1.6cm) completed 3 sessions on separate days, each under a different condition: control (CON), BFR at 50% limb occlusion pressure, and BTF. During each session, participants performed maximal effort leg extension and flexion for 3 sets of 20 repetitions using an isokinetic dynamometer. At the start of each session, baseline heart rate (HR), lactate, glucose, and blood flow were recorded. During the BFR and BTF sessions, HR and blood flow were recorded before and 1-minute after occlusion. HR, glucose, and lactate were recorded immediately post- and 1-minute post-exercise for all sessions. Repeated measures ANOVAs were used to compare outcome measures between time points as well as between conditions. RESULTS: BFR and BTF both caused significant increases in HR compared to baseline (4.67 ± 2.14 BPM and 6.07 ± 2.56 BPM, both p < 0.01, respectively), with no significant differences between conditions. BTF significantly decreased arterial distance (-0.04 ± 0.04cm, p = 0.001), volume flow (-7.56 ± 6.88 cc/min, p = 0.001), and arterial area (-0.02 ± 0.01cm2, p < 0.001). Whereas BFR significantly decreased time-averaged mean velocity (-1.03 ± 1.65cm/s, p = 0.001). BTF caused a greater reduction in arterial distance compared to BFR (p = 0.006). However, no differences were observed in all dynamometry, electromyography, glucose, or lactate measures between occlusion conditions. CONCLUSION: BTF occluded more blood flow and yielded comparable changes in muscular fatigue when compared to BFR, providing an inexpensive training alternative when more sophisticated laboratory techniques are unavailable.
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    Effects of Proximal Limb Blood Flow Restriction Training on Distal Limb Performance and Recovery
    (University of Alabama Libraries, 2021) Saffold, Keith; Winchester, Lee J; University of Alabama Tuscaloosa
    Purpose: To determine if proximal limb blood flow restriction (BFR) influences muscular performance and recovery of the distal limb musculature (i.e., gastrocnemius, soleus, and tibialis anterior). Methods: Participants (N = 20; M±SD: 23.0 ± 3.8 years; 174.1 ± 9.0 cm; 77.9 ± 13.0 kg; 23.8 ± 8.6%body fat) completed a baseline visit and two experimental conditions consisting of exercise only (control; CON) and exercise with BFR. CON and BFR were performed in a counter-balanced order. Personal tourniquet pressure (PTP) was determined in each leg using the Delfi PTS II system at the BFR session only. Participants underwent the following assessments before and after each experimental visit: anatomical cross-sectional area (CSA) of the gastrocnemius, toe tap test, average stride length test, and counter-movement jump. The exercise protocol consisted of 3 sets of 15 repetitions of ankle plantarflexion (PF) and dorsiflexion (DF at 60 and 500 degrees per second, respectively, using an isokinetic dynamometer. Average force per repetition and total work performed were measured by the isokinetic dynamometer for both PF and DF during exercise. The only difference between BFR and CON was the application of BFR during the exercise protocol (unilateral occlusion at 80% of PTP, applied 30 s before initiating exercise on each leg). Two-way repeated measures analysis of variance (ANOVA) was performed to determine if changes in CSA, and measures of muscular strength and performance differed by BFR application (condition x time). Significance was set as p<0.05. Results: Average force per repetition and total work performed was lower during BFR compared to CON for both PF and DF (p<0.05 for both). CSA was increased post- versus pre-exercise following BFR compared to CON (p<0.05). Likewise, toe taps and stride length performance was decreased post- versus pre-exercise following BFR compared to CON(both p<0.05). Jump height decreased post- compared to pre-exercise with no difference between conditions (p<0.05). Conclusion: The addition of BFR to exercise elicited higher levels of muscular fatigue and decreased muscular performance compared to CON. These impairments were far greater than expected, producing significant reductions in force production, neuromuscular activation, and recovery rate.
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    The Efficacy of Performance Tests and Testing Instruments within Elite Female Volleyball Players
    (University of Alabama Libraries, 2023) Wright, Will C; Esco, Michael R
    With the plethora of available tests and testing devices for both the vertical jump and change of direction ability, evaluating the efficacy of these methods and systems is a valuable pursuit for researchers and practitioners alike. Specifically, evaluating the efficacy of these methods within a highly trained population that emphasizes vertical jump and COD ability like volleyball would highlight changes that occur with high levels of specific training. Therefore, the purpose of this dissertation is to evaluate the agreement of common COD ability test, jump testing devices, and explore the utility of new technology for collecting data more effectively. The specific aims are as follows:Study 1: To evaluate the relationships of commonly used COD test (T-test, L-drill, and 5-10-5 shuttle) in Division I female volleyball players.Study 2: To determine the agreement of three devices assessing vertical jump performance with the criterion reference force plate system.Study 3: To compare the agreement between a motorized sprint resistance device, timing gates, and a global positioning system for total time to complete and peak velocity achieved during a commonly used change of direction drill in elite female volleyball players.
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    Health-Related Disparities Between Young Adult Sexual Minority and Heterosexual Women
    (University of Alabama Libraries, 2023) Sullivan, Katherine; Fedewa, Michael V
    The negative physical and psychological health outcomes which disproportionately affect sexual minority women (SMW), when compared to heterosexual women (HSW), may be attributed to community-wide perceptual differences in self-evaluation and/or the chronic exposure of sexual orientation-related psychosocial stressors (i.e., discrimination, stigma, prejudice, etc.). The limited research which has examined the potential effect of sexual orientation on negative health outcomes has yielded inconsistent results. Furthermore, there is a paucity of research specifically focusing on young adult women, who represent a unique subgroup of the population. The general purpose of this dissertation was to expand upon this understudied area with three separate research studies. Study 1 examined potential differences in relative adiposity (%Fat) and body dissatisfaction (BD) between young adult SMW and HSW. When comparing a combined group of SMW to HSW, SMW had moderately higher %Fat than HSW (p=.046, ES=.53); however, these results were not statistically significant when SMW were split into two groups, lesbian/gay and bisexual/plurisexual, and compared to HSW (V=0.064, F(4, 162)=1.33, p=.263). No differences in BD were observed regardless of SMW groupings (?=0.90, F(8, 156)=1.05, p=.404). Linear correlations were observed between %Fat, BD, and sexual orientation, such that higher %Fat was associated with greater BD and that sexual minority status was associated with lower body dissatisfaction; however, lesbian/gay sexual orientation seemed to intensify the association between %Fat and BD. Study 2 examined potential differences in cumulative allostatic load and physical activity (PA) between young adult SMW and HSW. Results indicated no differences in cumulative allostatic load (F(1, 38)=0.206, p=.652) or PA parameters (p<.05 for all) between young adult SMW and HSW. Study 3 examined potential differences in PA behaviors between SMW and HSW through a systematic review and meta-analysis. Although the results indicated that there were no significant differences in PA between SMW and HSW (ES=-0.038, 95%CI -0.179 to 0.102, p=0.576), differences in PA were associated with age (?=-0.018, 95%CI -0.034 to -0.003, p=0.022) and body mass index (?=-0.145, 95%CI -0.228 to -0.061, p=0.002). The results of this dissertation highlight the need for additional research in order to better understand the complex association between sexual orientation and health-related behaviors and outcomes among women.
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    The Influence of Chronotype on Cardiovascular and Metabolic Health Profiles in Young Adults
    (University of Alabama Libraries, 2025) Reuben, Garrett Josiah; MacDonald, Hayley V
    BACKGROUND: Circadian rhythm is the process that regulates the sleep-wake cycle in our bodies, repeating approximately every 24 hours. This process controls various physiological processes, and when disrupted, circadian misalignments can lead to cardiometabolic dysfunction and disease. Chronotype is the behavioral manifestation of circadian rhythm, reflecting when one feels high or low energy during the day. Individuals are broadly categorized as morning (wake up early, feel most alert in the morning) or evening (wake up late, feel most alert in the evening) chronotype. Growing evidence suggests that an evening chronotype is associated with an unfavorable cardiometabolic risk profile in middle-aged and older adults. Less is known about chronotype and cardiometabolic risk in younger adults, resulting in a crucial gap in understanding how early-life behaviors influence long-term health outcomes. PURPOSE: To investigate the influence of chronotype on cardiometabolic health among young adults (18-40 y) using a comprehensive assessment battery and examine whether these differences are mediated by habitual lifestyle factors. METHODS: 68 young adults (20±3 y, 69% women, 72% White, 26.6±6.7 kg/m2) were stratified into two groups: morning (n=33) and evening (n=35) chronotype, using the Morningness-Eveningness Questionnaire. Participants underwent assessments of body composition, cardiometabolic health (e.g., blood pressure [BP]), arterial stiffness, fasted cholesterol and glucose levels), physical activity (PA), and sleep. Participants wore an ambulatory BP monitor and accelerometer to measure BP, PA, and sleep parameters for 24 hours. RESULTS: Greater eveningness was associated with less favorable behavioral profiles, including reduced light and moderate PA, more sustained inactivity, poorer sleep quality, greater social jetlag, and poorer diet quality (p≤0.05 for all). Individual cardiometabolic measures did not differ by chronotype, however, evening chronotype was associated with higher cardiometabolic risk using composite scores (Framingham risk, Life's Essential 8). No behavioral or sleep-related variables significantly mediated the association between chronotype and cardiometabolic risk. CONCLUSIONS: This study is among the first to comprehensively examine chronotype and cardiometabolic health in young adults using both self-report and device-based measures. Findings support an emerging role for chronotype in shaping cardiometabolic risk and highlight the need for longitudinal studies and tailored interventions addressing circadian alignment in at-risk individuals.
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    Resistance Trained Women's Response to Blood Flow Restriction Training
    (University of Alabama Libraries, 2023) Fleming, Abby; Winchester, Lee J
    Low-load resistance training (20-30% one-repetition max (1RM)) with blood flow restriction (LI-BFR) is able to induce similar strength, hypertrophic, and vascular adaptations to traditional high-load resistance training (>65% 1RM) (HIRT). Minimal research has been conducted examining the combination of HIRT and BFR (HIRT+BFR). Of the available research, the results are inconsistent, and none have looked at an exclusively female sample. With the lack of female participants in this specific area of research and training research in general, the need for further research in female subjects is necessary, as there are potential physiological adaptations from what is observed in males. The three studies of this dissertation were conducted to understand the physiological, vascular, and hormonal adaptations to HIRT+BFR training in resistance trained women. In study 1, 4-weeks of a lower-body HIRT+BFR training was implemented to determine changes in strength, muscle activation, movement velocity, and peak power. Results indicate similar adaptations between HIRT+BFR and HIRT alone for all measurements (all p > 0.05) except bar velocity during deadlift 1RM, where HIRT+BFR presented a decrease post-training (p < 0.05). Study 2 examined changes to vascular reactivity after the same 4-weeks of HIRT+BFR training. HIRT+BFR and HIRT produced similar changes to femoral and tibial arterial measurements (all p > 0.05). Acutely, during the initial 1RM testing session, the HIRT+BFR group significantly increased femoral artery time-averaged mean velocity (TAMV) from pre- to post- exercise (p = 0.007). During the final 1RM testing session there was also a time effect for femoral artery TAMV (p = 0.005), though only the HIRT group was significantly increased (p = 0.023). Study 3 examined the hormonal response to an acute bout of lower-body HIRT+BFR. There were no significant changes to dehydroepiandrosterone sulfate (DHEA-S) in either group (all p > 0.05). Insulin-like growth factor 1 (IGF-1), however, did trend towards a time effect (p = 0.051), where the HIRT+BFR group significantly increased post-exercise (p = 0.025). The combination of HIRT and BFR does not seem to enhance performance or vascular adaptations but may promote greater hormonal responses over HIRT alone.