Ulku Karabulut - Academia.edu (original) (raw)

Papers by Ulku Karabulut

International journal of aquatic research and education, Jul 1, 2018

Available research clearly shows that more children who have disabilities, including those with s... more Available research clearly shows that more children who have disabilities, including those with severe disabilities, are participating in swimming programs as well as wanting to be taught in a regular aquatic class without being segregated. Aquatic instructors need to prepare lessons that include children both with and without disabilities. This means that aquatics instructors need to understand and be willing to implement unique teaching and managerial techniques that foster the safe and successful learning environment for all children. While the task of teaching children who have severe disabilities may seem difficult at first, with a little knowledge and experience, instructors can become better teachers to all children, gain confidence in their instructional skills, and see more positive and successful performances in their aquatic programs.

Clinical Physiology and Functional Imaging, Apr 4, 2018

The aim of this study was to assess the effect of isometric exercises performed during whole-body... more The aim of this study was to assess the effect of isometric exercises performed during whole-body vibration (WBV) with and without blood flow restriction (BFR) on arterial elasticity and hemodynamic variables. Methods: Eight male subjects performed static upper body (UB) and lower body (LB) exercises on a vibration platform with and without BFR. During BFR sessions, BFR cuffs were placed on the arms or legs and inflated to a target pressure. Exercises consisted of eight 45-s sets for UB, and ten 1-min sets for LB. Arterial elasticity and hemodynamic variables were assessed before, at 10 min and 40 min postexercise. Repeated measures ANOVA was used to test the mean differences in related variables. Results: A significant condition (BFR versus no-BFR) main effect was detected for small arterial elasticity (P<0Á05). For heart rate (HR), there were significant time (P<0Á01), condition (P = 0Á02) and body (P = 0Á04) main effects during exercise and condition (P<0Á04) and time (P<0Á01) main effects following exercise. Significantly lower values in systemic vascular resistance were detected at 10 min post compared to 40 min post (P<0Á02) and UB compared to LB (P = 0Á02). Conclusions: Results showed that small arteries stayed stiffer for a longer period of time after vibration exercises with BFR and BFR placed a greater demand on cardiovascular system. Findings also indicated that the type of exercises performed and/or the measurement location are very important and should be taken into account when examining arterial response.

Medicine and Science in Sports and Exercise, Jul 1, 2020

Medicine and Science in Sports and Exercise, May 1, 2017

The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) mu... more The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) muscle as measured by electromyography (EMG) following short-term resistance training with and without blood flow restriction (BFR). METHODS: 12 males (age = 27.4 ± 6.3 years; height = 171 ± 7 cm; weight = 79.8 ± 13.2 kg) performed six sessions of lower body unilateral resistance training using a leg extension machine. The leg on which BFR was applied was determined through randomization leg dominance Each training session consisted of unilateral knee extensions with and without blood flow restriction. Electromyography data was recorded for each participant during two isometric maximum voluntary contractions (MVC) and two isokinetic knee extension tests (180°/s and 60°/s) using a Biodex System 4 Pro™. EMG was recorded from the RF during these tests. Resistance training consisted of six non-consecutive sessions of knee extension exercises performed in a time frame of two weeks. For the BFR group, subjects trained for a total of four sets (30, 15, 15, 15) at an intensity of 20% 1RM. The contralateral limb was trained with two sets of 11 repetitions at an intensity of 70% 1RM without BFR. The volume of exercises was similar for both conditions. RESULTS: No condition*time interactions or condition and time main effects were observed for root mean square (RMS), mean RMS, yMax, and median frequency (MDF) in both MVC and isokinetic 180°/s and 60°/s (p>0.05). CONCLUSIONS: Both training conditions resulted in insignificant changes and there was no significant difference found between time points. It could be concluded that this was not enough time or stimulus to note major differences across modalities in relation to neuromuscular adaptations of the RF as measured by EMG. Further studies should investigate the effects of higher volume load on neuromuscular adaptations.

International Journal of Exercise Science: Conference Proceedings, 2017

The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) mu... more The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) muscle as measured by electromyography (EMG) following short-term resistance training with and without blood flow restriction (BFR). METHODS: 12 males (age = 27.4 ± 6.3 years; height = 171 ± 7 cm; weight = 79.8 ± 13.2 kg) performed six sessions of lower body unilateral resistance training using a leg extension machine. The leg on which BFR was applied was determined through randomization leg dominance Each training session consisted of unilateral knee extensions with and without blood flow restriction. Electromyography data was recorded for each participant during two isometric maximum voluntary contractions (MVC) and two isokinetic knee extension tests (180°/s and 60°/s) using a Biodex System 4 Pro™. EMG was recorded from the RF during these tests. Resistance training consisted of six non-consecutive sessions of knee extension exercises performed in a time frame of two weeks. For the BFR group, subjects trained for a total of four sets (30, 15, 15, 15) at an intensity of 20% 1RM. The contralateral limb was trained with two sets of 11 repetitions at an intensity of 70% 1RM without BFR. The volume of exercises was similar for both conditions. RESULTS: No condition*time interactions or condition and time main effects were observed for root mean square (RMS), mean RMS, yMax, and median frequency (MDF) in both MVC and isokinetic 180°/s and 60°/s (p>0.05). CONCLUSIONS: Both training conditions resulted in insignificant changes and there was no significant difference found between time points. It could be concluded that this was not enough time or stimulus to note major differences across modalities in relation to neuromuscular adaptations of the RF as measured by EMG. Further studies should investigate the effects of higher volume load on neuromuscular adaptations.

Medicine and Science in Sports and Exercise, Jun 1, 2019

To determine the effects of guideline recommended hypertrophy and blood flow restriction training... more To determine the effects of guideline recommended hypertrophy and blood flow restriction training protocols on pulse wave velocity in recreationally active males. METHODS: Fourteen male subjects (age= 23.7±2.6) were randomly assigned to one of two groups that trained the knee flexors, extensors, and split squat for 6 weeks. The two training groups included: a blood flow restriction group (BFR, N=8) and hypertrophy (HYP, N=6). All training groups began with subjects warming up on the cycle ergometer at 50 rpm with 2.0 kg resistance and subjects were then lead through the resistance training programs that remained constant for each session thereafter. The HYP group followed NSCA guideline for recommended intensity, set, and rest period. The HYP group performed exercise for 4 sets of 10 repetitions 3x/wk at 75% of 1RM with 90 second rest between each set. The BFR group performed exercises for 4 sets of 30, 15, 15, 15 reps 3x/wk at 40% of 1RM with 30 second rest between each set. Each training session was monitored by a trained individual to make sure the correct breathing pattern were maintained during lifts to avoid the Valsalva maneuver. As for pre and post testing sessions, fasted subjects (for at least 8 hours) reported to the lab and hydration level was assessed by clinical urine refractometer before testing sessions. PWV was measured non-invasively using applanation tonometry, in which a probe was used on the surface of the skin over the carotid, radial, femoral, and pedal arteries to obtain segmental measures. RESULTS: One-way ANOVA found no between-group differences in any of the outcome measures of interest at baseline. There were no significant condition main effects for carotid-radial (CR), carotid-femoral (CF), femoral-distal (FD), however a significant time main effect was detected for CF (p < 0.05). CF-PWV significantly decreased from baseline to post testing. CONCLUSIONS: The findings of the study suggest that both BFR and HYP training programs are similarly effective in decreasing the central arterial stiffness. The data also indicates that avoiding the Valsalva maneuver may be necessary for positive changes in aortic stiffness and BFR training protocol can be used an alternative method for those who can't or do not want to lift high loads to improve central arterial elasticity.

Medicine and Science in Sports and Exercise, May 1, 2016

High-intensity functional training (HIFT) is a relatively new mode of training that is gaining po... more High-intensity functional training (HIFT) is a relatively new mode of training that is gaining popularity among the general population. A recognized form of HIFT is CrossFit™, which is defined as a program of "constantly varied, high-intensity, functional movements." Although there are purported improvements in strength and body composition with this training modality, there is a lack of empirical evidence to support these claims. PURPOSE: The purpose of this study was to examine changes in body composition and strength among apparently healthy individuals following 16-weeks of HIFT. METHODS: 53 individuals originally signed up for the study. Testing sessions included pre and post measures for body composition (Dual-Energy X-Ray Absorptiometry) and strength (5RM Front squat). Training included participation in HIFT a minimum of twice a week for 16-weeks. RESULTS: 26 individuals (49%) completed the 16-week program and provided all required measures. Repeated measures analysis of variance revealed no gender effect on strength or body composition outcomes. Paired-sample t-tests showed significant improvements in the front squat (Males

Medicine and Science in Sports and Exercise, May 1, 2016

The aim of the study was to assess the effect of dynamic upper and lower body vibration exercises... more The aim of the study was to assess the effect of dynamic upper and lower body vibration exercises with blood flow restriction (BFR) on arterial elasticity and hemodynamic variables. METHODS: Seventeen male subjects (age= 23.8±24.9) performed dynamic push-up (PU) or squat (SQ) exercises on a vibration platform set at 30 Hz with and without BFR. During BFR sessions, BFR cuffs were inflated to a pressure of 100 mmHg for PU and to a pressure determined by multiplying the arm systolic blood pressure by 1.44 for SQ. Exercises consisted of eight 45s sets for PU, and for ten 1min sets for SQ. Arterial elasticity and hemodynamic variables were assessed before by non-invasive methods using the radial artery tonometer, at 10min, 20min, and 40min post-exercise. RESULTS: There were significant body*time interaction (p< 0.02) and main effects for body (SQ vs. PU) (p< 0.04) and time (p<0.01) for large arterial elasticity. There was also a body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.01) for vascular resistance. There was a significant time main effect for systolic blood pressure, but a body*time interaction (p<0.01) and time main effect (p<0.01) were detected for diastolic blood pressure. There were significant body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.05) for pulse pressure. There were significant body*time interaction (p< 0.01) and main effects for condition (p< 0.03), body (p< 0.01), and time (p<0.01) for pulse rate. Significant main effects for condition (p< 0.04) and time (p<0.01) were detected for cardiac ejection time. There were significant body*time interaction (p< 0.01) and time main effect (p< 0.01) for stroke volume. There was also a body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.01) for cardiac output. CONCLUSION: Combining dynamic vibration exercise with BFR changed the pattern and the level of changes in pulse rate and cardiac ejection time, which could be explained due to lower venous return. The responses in several variables were greater following PU indicating that the importance of type of exercise performed and/or the site of measurement taken. Future studies should investigate acute and chronic effects of different type and intensity of BFR exercises with vibration on arterial compliance.

Medicine and Science in Sports and Exercise, May 1, 2016

PURPOSE: To investigate the relationship between anthropometric measures, blood pressure (BP), to... more PURPOSE: To investigate the relationship between anthropometric measures, blood pressure (BP), total cholesterol (TC), fasting blood glucose (FBG), and high density lipoprotein cholesterol (HDL) among Hispanic college-aged males 18 to 30 in the Lower Rio Grande Valley. METHODS: Thirty-five male subjects (age= 23.2 ± 2.8) read and signed the informed consent prior to participation in this study. Subjects had their height, weight, and three circumference measurements taken [waist at umbilicus (WU), waist at smallest point (WSP), and hip at widest point (HWP)] and their body mass index (BMI) calculated. A fasting blood sample was taken to analyze TC, HDL, and FBG; in addition, TC:HDL ratio and non-HDL were calculated. Percent body fat (BF) was also measured using air displacement plethysmography. RESULTS: Age was found to be significantly correlated with weight (r= 0.491, p< 0.01), BF (r= 0.575, p< 0.01), BMI (r= 0.539, p< 0.01), diastolic (DBP) (r= 0.427, p< 0.01), WSP (r= 0.596, p< 0.01), WU (r= 0.638, p< 0.01), and HWP (r= 0.485, p< 0.01), and non-HDL (r= 0.405, p< 0.02). BF and BMI were significantly correlated with HDL (r= −0.370, p< 0.03; r= −0.384, p< 0.03) and correlated with TC:HDL ratio (r= 0.466, p< 0.01; r= 0.441, p< 0.01). WSP, WU, and HWP were significantly correlated with TC:HDL ratio (r= 0.429, p< 0.01; r= 0.449, p< 0.01; r= 0.372, p< 0.03), while only the WU and HWP circumference measurements were significantly correlated with HDL cholesterol (r= −0.369, p< 0.03; r= −0.428, p< 0.01). CONCLUSIONS: The results indicated age had notable correlations across most measures, even within this small 12-year range, which may be due to a decrease in physical activity throughout the college career. The data indicated higher BMI and BF were similarly correlated with lower HDL blood concentration and an increased TC:HDL ratio. This suggests that BMI is still a strong predictor of cholesterol level and can be relied upon when body composition analyzation is not available. Our results also indicated that location of the waist measurements is important and WU may be preferred site for determining negative risk factor regarding cholesterol in college-aged Hispanic males.

Medicine and Science in Sports and Exercise, May 1, 2018

Medicine and Science in Sports and Exercise, May 1, 2018

Medicine and Science in Sports and Exercise, May 1, 2017

Accumulated VO 2 during exercise was significantly lower in the HYP (P<0.001), whereas average RE... more Accumulated VO 2 during exercise was significantly lower in the HYP (P<0.001), whereas average RER values during exercise were significantly higher in the HYP than in the NOR (P<0.001). There was no significant difference between trials for any respiratory variables during post-exercise period. CONCLUSIONS: Repeated sprint exercise in hypoxia elicited blood lactate elevation compared with the same exercise in normoxia. However, magnitude of exercise-induced muscle damage response (elevation of serum Mb) was not affected.

Medicine and Science in Sports and Exercise, May 1, 2015

Clinical Physiology and Functional Imaging, Oct 17, 2019

Purpose The purpose of this study was to examine haemodynamic and arterial elasticity responses t... more Purpose The purpose of this study was to examine haemodynamic and arterial elasticity responses to aerobic exercise of varying durations. Methods Eighteen male subjects (age = 23Á4 AE 2Á0) performed a maximal aerobic fitness (VO 2max) test. Participants met in the laboratory following an overnight fast for three randomly assigned sessions. Assessments for large and small arterial elasticity (SAE), systemic vascular resistance (SVR), total vascular impedance (TVI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), pulse pressure (PP) and cardiac ejection time (CET) were performed using applanation tonometry at the radial artery. Following baseline measurements, participants executed aerobic exercise on a treadmill at 65% of their respective VO 2max for 30, 45 or 60 min on three different occasions. Postexercise measurements were performed immediately, 10, 20 and 40 min postexercise cessation. Results The 60-min exercise bout resulted in significantly increased SAE values (P < 0Á04) and decreased SVR values (P < 0Á02) when compared with the 30min exercise bout. The 60-min session also caused significantly higher HR values and significantly lower values for SV and DBP values following exercise (P < 0Á04). Conclusions The results of this study emphasize that varying the length of moderateintensity aerobic exercise bouts affects arterial elasticity response and total vascular resistance.

Journal of Sports Medicine and Physical Fitness, Jul 1, 2021

BACKGROUND To determine the effects of short-term low-intensity blood flow restriction (BFR) endu... more BACKGROUND To determine the effects of short-term low-intensity blood flow restriction (BFR) endurance training (ET) programs on measures of aerobic capacity, hemodynamics, and arterial stiffness in healthy young males. METHODS Thirty-nine healthy young recreationally active males participated in this short-term training study. They were randomly assigned to a high-intensity (HI; N=11; trained at 60 - 70% of VO2 reserve (VO2R)), low-intensity (LI; N=8; trained at 30-40% of VO2R), low-intensity with BFR (LI-BFR; N=10; trained at 30-40% of VO2R with BFR) or a non-exercising control group (N=10). The exercising subjects completed a 6-wk training protocol on a treadmill. Assessment of aerobic capacity (VO2max), hemodynamics and arterial stiffness were done before and after training. RESULTS Statistical analyses revealed a significant condition main effect (p< .05) for VO2max, indicating significant increase (p< .05) in VO2max in LI-BFR group compared to control. There were no significant changes for resting heart rate (RHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), carotid-radial pulse wave velocity (PWV), and carotid-femoral PWV (p> .05). However, femoral-tibial PWV decreased significantly (p< .05) from baseline to post-training. CONCLUSIONS The results indicate that the application of BFR during ET may cause faster and/or greater adaptations in one or more physiological systems resulting in improved cardiorespiratory fitness.

Exercise medicine (Online), Mar 12, 2018

This study examined the overweight, obesity, dietary habits, and physical activity among Hispanic... more This study examined the overweight, obesity, dietary habits, and physical activity among Hispanic college students. Methods: Eighty seven (n=87, age= 24.03 ± 5.69) Hispanic college students participated in the study. Descriptive and anthropometric measurements including resting heart rate (RHR), resting blood pressure (RBP), height, weight, body mass index (BMI), circumference measurements [waist at narrowest point (Xiphoid), and hip at widest point (Hip), body composition (BC) were collected. Subjects completed the Dietary Screener Questionnaire (DSQ). PA was estimated via Godin's (2011) Leisure-Time Exercise Questionnaire. Results: The mean BMI was 27.29±6.20 kg/m 2 , in the overweight range. The mean WC for males was 90.86±13.23 and for females was 82.35±14.61. Independent t-test showed that males had significantly higher values in height (p<0.01), weight (p<0.01), WC (p<0.01), and PA (p<0.01) compared to females. DSQ data indicated that participants consumed fruits, green leafy or lettuce salad, and milk less than recommended amount. It also showed high intake of sugary food. Conclusions: Hispanic young adults are in a poorest condition regarding the level of obesity as opposed to White and African American counterparts. This may be due to the decrease in PA. Diet behavior; less consumption of dairy, fruits and vegetable but frequent consumption of high sugary might be related to obesity in Hispanic young adults.

Medicine and Science in Sports and Exercise, Sep 1, 2022

Medicine and Science in Sports and Exercise, Aug 1, 2021

Medicine and Science in Sports and Exercise, Jul 1, 2020

The combination of Yoga with novel modalities like vibration platform and blood flow restriction ... more The combination of Yoga with novel modalities like vibration platform and blood flow restriction might exert enhanced physiological responses. PURPOSE: To investigate acute effects of yoga performed on a vibration platform (VP) with and without blood flow restriction (BFR) on hemodynamics, flexibility, and lower extremity explosive power. METHODS: Total 17 healthy subjects, 8 males (age= 22 ± 4.2 years) and 9 females (age= 24.2 ± 2.9 years), were screened by questionnaires, read and signed informed consent, and participated in the study. Subjects completed 4 separate randomized yoga sessions (on the floor, on the floor with BFR (FL+BFR), on the VP (VP), and on the VP with BFR (VP+BFR)) with at least 48-hr in between. The sessions involving BFR consisted of application of specialized cuffs on the uppermost portion of both thighs restricting blood flow. All sessions started with the measuring of resting heart rate (HR) and blood pressure (BP), followed by a 5-min treadmill warm-up session. Then vertical jump performance (VJ) and flexibility were assessed. The yoga sessions consisted of a series of 8 different yoga poses (Garland pose, Downward dog, Lunge, Chair pose, Twisted chair, Warrior, Squat and Lord of the dance), each lasting 30-sec with 1-min of rest in between poses. During each pose, breathing was monitored by using a metronome to prevent subjects from holding their breath during exercise. VJ and flexibility were again tested immediately post-exercise. HR and BP were also measured immediately after and every 5-min for 25-min following completion of the yoga session. RESULTS: Two-way ANOVA showed significant condition main effect (p<.05) for flexibility, indicating enhanced flexibility following VP compared to floor (p<.05) and VP+BFR (p<.05). Significant time main effects were detected for flexibility (p<.01), HR (p<.01), SBP (p<.01) and DBP (p<.01) indicating higher post-exercise values. CONCLUSION: Enhanced flexibility in response to yoga on VP can be attributed to a vibration-induced activation of Golgi tendon organ causing the related muscle to relax and desensitization of stretch reflex due to activation of muscle spindles by the rapid changes in muscle length. However, no significant improvements in flexibility following the VP+BFR session could be due the placement of BFR cuffs on the uppermost portion of thighs, interfering with vibration-induced muscle length alteration and excitation of Golgi tendon organs.

Medicine and Science in Sports and Exercise, Jul 1, 2020

PURPOSE: To determine the acute effects of different whole-body vibration (WBV) frequencies and s... more PURPOSE: To determine the acute effects of different whole-body vibration (WBV) frequencies and squat depths on lower extremity isometric and isokinetic muscle function and vertical jump performance. METHODS: Thirteen healthy male (age = 23.8 ± 5.3 years) and fifteen healthy female subjects (age = 22.45 ± 3.04 years) performed six randomized sessions of vibration protocols (VPs) in different squat positions with 90° (low-squat) and 140° (high-squat) knee flexion angle at 30 Hz (30Hz90°; 30Hz140°), 40 Hz (40Hz90°; 40Hz140°) & 50 Hz (50Hz90°; 50Hz140°). Each subject performed 5 sets x 1-min of static squats with 30-sec rest between each set. Then they rested for 5-min and repeated 5 more sets. Once completed, vertical jump performance was measured. Furthermore, subjects were tested for maximum 5-sec right knee extensor isometric contractions at 60° of knee flexion, and isokinetic concentric knee extension and flexion at 180°/sec, utilizing standard Biodex protocol. All VPs were performed on the same commercial side to side alternating vibration platform and foot placement for all squats was recorded to ensure consistency. RESULTS: Two-way repeated measures ANOVA indicated a significant condition main effect in average jump height (p<.01) and average jump time (p<.001), denoting enhanced jump performance following 40Hz140° (p<.05) and 50Hz140° (p<.01) compared to 50Hz90°. A significant condition main effect was found in peak-torque during the isokinetic test, where observed changes were greater for both 30Hz140° and 40Hz140° compared to 30Hz90° (p<.05) and 50Hz90° (p<.01). Lastly, the best performance on peak-torque during the isometric test was significantly higher after 30Hz140° (p<.05) and 40Hz140° (p≤.05) compared to 50Hz90°. CONCLUSION: The findings are suggestive of greater muscular strength and explosive power production following a high-squat WBV warm-up compared to low-squat WBV warm-up. This can be attributed to augmented muscle fatigue and/or increased muscle length due to the plasticity of skeletal muscle while performing low-squat WBV warm-up, resulting in impaired ability to produce muscular force.

International journal of aquatic research and education, Jul 1, 2018

Available research clearly shows that more children who have disabilities, including those with s... more Available research clearly shows that more children who have disabilities, including those with severe disabilities, are participating in swimming programs as well as wanting to be taught in a regular aquatic class without being segregated. Aquatic instructors need to prepare lessons that include children both with and without disabilities. This means that aquatics instructors need to understand and be willing to implement unique teaching and managerial techniques that foster the safe and successful learning environment for all children. While the task of teaching children who have severe disabilities may seem difficult at first, with a little knowledge and experience, instructors can become better teachers to all children, gain confidence in their instructional skills, and see more positive and successful performances in their aquatic programs.

Clinical Physiology and Functional Imaging, Apr 4, 2018

The aim of this study was to assess the effect of isometric exercises performed during whole-body... more The aim of this study was to assess the effect of isometric exercises performed during whole-body vibration (WBV) with and without blood flow restriction (BFR) on arterial elasticity and hemodynamic variables. Methods: Eight male subjects performed static upper body (UB) and lower body (LB) exercises on a vibration platform with and without BFR. During BFR sessions, BFR cuffs were placed on the arms or legs and inflated to a target pressure. Exercises consisted of eight 45-s sets for UB, and ten 1-min sets for LB. Arterial elasticity and hemodynamic variables were assessed before, at 10 min and 40 min postexercise. Repeated measures ANOVA was used to test the mean differences in related variables. Results: A significant condition (BFR versus no-BFR) main effect was detected for small arterial elasticity (P<0Á05). For heart rate (HR), there were significant time (P<0Á01), condition (P = 0Á02) and body (P = 0Á04) main effects during exercise and condition (P<0Á04) and time (P<0Á01) main effects following exercise. Significantly lower values in systemic vascular resistance were detected at 10 min post compared to 40 min post (P<0Á02) and UB compared to LB (P = 0Á02). Conclusions: Results showed that small arteries stayed stiffer for a longer period of time after vibration exercises with BFR and BFR placed a greater demand on cardiovascular system. Findings also indicated that the type of exercises performed and/or the measurement location are very important and should be taken into account when examining arterial response.

Medicine and Science in Sports and Exercise, Jul 1, 2020

Medicine and Science in Sports and Exercise, May 1, 2017

The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) mu... more The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) muscle as measured by electromyography (EMG) following short-term resistance training with and without blood flow restriction (BFR). METHODS: 12 males (age = 27.4 ± 6.3 years; height = 171 ± 7 cm; weight = 79.8 ± 13.2 kg) performed six sessions of lower body unilateral resistance training using a leg extension machine. The leg on which BFR was applied was determined through randomization leg dominance Each training session consisted of unilateral knee extensions with and without blood flow restriction. Electromyography data was recorded for each participant during two isometric maximum voluntary contractions (MVC) and two isokinetic knee extension tests (180°/s and 60°/s) using a Biodex System 4 Pro™. EMG was recorded from the RF during these tests. Resistance training consisted of six non-consecutive sessions of knee extension exercises performed in a time frame of two weeks. For the BFR group, subjects trained for a total of four sets (30, 15, 15, 15) at an intensity of 20% 1RM. The contralateral limb was trained with two sets of 11 repetitions at an intensity of 70% 1RM without BFR. The volume of exercises was similar for both conditions. RESULTS: No condition*time interactions or condition and time main effects were observed for root mean square (RMS), mean RMS, yMax, and median frequency (MDF) in both MVC and isokinetic 180°/s and 60°/s (p>0.05). CONCLUSIONS: Both training conditions resulted in insignificant changes and there was no significant difference found between time points. It could be concluded that this was not enough time or stimulus to note major differences across modalities in relation to neuromuscular adaptations of the RF as measured by EMG. Further studies should investigate the effects of higher volume load on neuromuscular adaptations.

International Journal of Exercise Science: Conference Proceedings, 2017

The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) mu... more The purpose of the study was to determine the neuromuscular changes in the rectus femoris (RF) muscle as measured by electromyography (EMG) following short-term resistance training with and without blood flow restriction (BFR). METHODS: 12 males (age = 27.4 ± 6.3 years; height = 171 ± 7 cm; weight = 79.8 ± 13.2 kg) performed six sessions of lower body unilateral resistance training using a leg extension machine. The leg on which BFR was applied was determined through randomization leg dominance Each training session consisted of unilateral knee extensions with and without blood flow restriction. Electromyography data was recorded for each participant during two isometric maximum voluntary contractions (MVC) and two isokinetic knee extension tests (180°/s and 60°/s) using a Biodex System 4 Pro™. EMG was recorded from the RF during these tests. Resistance training consisted of six non-consecutive sessions of knee extension exercises performed in a time frame of two weeks. For the BFR group, subjects trained for a total of four sets (30, 15, 15, 15) at an intensity of 20% 1RM. The contralateral limb was trained with two sets of 11 repetitions at an intensity of 70% 1RM without BFR. The volume of exercises was similar for both conditions. RESULTS: No condition*time interactions or condition and time main effects were observed for root mean square (RMS), mean RMS, yMax, and median frequency (MDF) in both MVC and isokinetic 180°/s and 60°/s (p>0.05). CONCLUSIONS: Both training conditions resulted in insignificant changes and there was no significant difference found between time points. It could be concluded that this was not enough time or stimulus to note major differences across modalities in relation to neuromuscular adaptations of the RF as measured by EMG. Further studies should investigate the effects of higher volume load on neuromuscular adaptations.

Medicine and Science in Sports and Exercise, Jun 1, 2019

To determine the effects of guideline recommended hypertrophy and blood flow restriction training... more To determine the effects of guideline recommended hypertrophy and blood flow restriction training protocols on pulse wave velocity in recreationally active males. METHODS: Fourteen male subjects (age= 23.7±2.6) were randomly assigned to one of two groups that trained the knee flexors, extensors, and split squat for 6 weeks. The two training groups included: a blood flow restriction group (BFR, N=8) and hypertrophy (HYP, N=6). All training groups began with subjects warming up on the cycle ergometer at 50 rpm with 2.0 kg resistance and subjects were then lead through the resistance training programs that remained constant for each session thereafter. The HYP group followed NSCA guideline for recommended intensity, set, and rest period. The HYP group performed exercise for 4 sets of 10 repetitions 3x/wk at 75% of 1RM with 90 second rest between each set. The BFR group performed exercises for 4 sets of 30, 15, 15, 15 reps 3x/wk at 40% of 1RM with 30 second rest between each set. Each training session was monitored by a trained individual to make sure the correct breathing pattern were maintained during lifts to avoid the Valsalva maneuver. As for pre and post testing sessions, fasted subjects (for at least 8 hours) reported to the lab and hydration level was assessed by clinical urine refractometer before testing sessions. PWV was measured non-invasively using applanation tonometry, in which a probe was used on the surface of the skin over the carotid, radial, femoral, and pedal arteries to obtain segmental measures. RESULTS: One-way ANOVA found no between-group differences in any of the outcome measures of interest at baseline. There were no significant condition main effects for carotid-radial (CR), carotid-femoral (CF), femoral-distal (FD), however a significant time main effect was detected for CF (p < 0.05). CF-PWV significantly decreased from baseline to post testing. CONCLUSIONS: The findings of the study suggest that both BFR and HYP training programs are similarly effective in decreasing the central arterial stiffness. The data also indicates that avoiding the Valsalva maneuver may be necessary for positive changes in aortic stiffness and BFR training protocol can be used an alternative method for those who can't or do not want to lift high loads to improve central arterial elasticity.

Medicine and Science in Sports and Exercise, May 1, 2016

High-intensity functional training (HIFT) is a relatively new mode of training that is gaining po... more High-intensity functional training (HIFT) is a relatively new mode of training that is gaining popularity among the general population. A recognized form of HIFT is CrossFit™, which is defined as a program of "constantly varied, high-intensity, functional movements." Although there are purported improvements in strength and body composition with this training modality, there is a lack of empirical evidence to support these claims. PURPOSE: The purpose of this study was to examine changes in body composition and strength among apparently healthy individuals following 16-weeks of HIFT. METHODS: 53 individuals originally signed up for the study. Testing sessions included pre and post measures for body composition (Dual-Energy X-Ray Absorptiometry) and strength (5RM Front squat). Training included participation in HIFT a minimum of twice a week for 16-weeks. RESULTS: 26 individuals (49%) completed the 16-week program and provided all required measures. Repeated measures analysis of variance revealed no gender effect on strength or body composition outcomes. Paired-sample t-tests showed significant improvements in the front squat (Males

Medicine and Science in Sports and Exercise, May 1, 2016

The aim of the study was to assess the effect of dynamic upper and lower body vibration exercises... more The aim of the study was to assess the effect of dynamic upper and lower body vibration exercises with blood flow restriction (BFR) on arterial elasticity and hemodynamic variables. METHODS: Seventeen male subjects (age= 23.8±24.9) performed dynamic push-up (PU) or squat (SQ) exercises on a vibration platform set at 30 Hz with and without BFR. During BFR sessions, BFR cuffs were inflated to a pressure of 100 mmHg for PU and to a pressure determined by multiplying the arm systolic blood pressure by 1.44 for SQ. Exercises consisted of eight 45s sets for PU, and for ten 1min sets for SQ. Arterial elasticity and hemodynamic variables were assessed before by non-invasive methods using the radial artery tonometer, at 10min, 20min, and 40min post-exercise. RESULTS: There were significant body*time interaction (p< 0.02) and main effects for body (SQ vs. PU) (p< 0.04) and time (p<0.01) for large arterial elasticity. There was also a body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.01) for vascular resistance. There was a significant time main effect for systolic blood pressure, but a body*time interaction (p<0.01) and time main effect (p<0.01) were detected for diastolic blood pressure. There were significant body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.05) for pulse pressure. There were significant body*time interaction (p< 0.01) and main effects for condition (p< 0.03), body (p< 0.01), and time (p<0.01) for pulse rate. Significant main effects for condition (p< 0.04) and time (p<0.01) were detected for cardiac ejection time. There were significant body*time interaction (p< 0.01) and time main effect (p< 0.01) for stroke volume. There was also a body*time interaction (p< 0.01) and main effects for body (p< 0.01) and time (p<0.01) for cardiac output. CONCLUSION: Combining dynamic vibration exercise with BFR changed the pattern and the level of changes in pulse rate and cardiac ejection time, which could be explained due to lower venous return. The responses in several variables were greater following PU indicating that the importance of type of exercise performed and/or the site of measurement taken. Future studies should investigate acute and chronic effects of different type and intensity of BFR exercises with vibration on arterial compliance.

Medicine and Science in Sports and Exercise, May 1, 2016

PURPOSE: To investigate the relationship between anthropometric measures, blood pressure (BP), to... more PURPOSE: To investigate the relationship between anthropometric measures, blood pressure (BP), total cholesterol (TC), fasting blood glucose (FBG), and high density lipoprotein cholesterol (HDL) among Hispanic college-aged males 18 to 30 in the Lower Rio Grande Valley. METHODS: Thirty-five male subjects (age= 23.2 ± 2.8) read and signed the informed consent prior to participation in this study. Subjects had their height, weight, and three circumference measurements taken [waist at umbilicus (WU), waist at smallest point (WSP), and hip at widest point (HWP)] and their body mass index (BMI) calculated. A fasting blood sample was taken to analyze TC, HDL, and FBG; in addition, TC:HDL ratio and non-HDL were calculated. Percent body fat (BF) was also measured using air displacement plethysmography. RESULTS: Age was found to be significantly correlated with weight (r= 0.491, p< 0.01), BF (r= 0.575, p< 0.01), BMI (r= 0.539, p< 0.01), diastolic (DBP) (r= 0.427, p< 0.01), WSP (r= 0.596, p< 0.01), WU (r= 0.638, p< 0.01), and HWP (r= 0.485, p< 0.01), and non-HDL (r= 0.405, p< 0.02). BF and BMI were significantly correlated with HDL (r= −0.370, p< 0.03; r= −0.384, p< 0.03) and correlated with TC:HDL ratio (r= 0.466, p< 0.01; r= 0.441, p< 0.01). WSP, WU, and HWP were significantly correlated with TC:HDL ratio (r= 0.429, p< 0.01; r= 0.449, p< 0.01; r= 0.372, p< 0.03), while only the WU and HWP circumference measurements were significantly correlated with HDL cholesterol (r= −0.369, p< 0.03; r= −0.428, p< 0.01). CONCLUSIONS: The results indicated age had notable correlations across most measures, even within this small 12-year range, which may be due to a decrease in physical activity throughout the college career. The data indicated higher BMI and BF were similarly correlated with lower HDL blood concentration and an increased TC:HDL ratio. This suggests that BMI is still a strong predictor of cholesterol level and can be relied upon when body composition analyzation is not available. Our results also indicated that location of the waist measurements is important and WU may be preferred site for determining negative risk factor regarding cholesterol in college-aged Hispanic males.

Medicine and Science in Sports and Exercise, May 1, 2018

Medicine and Science in Sports and Exercise, May 1, 2018

Medicine and Science in Sports and Exercise, May 1, 2017

Accumulated VO 2 during exercise was significantly lower in the HYP (P<0.001), whereas average RE... more Accumulated VO 2 during exercise was significantly lower in the HYP (P<0.001), whereas average RER values during exercise were significantly higher in the HYP than in the NOR (P<0.001). There was no significant difference between trials for any respiratory variables during post-exercise period. CONCLUSIONS: Repeated sprint exercise in hypoxia elicited blood lactate elevation compared with the same exercise in normoxia. However, magnitude of exercise-induced muscle damage response (elevation of serum Mb) was not affected.

Medicine and Science in Sports and Exercise, May 1, 2015

Clinical Physiology and Functional Imaging, Oct 17, 2019

Purpose The purpose of this study was to examine haemodynamic and arterial elasticity responses t... more Purpose The purpose of this study was to examine haemodynamic and arterial elasticity responses to aerobic exercise of varying durations. Methods Eighteen male subjects (age = 23Á4 AE 2Á0) performed a maximal aerobic fitness (VO 2max) test. Participants met in the laboratory following an overnight fast for three randomly assigned sessions. Assessments for large and small arterial elasticity (SAE), systemic vascular resistance (SVR), total vascular impedance (TVI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), pulse pressure (PP) and cardiac ejection time (CET) were performed using applanation tonometry at the radial artery. Following baseline measurements, participants executed aerobic exercise on a treadmill at 65% of their respective VO 2max for 30, 45 or 60 min on three different occasions. Postexercise measurements were performed immediately, 10, 20 and 40 min postexercise cessation. Results The 60-min exercise bout resulted in significantly increased SAE values (P < 0Á04) and decreased SVR values (P < 0Á02) when compared with the 30min exercise bout. The 60-min session also caused significantly higher HR values and significantly lower values for SV and DBP values following exercise (P < 0Á04). Conclusions The results of this study emphasize that varying the length of moderateintensity aerobic exercise bouts affects arterial elasticity response and total vascular resistance.

Journal of Sports Medicine and Physical Fitness, Jul 1, 2021

BACKGROUND To determine the effects of short-term low-intensity blood flow restriction (BFR) endu... more BACKGROUND To determine the effects of short-term low-intensity blood flow restriction (BFR) endurance training (ET) programs on measures of aerobic capacity, hemodynamics, and arterial stiffness in healthy young males. METHODS Thirty-nine healthy young recreationally active males participated in this short-term training study. They were randomly assigned to a high-intensity (HI; N=11; trained at 60 - 70% of VO2 reserve (VO2R)), low-intensity (LI; N=8; trained at 30-40% of VO2R), low-intensity with BFR (LI-BFR; N=10; trained at 30-40% of VO2R with BFR) or a non-exercising control group (N=10). The exercising subjects completed a 6-wk training protocol on a treadmill. Assessment of aerobic capacity (VO2max), hemodynamics and arterial stiffness were done before and after training. RESULTS Statistical analyses revealed a significant condition main effect (p< .05) for VO2max, indicating significant increase (p< .05) in VO2max in LI-BFR group compared to control. There were no significant changes for resting heart rate (RHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), carotid-radial pulse wave velocity (PWV), and carotid-femoral PWV (p> .05). However, femoral-tibial PWV decreased significantly (p< .05) from baseline to post-training. CONCLUSIONS The results indicate that the application of BFR during ET may cause faster and/or greater adaptations in one or more physiological systems resulting in improved cardiorespiratory fitness.

Exercise medicine (Online), Mar 12, 2018

This study examined the overweight, obesity, dietary habits, and physical activity among Hispanic... more This study examined the overweight, obesity, dietary habits, and physical activity among Hispanic college students. Methods: Eighty seven (n=87, age= 24.03 ± 5.69) Hispanic college students participated in the study. Descriptive and anthropometric measurements including resting heart rate (RHR), resting blood pressure (RBP), height, weight, body mass index (BMI), circumference measurements [waist at narrowest point (Xiphoid), and hip at widest point (Hip), body composition (BC) were collected. Subjects completed the Dietary Screener Questionnaire (DSQ). PA was estimated via Godin's (2011) Leisure-Time Exercise Questionnaire. Results: The mean BMI was 27.29±6.20 kg/m 2 , in the overweight range. The mean WC for males was 90.86±13.23 and for females was 82.35±14.61. Independent t-test showed that males had significantly higher values in height (p<0.01), weight (p<0.01), WC (p<0.01), and PA (p<0.01) compared to females. DSQ data indicated that participants consumed fruits, green leafy or lettuce salad, and milk less than recommended amount. It also showed high intake of sugary food. Conclusions: Hispanic young adults are in a poorest condition regarding the level of obesity as opposed to White and African American counterparts. This may be due to the decrease in PA. Diet behavior; less consumption of dairy, fruits and vegetable but frequent consumption of high sugary might be related to obesity in Hispanic young adults.

Medicine and Science in Sports and Exercise, Sep 1, 2022

Medicine and Science in Sports and Exercise, Aug 1, 2021

Medicine and Science in Sports and Exercise, Jul 1, 2020

The combination of Yoga with novel modalities like vibration platform and blood flow restriction ... more The combination of Yoga with novel modalities like vibration platform and blood flow restriction might exert enhanced physiological responses. PURPOSE: To investigate acute effects of yoga performed on a vibration platform (VP) with and without blood flow restriction (BFR) on hemodynamics, flexibility, and lower extremity explosive power. METHODS: Total 17 healthy subjects, 8 males (age= 22 ± 4.2 years) and 9 females (age= 24.2 ± 2.9 years), were screened by questionnaires, read and signed informed consent, and participated in the study. Subjects completed 4 separate randomized yoga sessions (on the floor, on the floor with BFR (FL+BFR), on the VP (VP), and on the VP with BFR (VP+BFR)) with at least 48-hr in between. The sessions involving BFR consisted of application of specialized cuffs on the uppermost portion of both thighs restricting blood flow. All sessions started with the measuring of resting heart rate (HR) and blood pressure (BP), followed by a 5-min treadmill warm-up session. Then vertical jump performance (VJ) and flexibility were assessed. The yoga sessions consisted of a series of 8 different yoga poses (Garland pose, Downward dog, Lunge, Chair pose, Twisted chair, Warrior, Squat and Lord of the dance), each lasting 30-sec with 1-min of rest in between poses. During each pose, breathing was monitored by using a metronome to prevent subjects from holding their breath during exercise. VJ and flexibility were again tested immediately post-exercise. HR and BP were also measured immediately after and every 5-min for 25-min following completion of the yoga session. RESULTS: Two-way ANOVA showed significant condition main effect (p<.05) for flexibility, indicating enhanced flexibility following VP compared to floor (p<.05) and VP+BFR (p<.05). Significant time main effects were detected for flexibility (p<.01), HR (p<.01), SBP (p<.01) and DBP (p<.01) indicating higher post-exercise values. CONCLUSION: Enhanced flexibility in response to yoga on VP can be attributed to a vibration-induced activation of Golgi tendon organ causing the related muscle to relax and desensitization of stretch reflex due to activation of muscle spindles by the rapid changes in muscle length. However, no significant improvements in flexibility following the VP+BFR session could be due the placement of BFR cuffs on the uppermost portion of thighs, interfering with vibration-induced muscle length alteration and excitation of Golgi tendon organs.

Medicine and Science in Sports and Exercise, Jul 1, 2020

PURPOSE: To determine the acute effects of different whole-body vibration (WBV) frequencies and s... more PURPOSE: To determine the acute effects of different whole-body vibration (WBV) frequencies and squat depths on lower extremity isometric and isokinetic muscle function and vertical jump performance. METHODS: Thirteen healthy male (age = 23.8 ± 5.3 years) and fifteen healthy female subjects (age = 22.45 ± 3.04 years) performed six randomized sessions of vibration protocols (VPs) in different squat positions with 90° (low-squat) and 140° (high-squat) knee flexion angle at 30 Hz (30Hz90°; 30Hz140°), 40 Hz (40Hz90°; 40Hz140°) & 50 Hz (50Hz90°; 50Hz140°). Each subject performed 5 sets x 1-min of static squats with 30-sec rest between each set. Then they rested for 5-min and repeated 5 more sets. Once completed, vertical jump performance was measured. Furthermore, subjects were tested for maximum 5-sec right knee extensor isometric contractions at 60° of knee flexion, and isokinetic concentric knee extension and flexion at 180°/sec, utilizing standard Biodex protocol. All VPs were performed on the same commercial side to side alternating vibration platform and foot placement for all squats was recorded to ensure consistency. RESULTS: Two-way repeated measures ANOVA indicated a significant condition main effect in average jump height (p<.01) and average jump time (p<.001), denoting enhanced jump performance following 40Hz140° (p<.05) and 50Hz140° (p<.01) compared to 50Hz90°. A significant condition main effect was found in peak-torque during the isokinetic test, where observed changes were greater for both 30Hz140° and 40Hz140° compared to 30Hz90° (p<.05) and 50Hz90° (p<.01). Lastly, the best performance on peak-torque during the isometric test was significantly higher after 30Hz140° (p<.05) and 40Hz140° (p≤.05) compared to 50Hz90°. CONCLUSION: The findings are suggestive of greater muscular strength and explosive power production following a high-squat WBV warm-up compared to low-squat WBV warm-up. This can be attributed to augmented muscle fatigue and/or increased muscle length due to the plasticity of skeletal muscle while performing low-squat WBV warm-up, resulting in impaired ability to produce muscular force.