Physiology Commons^™

Vitamin D Deficiency In Tamu Female Basketball Players And Supplement Effectiveness, Melissa Bellows, Jon Tanguay, Stephen F. Crouse, Diana Harbourt

International Journal of Exercise Science: Conference Proceedings

Purpose:

Vitamin D deficiency has been defined by the Institute of Medicine (IOM) as a level of serum 25-OH vitamin D less than 20 ng/mL. The Endocrine Society went on to further define vitamin D insufficiency as a level between 21 and 29 ng/mL. Research suggests that vitamin D deficiency could increase fracture risk in athletes, especially females who are naturally prone to deficiency.

Methods: Eight female athletes from the Texas A&M women’s basketball team

(21 ± 1yrs; 88 ± 18 kg; 179 ± 16.5cm; BMI 26 ± 3 kg/m²; black female) were identified to have low vitamin …

Cardiorespiratory And Biomechanical Responses To Simulated Horseback Riding In Healthy Children, Brandon R. Rigby, Zacharias Papadakis, Annie Bane, Jin Park, Peter Grandjean

International Journal of Exercise Science: Conference Proceedings

TACSM Abstract

Cardiorespiratory and biomechanical responses to simulated horseback riding in healthy children

B RHETT RIGBY, ZACHARIAS PAPADAKIS, ANNIE A BANE, JIN K PARK, and PETER W GRANDJEAN

Baylor Laboratories for Exercise Science and Technology; Department of Health, Human Performance, and Recreation; Baylor University; Waco, TX

Category: Doctoral

ABSTRACT

The movement of specific body segments during horseback riding is similar to common physical activities such as walking. Yet, little is known regarding the cardiovascular responses to horseback riding (HBR) which may be due to how difficult it is to quantify the physical work of HBR. The purpose of this study …

High On Grass? Influence Of Terrain On Human Walking Economy., Lindsay M. Wohlers, Kenneth P. Clark, Laurence J. Ryan, Peter G. Weyand

International Journal of Exercise Science: Conference Proceedings

Introduction: The metabolic energy cost of human walking has been extensively studied. However, the influence of terrain on the metabolic costs incurred across commonly encountered surfaces is not well understood. Objective: Our objective was to test whether the metabolic cost of walking would vary between treadmill, asphalt, and grass surfaces. We hypothesized that the metabolic energy cost of walking would not differ between the three common level walking conditions: (standard) commercial treadmill, firm asphalt and well-groomed grass field. Methods: Five subjects walked on a level treadmill at speeds ranging from 0.4 m·s^-1 to 1.9 m·s^-1. Indirect calorimetry …

Human Sprint Running Mechanics: Do Right And Left Legs Apply Equal Ground Forces?, Kenneth P. Clark, Laurence J. Ryan, Peter G. Weyand

International Journal of Exercise Science: Conference Proceedings

Introduction: A growing body of research has focused on between-leg asymmetry as a critical factor for athletic performance and dysfunction. Specifically, various measures of between-leg asymmetry during running have been investigated in both healthy and injured populations. However, while the most important factor for running performance is the magnitude and rate of ground force application, it is not known whether the right and left legs typically apply equal ground forces at faster running speeds. Objective: In a healthy population of athletic female participants, we aimed to: 1) compare the mechanics of ground force application between right and left legs during …

Skin And Cerebral Vascular Function / Reactivity In Healthy Young Adult African Americans, Kiyoung Kim

International Journal of Exercise Science: Conference Proceedings

African Americans (AA) are at an increased risk for cardio and cerebral vascular disease relative to Caucasians (CA) and the underlying impairments manifest as early as the second generation prior to overt signs of risk. The mechanisms of this increased risk are multifactorial; however, evidence suggests that microvascular dysfunction is a primary contributor. This study tested the hypothesis that microvascular function, indexed by the skin vascular conductance (SkVc) response to local heating, is impaired in young otherwise healthy AAs. Furthermore, we hypothesized that AAs have an attenuated cerebral vasodilator response to hypercapnia. To date complete data sets have has been …

Cerebrovascular Hemodynamics During Concentric And Eccentric Phases Of Heavy Resistance Exercise, Gilbert Moralez, Steven A. Romero, Caroline A. Rickards, Peter B. Raven, William H. Cooke

International Journal of Exercise Science: Conference Proceedings

Rapid and drastic fluctuations in arterial blood pressures, such as those occurring during heavy resistance exercise pose a unique challenge to the maintenance of cerebral perfusion. During high-intensity leg cycling, regulation of cerebral perfusion is reduced by rapid decreases in beat-to-beat fluctuations in blood pressure (diastolic phase) rather than rapid increases (systolic phase). The purpose of this study was to test the hypothesis that rhythmic heavy resistance exercise will similarly impair the regulation of cerebral blood flow during the diastolic phase of beat-to-beat fluctuations in pressure. We studied seven healthy male subjects. Beat-to-beat finger arterial pressures, and middle cerebral artery …

Vasodilation To Pth 1-84 In Bone Resistance Arteries Of Rats Occurs Via Endothelium-Dependent, Rather Than Endothelium-Independent Signaling, Tyler J. Benson, Rhonda D. Prisby

International Journal of Exercise Science: Conference Proceedings

Parathyroid hormone (PTH) is a potent vasodilator, causing systemic hypotension. Previous investigations concluded that vasodilation to PTH in a variety of vascular beds occurs via inhibition of L-type calcium channels in smooth muscle cells. Further, removal of the endothelium in aortic strips and tail arteries did not inhibit relaxation to PTH, suggesting that vasodilation in these vessels does not require nitric oxide (NO) or vascular endothelial cells (Pang et al., 1985; Nickols 1987; Nickols et al., 1986; Crass et al., 1988). We have previously shown that PTH 1-84 augments vasodilation to ~52% of maximum diameter in the femoral principal nutrient …

Comparing Three Methods Of Measuring Skin Temperature During Exercise In A Hot, Humid Environment, Randall R. Williams, Adam S. Venable, Brian K. Mcfarlin

International Journal of Exercise Science: Conference Proceedings

Exercise in a hot, humid environment substantially increases the physiological stress of exercise. Most of the techniques that are currently used to monitor changes in skin temperature have been in use for more than 20 years with little innovation. The purpose of the present study was two-fold: 1) to compare three techniques for measuring skin temperature (wired skin electrode, wireless temperature data logger, and thermal imaging) and 2) to compare and contrast these measures in men and women completing 45-min of cycling in a hot (39±2°C), humid (45±5% RH) environment. The CPHS committee approved all procedures described in this report …

Effects Of Capsaicin And Evodiamine Ingestion On Energy Expenditure And Fat Oxidation At Rest And After Moderately-Intense Exercise In Young Men, Neil A. Schwarz, Mike Spillane, Paul La Bounty, Pete Grandjean, Brian Leutholtz, Darryn S. Willoughby

International Journal of Exercise Science: Conference Proceedings

Capsaicin and evodiamine are two thermogenic agents each recognized for their ability to stimulate the sympathetic nervous system and are thus found in many dietary supplements. Therefore, the purpose of this study was to observe the effects that capsaicin and evodiamine have on hemodynamics, energy expenditure, and markers of lipid oxidation while at rest and after a single bout of moderate-intensity exercise in young men. In a randomized, cross-over design, 11 men orally ingested 500 mg of capsaicin, evodiamine, or placebo while at rest after 30 minutes of resting energy expenditure assessment using open-circuit spirometry. After an additional 30 minutes …

Association Of Cardiovascular Fitness And Metabolic Syndrome In Male Police Officers, Matthew S. Schmidt, Steve Martin

International Journal of Exercise Science: Conference Proceedings

Metabolic syndrome has been shown in numerous studies to be related to a higher incidence of coronary artery disease (CAD). A study by Jurca and coworkers (Med. Sci. Sports Exerc 36(8):1301-1307, 2004) found a relationship between aerobic fitness and the prevalence of metabolic syndrome in a group of men enrolled in the Aerobics Center Longitudinal Study (ACLS). In addition, recent work in our lab (Int J Exerc Sci 2(1): S43, 2009) has supported these findings. However, research exploring this relationship is still lacking in male police officers. Previous research has suggested that the prevalence of CAD in police …

Gender Differences In Skin And Core Body Temperature During Exercise In A Hot, Humid Environment., Adam S. Venable, Randall R. Williams, Brian K. Mcfarlin

International Journal of Exercise Science: Conference Proceedings

Background. It is universally accepted that men and women regulate heat differently during exercise in hot, humid environments. Despite this common knowledge, little empirical data is available to explain how gender differences effect core/skin temperature changes. Further, the data that is available includes only limited measurement sites and/or time points. Methods. The purpose of this study was to measure the heat regulatory patterns for both men and women during 60-min of exercise in a hot, humid environment. Twenty aerobically fit subjects (10 men; 10 women) completed an acclimation session followed by a 60-min exercise protocol in an environmental chamber set …

Association Of Cardiovascular Fitness And Syndrome X In Male Firefighters, Adam C. Sanchez, Steven E. Martin, Brad S. Lambert, Alex Carradine, John S. Green Facsm, Steve F. Crouse Facsm

International Journal of Exercise Science: Conference Proceedings

Metabolic syndrome has been shown in numerous studies to be related to a higher incidence of coronary artery disease. A study by Jurca and coworkers (Med. Sci. Sports Exerc 36(8):1301-1307, 2004) found a relationship between cardiovascular fitness and the prevalence of metabolic syndrome in a group of men enrolled in the Aerobics Center Longitudinal Study (ACLS). In addition, recent work in our lab (Int J Exerc Sci 2(1): S43, 2009) has supported these findings. However, research exploring this relationship is still lacking in male firefighters, whose leading cause of line-of-duty deaths is heart attacks. Purpose: To further …

Deptor Expression Correlates With Muscle Protein Synthesis, Kevin L. Shimkus, Elyse V. Wudeck, Yasaman Shirazi-Fard, Mats I. Nilsson, Nicholas P. Greene, Harry A. Hogan, James D. Fluckey

International Journal of Exercise Science: Conference Proceedings

Mammalian target of rapamycin (mTOR) has long been declared a focal point of muscle protein synthesis. mTORC1 (an mTOR complex consisting of mTOR, raptor, PRAS40, and mLST8) has been associated with regulation of protein translation in muscle, altering expression and activity levels of key downstream targets S6K1 and eIF-4E-BP1. mTORC1 has been shown to be affected by various stimuli, including nutritional status, growth factors, and mechanical loading. But in past incidents we have found disconnects in muscle protein synthesis and mTOR signaling, stimulating discussions that mTOR content and activation alone may not be able to fully account for muscle protein …

Accuracy Of Various Newer Pedometers Placed At Different Body Sites, Victor Lee, Wonil Park, Byungmo Ku, Hirofumi Tanaka

International Journal of Exercise Science: Conference Proceedings

Introduction: Pedometers are increasingly used as a self-monitoring aid for achieving and increasing daily physical activity. Older pedometers had varied levels of accuracy ranging from 0 to 45% difference and were needed to be positioned in a certain way (on the waist). Newer models can be placed anywhere on the body but its accuracy is unknown when they are placed at different bodily sites. Purpose: We determined the accuracy of various newer pedometers under controlled laboratory and free walking conditions. Method: A total of 40 subjects (20 male and 20 female) varying widely in age (18-61 years) and BMI (18-38 …

Transiently Silencing Genes Associated With Voluntary Physical Activity Using Intravenous Injection Of Vivo‐Morpholinos, David P. Ferguson, Emily E. Schmidt, Dr.Timothy Lightfoot

International Journal of Exercise Science: Conference Proceedings

Physical inactivity has been associated with several diseases and conditions with multiple candidate genes proposed to regulate voluntary physical activity. However, there has not been a reliable method to silence candidate genes in vivo to determine causal mechanisms of physical activity regulation. The novel molecular biology tool, Vivo‐morpholinos, is a potential method to transiently silence specific genes. Thus, the aim of this study was to validate the use of Vivo‐morpholinos in a mouse model for voluntary physical activity with several sub‐objectives. We observed that Vivomorpholinos achieved between 60 – 97% knockdown of Drd1‐, Vmat2‐, and Glut4‐protein in skeletal muscle, the …

Aquatic Treadmill Training Reduces Blood Pressure Reactivity To Acute Graded Exercise In Previously Sedentary Adults, Brad S. Lambert, Nicholas P. Greene, Dustin P. Joubert, Steven E. Riechman, James D. Fluckey, Stephen F. Crouse, Alex T. Carradine

International Journal of Exercise Science: Conference Proceedings

Endurance exercise may reduce blood pressure and improve vasodilatory capacity thereby blunting the hypertensive response to stress. To test the efficacy of a novel model of low-impact endurance training, the aquatic-based treadmill (ATM), to improve blood pressure parameters, we recruited 60 sedentary adults and randomized to 12-weeks of either ATM (n = 36 [19 men, 17 women] , 41±2 yr, 173.58 ±1.58cm, 93.19 ±3.15kg) or land-based treadmill (LTM, n = 24 [11 men, 13 women], 42 ±2yr, 170.39 ±1.94cm, 88.14 ±3.6kg) training; 3sessions·wk-1, progressing to 500 kcal·session-1, 85% VO2max. The maximal Bruce treadmill test protocol was performed before and after …

Inter-Individual Differences In Tolerance To A Simulated Hemorrhage Challenge During Heat Stress: Cerebrovascular Control, Joshua F. Lee, Kevin M. Christmas, Chansol Hurr, Kiyoung Kim, R. Matthew Brothers, Michelle L. Harrison

International Journal of Exercise Science: Conference Proceedings

A high degree of inter-individual variability exists in heat stress (HS) -induced reductions in orthostatic tolerance relative to normothermia (NT), which may be associated with HS-mediated reductions in cerebral perfusion, and thus mechanisms of cerebrovascular control during hypotensive challenges. This study tested two hypotheses; 1) the magnitude of increase in cerebral autoregulation (CA) would be negatively correlated with the difference in tolerance to graded lower body negative pressure (LBNP) 30 [assessed with a cumulative stress index (CSI)] during HS relative to NT (CSIdiff), and 2) cerebrovascular sensitivity to HS-induced hypocapnia would be positively correlated with CSIdiff. Subjects (N=13) were exposed …

Eating And Exercise Behaviors, And Motivational Differences Between Kinesiology Majors And Non-Majors, Elizabeth L. Haddock, Stacey A. Gaines

International Journal of Exercise Science: Conference Proceedings

Eating and exercise behaviors have garnered a substantial amount of research attention. Several health risks are known to be lower in individuals who exercise, yet only 35% of college students exercise on a regular basis (Silliman, Rodas-Fortier, & Neyman, 2004). Despite the evidence suggesting healthy eating and exercise habits to reduce chronic disease, college students typically do not meet their own stated goals for exercise and nutrition, or goals set forth by national guidelines (Walace, et al., 2000). Therefore, a college campus is a challenging yet necessary setting for people to overcome barriers and obstacles in their lives that may …

The Analysis Of Two Different Types Of Tapers On Exercise Performance, Christina Rial, David L. Nichols Ph.D., Facsm

International Journal of Exercise Science: Conference Proceedings

The purpose of this study was to compare the differences in a step taper and an exponential decay taper across time. The subjects were randomly divided into two groups, the step (n = 9) or exponential decay (n = 11) group. The participant’s baseline tested, trained for 4 weeks, pre tested, tapered for one week, and then post tested. The exponential group (15.56 ± 1.33; 10.64 ± 1.21) had a significantly lower RPE compared to the step group (16.20 ± 2.68; 11.13 ± 0.64) in stage 4 of the pretest and in stage 2 of the posttest (p ≤ .05). …

Maintenance Of Mitochondrial Genomic Integrity In The Absence Of Manganese Superoxide Dismutase In Mouse Liver Hepatocytes., Anthony R. Cyr, Kyle E. Brown, Michael L. Mccormick, Mitchell C. Coleman, Adam J. Case, George S. Watts, Bernard W. Futscher, Douglas R. Spitz, Frederick E. Domann

Journal Articles: Cellular & Integrative Physiology

Manganese superoxide dismutase, encoded by the Sod2 gene, is a ubiquitously expressed mitochondrial antioxidant enzyme that is essential for mammalian life. Mice born with constitutive genetic knockout of Sod2 do not survive the neonatal stage, which renders the longitudinal study of the biochemical and metabolic effects of Sod2 loss difficult. However, multiple studies have demonstrated that tissue-specific knockout of Sod2 in murine liver yields no observable gross pathology or injury to the mouse. We hypothesized that Sod2 loss may have sub-pathologic effects on liver biology, including the acquisition of reactive oxygen species-mediated mitochondrial DNA mutations. To evaluate this, we established …