Kinesiology Commons^™

Gait Complexity Is Acutely Restored In Older Adults When Walking To A Fractal-Like Visual Stimulus, Joao R. Vaz, Brian Knarr, Nicholas Stergiou

Journal Articles

Typically, gait rehabilitation uses an invariant stimulus paradigm to improve gait related deficiencies. However, this approach may not be optimal as it does not incorporate gait complexity, or in more precise words, the variable fractal-like nature found in the gait fluctuations commonly observed in healthy populations. Aging which also affects gait complexity, resulting in a loss of adaptability to the surrounding environment, could benefit from gait rehabilitation that incorporates a variable fractal-like stimulus paradigm. Therefore, the present study aimed to investigate the effect of a variable fractal-like visual stimulus on the stride-to-stride fluctuations of older adults during overground walking. Additionally, …

Aging, Gait Variability, And Adaptability, Collin Douglas Bowersock

Health Services Research Dissertations

The purpose of this work was to study the relationships between age, measures of gait variability, and locomotor adaptability. Measures of gait variability are used to identify maladapted locomotor behavior, motor disease, and risk of falls. The first aim was to determine the relationships between age and measures of gait variability. Thirty-four participants (23-71 years old) walked on a treadmill for 6 minutes at their preferred speed. Variability of stride times and lengths was computed via linear measures (standard deviation and coefficient of variation) and nonlinear measures (sample entropy and detrended fluctuation analysis). Movement trajectory variability of the dominant knee …

Assessing The Temporal Organization Of Walking Variability: A Systematic Review And Consensus Guidelines On Detrended Fluctuation Analysis, Deepak K. Ravi, Vivien Marmelat, William R. Taylor, Karl M. Newell, Nicholas Stergiou, Navrag B. Singh

Journal Articles

Human physiological signals are inherently rhythmic and have a hallmark feature in that even distant intrasignal measurements are related to each other. This relationship is termed long-range correlation and has been recognized as an indicator of the optimal state of the observed physiological systems, among which the locomotor system. Loss of long-range correlations has been found as a result of aging as well as disease, which can be evaluated with detrended fluctuation analysis (DFA). Recently, DFA and the scaling exponent α have been employed for understanding the degeneration of temporal regulation of human walking biorhythms in, for example, Parkinson disease …

Early And Late Rapid Torque Characteristics And Select Physiological Correlates In Middle-Aged And Older Males, Alex A. Olmos, Matthew T. Stratton, Phuong L. Ha, Benjamin E. Dalton, Trisha Vandusseldorp, Gerald Mangine, Yuri Feito, Micah J. Poisal, Joshua A. Jones, Tyler M. Smith, Garrett Hester

Faculty Articles

Purpose

The purpose of this study was to compare early and late rapid torque parameters of the plantar flexors (PFs) in middle-aged (MM) and older (OM) males, and determine the effect of normalization to peak torque (PT) and muscle cross-sectional area (CSA).

Methods

Twenty-nine healthy, MM (n = 14; 45 ± 2 yrs) and OM (n = 15; 65 ± 3 yrs) performed rapid, maximal isometric contractions of the PFs. PT, as well as rate of torque development and impulse during the early (0–50 ms; RTD_0-50, IMP_0-50) and late (100–200 ms; RTD_100-200, IMP_{100-200 …}

Insights On Ten Weeks Of Classical Ballet Training And Postural Stability In Older Adults, Hannah Weighart, Sarah Dipasquale

International Journal of Exercise Science

International Journal of Exercise Science 13(1): 101-112, 2020. Older adults show an increased risk of falling as they age, but dance interventions of various genres have been shown to improve postural stability in this population. The purpose of this study was to investigate the effects of a ten-week beginning ballet intervention on postural stability for older adults. Eleven participants enrolled in the Dance Group (DG; 73.3 ± 10.6 years) while six enrolled in the Control Group (CG; 69.5 ± 11.9 years) via convenience sample. Following the intervention, no significant differences were seen within the DG from pre- to post-testing or …

Biomechanics In The 4haie Study: Air Pollution And Musculoskeletal Health - An Update, Daniel Jandacka, Jaroslav Uchityil, David Zahradník, Roman Farana, Dominik Villimek, Jiri Skypala, Jan Urbaczka, Jan Plesek, Adam Motyka, Denisa Blaschova, Gabriela Beinhauerova, Marketa Rygelová, Pavel Brtva, Zuzana Golembiovska, Klara Balazova, Jan Malus, Veronika Horka, Julia F. Silvernail, Gareth Irwin, Miika T. Nieminen, Victor Casula, Vlado Juras, Milos Golian, Steriani Elavsky, Lenka Knapova, Radim Sram, Joseph Hamill

Kinesiology and Nutrition Sciences Faculty Research

The overall purpose of the 4HAIE study was to assess the influence of the interaction between air pollution and biomechanical, physiological and psychosocial factors on the incidence of injuries, health and well-being. A total of 1,500 active runners and inactive controls aged 18-65 will be recruited. Herein, we describe the biomechanical study design with data examples to investigate musculoskeletal and neuro-mechanics health in different air quality regions.

Serum Myostatin And Igf-1 As Biomarkers Of Sarcopenia: A Proof-Of-Concept Design, Ashley Binns

Graduate Theses and Dissertations

The population comprising older adults is growing exponentially, as are healthcare related costs. Nearly $20 billion is annually expensed by older adults for health-related issues affiliated with age-related decline in skeletal muscle mass. Yet, diagnostic criteria are not readily utilized in clinical practice. PURPOSE: Therefore, the purpose of this study was to provide evidence for use of blood biomarkers (myostatin, IGF-1) to predict appendicular skeletal muscle mass (ASM) among middle-aged and older adults. METHODS: A cross-sectional study was conducted among 106 individuals (n = 68 females; n = 38 males) aged ≥ 40 years of age (60.1 ± 11.1 y) …

The Association Of Coordination With Physical Activity Levels Of Older Adults, Eric G. James, Murat Karabulut, Phillip Conatser, Suzanne G. Leveille, Soham Al Snih, Kyriakos S. Markides, Jonathan F. Bean

Health & Human Performance Faculty Publications

Aim: To examine the association between coordination ability and self-reported physical activity among community dwelling older adults.

Methods: We conducted a cross-sectional study of 77 adults (81.51 ± 5.46 years) using motion capture and a gait walkway to assess rhythmic interlimb ankle, shoulder, and gait coordination. Physical activity was assessed using the Physical Activity Scale for the Elderly (PASE). We conducted multivariable linear regression modeling using backward elimination with age, gender, body mass index, Mini-Mental State Exam score, number of chronic conditions, falls, Short Physical Performance Battery (SPPB) score, and interlimb ankle, shoulder, and gait coordination as predictors, and PASE …

Metformin Blunts Muscle Hypertrophy In Response To Progressive Resistance Exercise Training In Older Adults: A Randomized, Double‐Blind, Placebo‐Controlled, Multicenter Trial: The Masters Trial, R. Grace Walton, Cory M. Dungan, Douglas E. Long, S. Craig Tuggle, Kate Kosmac, Bailey D. Peck, Heather M. Bush, Alejandro G. Villasante Tezanos, Gerald Mcgwin, Samuel T. Windham, Fernando Ovalle, Marcas M. Bamman, Philip A. Kern, Charlotte A. Peterson

Center for Muscle Biology Faculty Publications

Progressive resistance exercise training (PRT) is the most effective known intervention for combating aging skeletal muscle atrophy. However, the hypertrophic response to PRT is variable, and this may be due to muscle inflammation susceptibility. Metformin reduces inflammation, so we hypothesized that metformin would augment the muscle response to PRT in healthy women and men aged 65 and older. In a randomized, double-blind trial, participants received 1,700 mg/day metformin (N = 46) or placebo (N = 48) throughout the study, and all subjects performed 14 weeks of supervised PRT. Although responses to PRT varied, placebo gained more lean body …

Does Acute Preprandial Exercise Modify Postprandial Inflammation After A High Fat Meal In Young And Older Adults?, William Wisseman

Masters Theses, 2010-2019

A single high-fat meal (HFM) can increase systemic inflammation (postprandial inflammation; PPI) and may be attenuated by recent exercise. However, the effect of preprandial exercise on PPI in older adults (OA) is not clear. Purpose: To determine if preprandial exercise attenuates PPI in YA and OA. Methods: 12 YA (23.3±3.9 years n= 5 M/7 F) and 12 OA (67.7±6 years, n= 8 M/4 F) completed two HFM challenges in a randomized order. During HFM alone, participants abstained from exercise 48 hours prior to the HFM session (except for the exercise session) and adhered to a 12 hour overnight …

Arterial Stiffness During Whole-Body Passive Heat Stress In Healthy Older Adults, Zachary J. Schlader, Yoshiyuki Okada, Stuart A. Best, Qi Fu, Craig G. Crandall

Kinesiology and Health Promotion Faculty Publications

We tested the hypothesis that whole‐body passive heat stress reduces arterial stiffness in older adults. At preheat stress (baseline) and when core temperature was elevated by 0.6 ± 0.2°C (mild) and 1.2 ± 0.3°C (moderate), arterial stiffness was measured in eight healthy younger (26 ± 5 years) and eight healthy older (70 ± 4 years) adults in the supine position. Arterial stiffness was estimated from carotid‐to‐femoral pulse wave velocity (cfPWV, applanation tonometry). cfPWV was higher at baseline in older adults (8.8 ± 2.3 m/sec vs. 5.6 ± 0.9 m/sec, P < 0.01) and this difference was maintained throughout passive heat stress (P < 0.01). cfPWV did not change (P ≥ 0.49) with passive heat stress in either …

Similar Effects Of 24 Weeks Of Resistance Training Performed With Different Frequencies On Muscle Strength, Muscle Mass, And Muscle Quality In Older Women, Fábio Luiz Cheche Pina, João Pedro Nunes, Matheus Amarante Nascimento, Alex Silva Ribeiro, Jerry L. Mayhew, Edilson Serpeloni Cyrino

International Journal of Exercise Science

International Journal of Exercise Science 12(6): 623-635, 2019. The purpose of this study was to analyze the effects of 24 weeks of resistance training (RT) performed 2 vs. 3 times per week on muscle strength, muscle mass, and muscle quality in older women. Thirty-nine older women (≥ 60 years old) were randomly assigned to two groups according to RT frequency (G2x = two sessions per week, n=19; and G3x = three sessions per week, n=20) and were submitted to 24 weeks of whole-body RT, divided into two stages of 12 weeks. In the first stage, participants performed 1 set of …

Autophagy And Aging: Maintaining The Proteome Through Exercise And Caloric Restriction, Kurt A. Escobar, Nathan H. Cole, Christine M. Mermier, Trisha A. Vandusseldrop

Faculty Articles

Accumulation of dysfunctional and damaged cellular proteins and organelles occursduring aging, resulting in a disruption of cellular homeostasis and progressive degen-eration and increases the risk of cell death. Moderating the accrual of these defunctcomponents is likely a key in the promotion of longevity. While exercise is knownto promote healthy aging and mitigate age‐related pathologies, the molecular under-pinnings of this phenomenon remain largely unclear. However, recent evidencessuggest that exercise modulates the proteome. Similarly, caloric restriction (CR), aknown promoter of lifespan, is understood to augment intracellular protein quality.Autophagy is an evolutionary conserved recycling pathway responsible for thedegradation, then turnover of cellular proteins …

Body Composition, Muscular Performance, And Free Testosterone Following 12-Weeks Of Protein Supplementation And Resistance Training In Men Aged 35-55, Matthew Steven Stone

Graduate Theses and Dissertations

PURPOSE: The purpose of this study was to investigate the effects of 12 weeks of protein supplementation and Autoregulatory Progressive Resistance Exercise (APRE) training on measures of body composition, muscular performance, and free testosterone in middle-aged men. METHODS: Untrained males (n = 35; 43.3 ± 6.6 years) participated in this study. Lean mass (LM) and fat mass (FM) were measured via Dual Energy X-ray Absorptiometry (DEXA), while strength was measured utilizing one repetition maximum (1RM), endurance measured using maximum repetitions completed (REPS) at 75% 1RM for the bench and leg press, and free testosterone was measured using changes in serum …

Relative Handgrip Strength As A Simple Tool To Evaluate Impaired Heart Rate Recovery And A Low Chronotropic Index In Obese Older Women, Cristiane Rocha Da Silva, Dahan Da Cunha Nascimento, Ivo Sousa Neto, Ramires Tibana, Samuel Oliveira, Renato Valduga, Nayara Santos, Bruno Saraiva, Jonato Prestes, Jeffrey Willardson, Guilherme Borges Pereira

International Journal of Exercise Science

International Journal of Exercise Science 11(2): 844-855, 2018. The aim of the present study was to compare differences in heart rate response following a treadmill exercise test in elderly obese women categorized into groups based on relative handgrip strength. Eighty-eight obese elderly women who were between the ages of 60 and 87 participated in the study and were categorized and enrolled to one of two groups based on lower (< 1.51 m²) or higher (≥ 1.51 m²) relative handgrip strength, respectively. The heart rate recovery in the first and second minutes following the treadmill exercise test and the chronotropic index were compared between groups. The higher relative handgrip strength group presented a significantly higher peak heart rate during exercise and a quicker heart rate recovery following exercise versus the lower relative handgrip strength group (pp=0.059) toward a significantly greater chronotropic index in the higher versus the lower relative handgrip strength group. In conclusion, elderly women with greater relative handgrip strength also demonstrated a …

Skeletal Muscle Oxidative Capacity In The Elderly, Susie Chung

Kinesiology Theses - Archive

Age is the greatest risk factor for chronic disease and is associated with a marked decline in functional capacity and quality of life, with loss of skeletal muscle function regarded as a key contributing factor. While the exact mechanism(s) for the loss of skeletal muscle function remains incompletely understood, age-related mitochondrial dysfunction is thought to play a major role. To explore this question further, we studied 15 independently-living seniors (age: 72 ± 5 yrs; m/f: 4/11; BMI: 27.6 ± 5.9) and 17 young volunteers (age: 25 ± 4 years; m/f: 8/9; BMI: 24.0 ± 3.3). Skeletal muscle oxidative function was …

The Effects Of Bingocize® On Cognitive Aging: A Health Promotion Intervention, Rilee Pauline Mathews

Masters Theses & Specialist Projects

Previous research has suggested that physical exercise can play a role in not only improving functional performance, but also cognitive function. In this study, adults age 60 and older participated in a health promotion intervention that included two groups: (a) a Bingocize® group, who exercised and learned about relevant health information while playing bingo, and (b) a control group who only learned about relevant health information while playing bingo. The intervention was completed over the course of 10- weeks at community senior centers. Cognitive function, functional fitness, and health knowledge were assessed before and after the intervention to test for …

Serum Tumor Necrosis Factor-Alpha Associates With Myocardial Oxygen Demand And Exercise Tolerance In Postmenopausal Women, Stephen J. Carter, David R. Bryan, William H. Neumeier, Stephen P. Glasser, Gary R. Hunter

International Journal of Exercise Science

International Journal of Exercise Science 11(2): 42-54, 2018. The functional implications of serum tumor necrosis factor-alpha (TNF-a), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-a on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-a on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO_2max). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index …

Serum Tumor Necrosis Factor-Alpha Associates With Myocardial Oxygen Demand And Exercise Tolerance In Postmenopausal Women, Stephen J. Carter, David R. Bryan, William H. Neumeier, Stephen P. Glasser, Gary R. Hunter

Internal Medicine Faculty Publications

The functional implications of serum tumor necrosis factor-alpha (TNF-α), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-α on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-α on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO_2max). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index of myocardial oxygen demand, was measured at rest …

Posture And Gaze Tracking Of A Vertically Moving Target Reveals Age-Related Constraints In Visuo-Motor Coupling, Haralampos Sotirakis, Anastasia Kyvelidou, Nicholas Stergiou, Vassilia Hatzitaki

Journal Articles

Previously we have demonstrated that the effect of aging on posture and gaze active tracking of a visual target moving in the horizontal direction is dependent on target’s complexity. In this study, we asked whether a similar phenomenon is present when tracking a visual target moving with varying complexity in the vertical direction. Ten young (22.98 ± 2.9 years) and 10 older adults (72.45 ± 4.72 years) tracked for 120 s, a visual target moving vertically by shifting their bodyweight in the anterior-posterior direction. Three target motions were tested: a simple periodic (sine wave), a more complex (Lorenz attractor) and …

Impact Of Age On Cerebrovascular Dilation Versus Reactivity To Hypercapnia., Nicole S Coverdale, Mark B Badrov, J Kevin Shoemaker

Kinesiology Publications

This study quantified the effect of age on cerebrovascular reactivity and cerebrovascular conductance while accounting for differences in grey matter volume in younger (YA: n = 12; 24 ± 4 years, six females) and older adults (OA: n = 10; 66 ± 7 years; five females). Cerebral blood flow velocity (CBFV; transcranial Doppler) in the middle cerebral artery (MCA), MCA cross-sectional area (CSA), intracranial volumes (magnetic resonance imaging), and mean arterial pressure (MAP; Finometer), were measured under normocapnic and hypercapnic (6% carbon dioxide) conditions. Cerebral blood flow (CBF) was quantified from CBFV and MCA CSA and normalized to grey matter …

Age Differences In Dynamic Fatigability And Variability Of Arm And Leg Muscles: Associations With Physical Function, Jonathon Senefeld, Tejin Yoon, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Introduction

It is not known whether the age-related increase in fatigability of fast dynamic contractions in lower limb muscles also occurs in upper limb muscles. We compared age-related fatigability and variability of maximal-effort repeated dynamic contractions in the knee extensor and elbow flexor muscles; and determined associations between fatigability, variability of velocity between contractions and functional performance.

Methods

35 young (16 males; 21.0 ± 2.6 years) and 32 old (18 males; 71.3 ± 6.2 years) adults performed a dynamic fatiguing task involving 90 maximal-effort, fast, concentric, isotonic contractions (1 contraction/3 s) with a load equivalent to 20% maximal voluntary isometric …

The Aging Neuromuscular System And Motor Performance, Sandra K. Hunter, Hugo M. Pereira, Kevin Keenan

Exercise Science Faculty Research and Publications

Age-related changes in the basic functional unit of the neuromuscular system, the motor unit, and its neural inputs have a profound effect on motor function, especially among the expanding number of old (older than ∼60 yr) and very old (older than ∼80 yr) adults. This review presents evidence that age-related changes in motor unit morphology and properties lead to impaired motor performance that includes 1) reduced maximal strength and power, slower contractile velocity, and increased fatigability; and 2) increased variability during and between motor tasks, including decreased force steadiness and increased variability of contraction velocity and torque over …

Effects Of Aging And Coronary Artery Disease On Sympathetic Neural Recruitment Strategies During End-Inspiratory And End-Expiratory Apnea, Mark B. Badrov, Sophie Lalande, T Dylan Olver, Neville Suskin, J Kevin Shoemaker

Kinesiology Publications

In response to acute physiological stress, the sympathetic nervous system modifies neural outflow through increased firing frequency of lower-threshold axons, recruitment of latent subpopulations of higher-threshold axons, and/or acute modifications of synaptic delays. Aging and coronary artery disease (CAD) often modify efferent muscle sympathetic nerve activity (MSNA). Therefore, we investigated whether CAD (n = 14; 61 ± 10 yr) and/or healthy aging without CAD (OH; n = 14; 59 ± 9 yr) modified these recruitment strategies that normally are observed in young healthy (YH; n = 14; 25 ± 3 yr) individuals. MSNA (microneurography) was measured at baseline and during …

Effects Of Aging On The Relationship Between Cognitive Demand And Step Variability During Dual-Task Walking, Leslie M. Decker, Fabien Cignetti, Nathaniel Hunt, Jane F. Potter, Nicholas Stergiou, Stephanie A. Studenski

Journal Articles

A U-shaped relationship between cognitive demand and gait control may exist in dual-task situations, reflecting opposing effects of external focus of attention and attentional resource competition. The purpose of the study was twofold: to examine whether gait control, as evaluated from step-to-step variability, is related to cognitive task difficulty in a U-shaped manner and to determine whether age modifies this relationship. Young and older adults walked on a treadmill without attentional requirement and while performing a dichotic listening task under three attention conditions: non-forced (NF), forced-right (FR), and forced-left (FL). The conditions increased in their attentional demand and requirement for …

Power Training And Functional Performance In Middle Aged Women: A Pilot Study, Mitchel A. Magrini, J. Jay Dawes, Craig Elder, Mary Ann Kluge

International Journal of Exercise Science

International Journal of Exercise Science 9(3): 327-335, 2016. Muscular power is a key component of functional performance (FP) and fall risk reduction. The present study investigated the effect that power training with medicine balls had on body composition and FP in middle-age females. 10 women were divided into a control group (n=4, age=59.8+3.6) and an intervention group (n=6, age=59.5+3.6) in this 6-week study. The intervention group completed a medicine ball training program two times a week. Body composition and FP tests were administered prepost. Data was analyzed using a series of Wilcoxon Signed Ranks test and Cohen’s d test for …

Only Women Report Increase In Pain Threshold Following Fatiguing Contractions Of The Upper Extremity, Kathy J. Lemley, Jonathon Senefeld, Sandra K. Hunter, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

Purpose

The perception of pain in response to a noxious stimulus can be markedly reduced following an acute bout of exercise [exercise-induced hypoalgesia (EIH)]. Sex differences in EIH frequently occur after exercise but may be confounded by the sex differences in muscle fatigue. The purpose was to determine if sex differences in pain relief occur after an exercise protocol when muscle fatigue is similar for both young and older men and women.

Methods

Pain perception of 33 men (15 young) and 31 women (19 young) was measured using a pressure pain stimulus on the left index finger before and after …

Hypertrophy-Promoting Effects Of Leucine Supplementation And Moderate Intensity Aerobic Exercise In Pre-Senescent Mice, Zhi Xia, Jason Cholewa, Yan Zhao, Yue Qin Yang, Hua Yu Shang, Lucas Guimarães-Ferreira, Marshall Alan Naimo, Quan Sheng Su, Nelo Eidy Zanchi

Kinesiology

Several studies have indicated a positive influence of leucine supplementation and aerobic training on the aging skeletal muscle signaling pathways that control muscle protein balance and muscle remodeling. However, the effect of a combined intervention requires further clarification. Thirteen month old CD-1® mice were subjected to moderate aerobic exercise (45 min swimming per day with 3% body weight workload) and fed a chow diet with 5% leucine or 3.4% alanine for 8 weeks. Serum and plasma were prepared for glucose, urea nitrogen, insulin and amino acid profile analysis. The white gastrocnemius muscles were used for determination of muscle size and …

Aging Affects Postural Tracking Of Complex Visual Motion Cues, Haralampos Sotirakis, Anastasia Kyvelidou, L. Mademli, Nicholas Stergiou, Vassilia Hatzitaki

Journal Articles

Postural tracking of visual motion cues improves perception–action coupling in aging, yet the nature of the visual cues to be tracked is critical for the efficacy of such a paradigm. We investigated how well healthy older (72.45 ± 4.72 years) and young (22.98 ± 2.9 years) adults can follow with their gaze and posture horizontally moving visual target cues of different degree of complexity. Participants tracked continuously for 120 s the motion of a visual target (dot) that oscillated in three different patterns: a simple periodic (simulated by a sine), a more complex (simulated by the Lorenz attractor that is …

Impact Of Age On The Vasodilatory Function Of Human Skeletal Muscle Feed Arteries, Song-Young Park, S. J. Ives, J. R. Gifford, R. H. I. Andtbacka, John R. Hyngstrom, Van Reese, Gwenael Layec, Leena P. Bharath, J. David Symons, Russell S. Richardson

Health and Kinesiology Faculty Publications

Although advancing age is often associated with attenuated skeletal muscle blood flow and skeletal muscle feed arteries (SMFAs) have been recognized to play a regulatory role in the vasculature, little is known about the impact of age on the vasodilatory capacity of human SMFAs. Therefore, endothelium-dependent and -independent vasodilation were assessed in SMFAs (diameter: 544 ± 63 μm) obtained from 24 (equally represented) young (33 ± 2 yr) and old (71 ± 2 yr) subjects in response to three stimuli: 1) flow-induced shear stress, 2) ACh, and 3) sodium nitropusside (SNP). Both assessments of endothelium-dependent vasodilation, flow …