Exercise Science Commons^™

Triathlon Training For Women Breast Cancer Survivors: Feasibility And Initial Efficacy, Alex V. Ng, Alyson Cybulski, Ashley A. Engel, Paula E. Papanek, Megn A. Sheffer, Leslie J. Waltke, Judy A. Tjoe

Exercise Science Faculty Research and Publications

Exercise can improve quality of life (QOL) in breast cancer survivors. In contrast to many group or home-based exercise programs, little is known about the effectiveness of goal-oriented recreational activities.

Purpose

The purpose of this study was to evaluate a clinically overseen team triathlon training program on improving physiological and psychosocial health-related measures in female breast cancer survivors.

Methods

Twenty-three participants (age = 48 (8), BMI = 25 (1), mean (SE)) were recruited from a 14-week sprint triathlon (800-m swim, 20-km bike, 5-km run) team training program for women breast cancer survivors (4 (3) years post-surgery, chemo-, or radiation-therapy). Training …

Sex Differences In Neuromuscular Fatigability Of The Knee Extensors Post-Stroke, Meghan Kirking, Reivian B. Barillas, Philip A. Nelson, Sandra K. Hunter, Allison Hyngstrom

Exercise Science Faculty Research and Publications

Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women) with chronic stroke (≥6 months) and 23 (12 men, 11 women) nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest) at 30% of maximal voluntary contraction (MVC) torque until failure to maintain the target …

Rates Of Performance Loss And Neuromuscular Activity In Men And Women During Cycling: Evidence For A Common Metabolic Basis Of Muscle Fatigue, Christopher W. Sundberg, Sandra K. Hunter, Matthew W. Bundle

Exercise Science Faculty Research and Publications

The durations that muscular force and power outputs can be sustained until failure fall predictably on an exponential decline between an individual’s 3-s burst maximum to the maximum performance they can sustain aerobically. The exponential time constants describing these rates of performance loss are similar across individuals, suggesting that a common metabolically based mechanism governs muscle fatigue; however, these conclusions come from studies mainly on men. To test whether the same physiological understanding can be applied to women, we compared the performance-duration relationships and neuromuscular activity between seven men [23.3 ± 1.9 (SD) yr] and seven women (21.7 ± 1.8 …

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 …

Short-Interval Cortical Inhibition And Intracortical Facilitation During Submaximal Voluntary Contractions Changes With Fatigue, Sandra K. Hunter, Chris J. Mcneil, Jane E. Butler, Simon C. Gandevia, Janet L. Taylor

Exercise Science Faculty Research and Publications

This study determined whether short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) change during a sustained submaximal isometric contraction. On 2 days, 12 participants (6 men, 6 women) performed brief (7-s) elbow flexor contractions before and after a 10-min fatiguing contraction; all contractions were performed at the level of integrated electromyographic activity (EMG) which produced 25 % maximal unfatigued torque. During the brief 7-s and 10-min submaximal contractions, single (test) and paired (conditioning–test) transcranial magnetic stimuli were applied over the motor cortex (5 s apart) to elicit motor-evoked potentials (MEPs) in biceps brachii. SICI and ICF were elicited on separate …

Fast Men Slow More Than Fast Women In A 10 Kilometer Road Race, Robert O. Deaner, Vittorio Addana, Rickey E. Carter, Michael J. Joyner, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Background. Previous studies have demonstrated that men are more likely than women to slow in the marathon (footrace). This study investigated whether the sex difference in pacing occurs for a shorter race distance.

Materials & Methods.Data were acquired from the Bolder Boulder 10 km road race for the years 2008–2013, which encompassed 191,693 performances. There were two pacing measures, percentage change in pace of the first 3 miles relative to the final 3.2 miles and percentage change in pace of the first mile relative to the final 5.2 miles. Pacing was analyzed as a continuous variable and as two …

Toward Translating Near-Infrared Spectroscopy Oxygen Saturation Data For The Non-Invasive Prediction Of Spatial And Temporal Hemodynamics During Exercise, Laura M. Ellwein, Margaret M. Samyn, Michael E. Danduran, Sheila M. Schindler-Ivens, Stacy Liebham, John F. Ladisa Jr.

Exercise Science Faculty Research and Publications

Image-based computational fluid dynamics (CFD) studies conducted at rest have shown that atherosclerotic plaque in the thoracic aorta (TA) correlates with adverse wall shear stress (WSS), but there is a paucity of such data under elevated flow conditions. We developed a pedaling exercise protocol to obtain phase contrast magnetic resonance imaging (PC-MRI) blood flow measurements in the TA and brachiocephalic arteries during three-tiered supine pedaling at 130, 150, and 170 % of resting heart rate (HR), and relate these measurements to non-invasive tissue oxygen saturation (StO₂) acquired by near-infrared spectroscopy (NIRS) while conducting the same protocol. Local quantification …

Molecular Underpinnings Of Diabetic Polyneuropathy, Jonathon Senefeld, Sandra K. Hunter

Exercise Science Faculty Research and Publications

No abstract provided.

Effect Of Fontan Fenestration On Regional Venous Oxygen Saturation During Exercise: Further Insights Into Fontan Fenestration Closure, Rohit S. Loomba, Michael E. Danduran, Jennifer E. Dixon, Rohit P. Rao

Exercise Science Faculty Research and Publications

Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients …

The Effect Of Concurrent Activation Potentiation During Fast Stretch Shortening Cycle Activity, Erich Petushek, Luke Garceau, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the effect of remote voluntary contractions (RVC) on depth jump performance. Subjects performed the depth jump in a RVC condition and a condition without RVC (NO-RVC). Ground reaction force (GRF), impulse (I), and reactive strength index (RSI) were assessed with a force platform. Data were analyzed using a two way ANOVA. Analysis of GRF showed no significant main effects for RVC condition (p = 0.46) and no interaction for RVC condition and gender (p = 0.11). Analysis of I showed no significant main effects for RVC condition (p = 0.99) and no interaction for RVC condition and …

The Acute Time Course Of Concurrent Activation Potentiation, Luke Garceau, Erich Petushek, Mckenzie Fauth, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the acute time course of the ergogenic effect of concurrent activation potentiation (CAP). Forty-two men and women, including CAP non-responders and responders, performed a 5 second isometric knee extension on a dynamometer with the use of remote voluntary contractions (RVC). Mean torque was assessed in seven 500 millisecond (ms) time periods. A two-way repeated measures ANOVA revealed significant main effects for time period (p ≤ 0.001), but no significant interaction between time period and CAP non-responders and responders (p > 0.05). The ergogenic effects of CAP are accrued during the first 1000ms. Concurrent activation potentiation responders produce greater …

Dynamic Stabilization During The Landing Phase Of Plyometric Exercises, Erich Petushek, Luke Garceau, Tyler Vanderzanden, Brad Wurm, Christina Feldmann, William Ebben

Exercise Science Faculty Research and Publications

This study examined the differences in and the reliability of time to stabilization (TTS) of several plyometric exercises. Twenty six men performed a variety of plyometric exercises representing a continuum of intensities of landing instability, including line hops, cone hops, squat jumps, tuck jumps, countermovement jumps, dumbbell countermovement jumps, and single leg countermovement jumps on a force platform. A repeated measures ANOVA with Bonferroni post hoc corrections was used to evaluate the differences in TTS between plyometric exercises. Practitioners who use plyometrics to train dynamic stability and balance should create programs that progress the intensity of the exercises based on …

The Effect Of Concurrent Activation Potentiation On The Knee Extensor And Flexor Performance Of Men And Women, Luke Garceau, Erich Petushek, Mckenzie Fauth, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the effect of remote voluntary contractions (RVC) during isometric and isokinetic knee flexion and extension tests and evaluated gender differences therein. Subject peak torque, rate of torque development, and power were assessed with a dynamometer in RVC and no RVC’s conditions. A two way mixed ANOVA with repeated measures for condition was used to evaluate the interaction between conditions and gender, and to assess the main effects. Main effects were evaluated with a paired samples t-test. Results revealed a significant interaction between all but one test condition and gender as well as significant main effects for all …

Kinetic Quantification Of Plyometric Take Off, Flight, And Landing Characteristics, William Ebben, Tyler Vanderzanden, Brad Wurm, Luke Garceau, Christina Feldmann, Erich Petushek

Exercise Science Faculty Research and Publications

This study assessed the kinetic characteristics of a variety of plyometric exercises and assessed gender differences therein. Twenty-six men and 23 women performed a variety of plyometric exercises including line hops, 15.24 cm cone hops, squat jumps, tuck jumps, countermovement jumps, loaded countermovement jumps equal to 30% of 1 RM squat, depth jumps normalized to the subjects jump height, and single leg jumps. All plyometric exercises were performed on a force platform. Outcome variables associated with the takeoff, airborne, and landing phase of each plyometric were assessed including the peak ground reaction force during takeoff, time to takeoff, jump height, …

Antagonist Conditioning Contractions Impair Agonist Functioning, Luke Garceau, Aaron Gray, Mckenzie Fauth, Phillip Hanson, Brittni Hsu, Tejin Yoon, Chris Szalkowski, Brittney Lutsch, William Ebben

Exercise Science Faculty Research and Publications

This study assessed the effect of antagonist conditioning contractions (ACC) on the subsequent force and electromyography of an agonist. Twelve subjects performed isokinetic elbow flexion on a dynamometer in 4 test conditions including a baseline condition without, and 1, 3 and 6 seconds after, isometric triceps extension. Average peak torque (T), peak torque/body weight (T:BW), average power (P), and rate of torque development (RTD) were assessed. Electromyographic data were obtained from elbow extensors and flexors. A repeated measures ANOVA with post hoc analysis demonstrated that T, T:BW, P, and RTD were higher in the baseline, compared to the post ACC …

Quantifying The Onset Of The Concentric Phase Of The Force–Time Record During Jumping, S.K. Leissring, William Ebben, Luke Garceau, Erich Petushek, R.L. Jensen

Exercise Science Faculty Research and Publications

Thirteen college students performed a drop jump from height equal to their peak vertical jump, single leg jumps from the left and right legs, and a counter movement jump. Vertical ground reaction force (GRF) obtained via an AMTI force plate and video analysis of markers placed on the hip, knee, lateral malleolus, and fifth metatarsal were used to estimate reaction forces on the knee joint. One-way Repeated Measures ANOVA indicated no differences for knee joint reaction forces relative to body weight or peak GRF for any of the jumps (p > 0.05). Average measures Intraclass Correlation Coefficients ranged from r = …