Sports Medicine Commons^™

Returners Exhibit Greater Jumping Performance Improvements During A Peaking Phase Compared With New Players On A Volleyball Team, Caleb D. Bazyler, Satoshi Mizuguchi, Ashley A. Kavanaugh, John J. Mcmahon, Paul Comfort, Michael H. Stone

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Purpose: To determine if jumping-performance changes during a peaking phase differed among returners and new players on a female collegiate volleyball team and to determine which variables best explained the variation in performance changes.

Methods: Fourteen volleyball players were divided into 2 groups—returners (n = 7) and new players (n = 7)—who completed a 5-wk peaking phase prior to conference championships. Players were tested at baseline before the preseason on measures of the vastus lateralis cross-sectional area using ultrasonography, estimated back-squat 1-repetition maximum, countermovement jump height (JH), and relative peak power on a force platform. Jumping performance, rating of perceived …

A Cross-Training Program Does Not Alter Self-Reported Physical Activity Levels In Elementary School Children, Melody L. White, Matthew S. Renfrow, Richards S. Farley, Dana K. Fuller, Brandi M. Eveland-Sayers, Jennifer L. Caputo

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The purpose of the study was to examine the effects of a school-based cross-training program on body mass index (BMI), attitudes toward physical activity (ATPA), and physical activity (PA) levels of children in the 4^th and 5^th grades. Children (N = 118) were divided into control (n = 60) and experimental (n = 58) groups based on class availability. While the control group continued academic classes as usual, the experimental group participated in cross-training involving resistance training (RT), calisthenics, and stretching twice a week for 10 weeks. Pre- and post-intervention measures included height, mass, ATPA, and PA. BMI …

Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone

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Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force …

The Demands Of A Women's College Soccer Season, Jeremy A. Gentles, Christine L. Coniglio, Matthew M. Besemer, Joshua M. Morgan, Michael T. Mahnken

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No abstract provided.

Current Research And Statistical Practices In Sport Science And A Need For Change, Jake R. Bernards, Kimitake Sato, G. Gregory Haff, Caleb D. Bazyler

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Current research ideologies in sport science allow for the possibility of investigators producing statistically significant results to help fit the outcome into a predetermined theory. Additionally, under the current Neyman-Pearson statistical structure, some argue that null hypothesis significant testing (NHST) under the frequentist approach is flawed, regardless. For example, a p-value is unable to measure the probability that the studied hypothesis is true, unable to measure the size of an effect or the importance of a result, and unable to provide a good measure of evidence regarding a model or hypothesis. Many of these downfalls are key questions researchers strive …

Maximum Strength, Rate Of Force Development, Jump Height, And Peak Power Alterations In Weightlifters Across Five Months Of Training, W. Guy Hornsby, Jeremy A. Gentles, Christopher J. Macdonald, Satoshi Mizuguchi, Michael W. Ramsey, Michael H. Stone

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The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate …

Increases In Variation Of Barbell Kinematics Are Observed With Increasing Intensity In A Graded Back Squat Test, Kevin M. Carroll, Kimitake Sato, Caleb D. Bazyler, N. Travis Triplett, Michael H. Stone

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The purpose of the current study was two-fold: (1) To examine the variation in velocity and power with increasing intensity in the back squat among subjects; and (2) To explore individual subject characteristics as possible explanations for variations of velocity in the back squat. Fourteen recreationally trained male subjects with experience in the back squat agreed to participate in the study (age = 25.0 ± 2.6 years, height = 178.9 ± 8.1 cm, body mass = 88.2 ± 15.8 kg). One-repetition maximums (1RM) were performed for each subject on force platforms with four linear position transducers attached to the barbell. …

Pre-Training Muscle Characteristics Of Subjects Who Are Obese Determine How Well Exercise Training Will Improve Their Insulin Responsiveness, Charles A. Stuart, Michelle L. Lee, Mark A. South, Mary E. A. Howell, Brian M. Cartwright, Michael W. Ramsey, Michael H. Stone

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Pre-training muscle characteristics of subjects who are obese determine how well exercise training will improve their insulin responsiveness. J Strength Cond Res 31(3): 798–808, 2017—Only half of prediabetic subjects who are obese who underwent exercise training without weight loss increased their insulin responsiveness. We hypothesized that those who improved their insulin responsiveness might have pretraining characteristics favoring a positive response to exercise training. Thirty nondiabetic subjects who were obese volunteered for 8 weeks of either strength training or endurance training. During training, subjects increased their caloric intake to prevent weight loss. Insulin responsiveness by euglycemic clamps and muscle fiber composition, …

Cell Free Dna As A Marker Of Training Status In Weightlifters, Jeremy A. Gentles, William G. Hornsby, Christine L. Coniglio, Andy R. Dotterweich, Jon A. Miller, Charles A. Stuart, Michael H. Stone

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The purpose of this investigation was to elucidate the changes in cf-DNA as it relates to fluctuations in resistance training workloads and intensities. The relationship between cell free DNA (cf-DNA), C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testosterone-cortisol ratio (T:C), body mass and body composition were also examined. Eight weightlifters (5 males and 3 females, age = 25 ± 3.5 yr, body mass = 88.3 ± 22.7 kg, height = 173.8 ±8.4 cm) volunteered to participate in this study. Venous blood samples, body mass and body composition were taken six times, each corresponding to the end of …

Analysis Of Changes In Muscle Architecture And Explosive Ability In Ncaa Division I Volleyball Players, Caleb D. Bazyler, Jacob R. Goodin, Conrad Rapp, Mark Disanto, Frank Smith, Michael H. Stone

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Abstract available in the 10th Annual Coaches and Sport Science College .

Utilizing Weightlifting For Cycling Performance, Nicholas J. Fiolo, Christopher B. Taber, Caleb D. Bazyler, Cody T. Haun, Robert Duncan, Aaron M. Thomas, Michael W. Ramsey, Michael H. Stone

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Abstract available in the 9th Annual Coaches and Sport Science College.

Insulin Resistance And Muscle Insulin Receptor Substrate-1 Serine Hyperphosphorylation, Charles A. Stuart, Mary E. A. Howell, Brian M. Cartwright, Melanie P. Mccurry, Michelle L. Lee, Michael W. Ramsey, Michael H. Stone

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Insulin resistance in metabolic syndrome subjects is profound in spite of muscle insulin receptor and insulin-responsive glucose transporter (GLUT4) expression being nearly normal. Insulin receptor tyrosine kinase phosphorylation of insulin receptor substrate-1 (IRS-1) at Tyr896 is a necessary step in insulin stimulation of translocation of GLUT4 to the cell surface. Serine phosphorylation of IRS-1 by some kinases diminishes insulin action in mice. We evaluated the phosphorylation status of muscle IRS-1 in 33 subjects with the metabolic syndrome and seventeen lean controls. Each underwent euglycemic insulin clamps and a thigh muscle biopsy before and after 8 weeks of either strength or …

The Effects Of Strength Training On Isometric Force Production Symmetry In Recreationally Trained Males, Caleb D. Bazyler, Christopher A. Bailey, Chieh-Ying Chiang, Kimitake Sato, Michael H. Stone

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Objectives: The purpose of this investigation was to determine what effect a bilateral strength training regimen has on isometric force production symmetry and if changes in force production symmetry can be accounted for by differences in pre-intervention strength levels. Design: Sixteen recreationally trained males (1-RM squat: 146.8 ± 23.0 kg.) were assigned to two groups for the 7-week training intervention: strong (S) and weak (W) based on pre-training squat isometric peak force allometrically scaled (IPFa) at 120° knee angle. Methods: Subjects completed a 7-week training intervention following a block-periodized model and were tested on measures of dynamic (1RM squat) and …

The Relationship Of Force Production Asymmetry And Performance In Athletes Of Different Strength Levels, Christopher A. Bailey, Caleb D. Bazyler, Chieh-Ying Chiang, Kimitake Sato, Michael H. Stone

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The purpose of this study was to evaluate the relationship between force production asymmetry and performance of athletes with differing strength levels in males and females. Collegiate athletes (n=129) from various sports were ranked according to isometric mid-thigh pull peak force and the top (‘strong’) and bottom (‘weak’) 25% were used for analysis. Symmetry index (SI) scores were calculated and correlated with their respective force-time characteristics using bivariate correlations. For the weaker males, several negative moderate correlations were observed; however, no statistically significant correlations were observed for the females in either group. These findings indicate that force production asymmetry is …

Differences In Semg Between Normal Squats And Accentuated Eccentric Loaded Squats In Competitive Collegiate Weightlifters, Christopher Macdonalds, Kimitake Sato, Christian Carter, Hugh Lamont, William Sands, Michael H. Stone, Michael Israetel, Jeremy A. Gentles, Jason Cholewa, John Garner, Michael Ramsey, Guy Hornsby

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The purpose of the present work was to compare the effect of accentuated eccentric loaded (AEL) squats to normally loaded (NOR) squats on surface measured muscle activation (sEMG) in competitive weightlifters. Eight experienced, competitive weightlifters (six males, two females) completed both an AEL and NOR squat session (seven days apart), comprised of nine sets of squats, and was identical to their normal scheduled training. sEMG data from the vastus medialis (VM), vastus lateralis (VL), and biceps femoris (BF) was collected (at 1000Hz) during the entirety of the concentric (CON) phases of the AEL and NOR sessions. RMANOVAs (set x session-type) …

The Efficacy Of Partial Squats On Measures Of Strength And Explosiveness: An Exploratory Study, Caleb D. Bazyler, Kimitake Sato, Craig A. Wassinger, Hugh S. Lamont, Michael H. Stone

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Abstract available in the 8th Annual Coaches and Sport Science College.

Insulin Responsiveness In Metabolic Syndrome After Eight Weeks Of Cycle Training, Charles A. Stuart, Mark A. South, Michelle L. Lee, Melanie P. Mccurry, Mary E. A. Howell, Michael W. Ramsey, Michael H. Stone

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Introduction Insulin resistance in obesity is decreased after successful diet and exercise. Aerobic exercise training alone was evaluated as an intervention in subjects with the metabolic syndrome.

Methods Eighteen nondiabetic, sedentary subjects, 11 with the metabolic syndrome, participated in 8 wk of increasing intensity stationary cycle training.

Results Cycle training without weight loss did not change insulin resistance in metabolic syndrome subjects or sedentary control subjects. Maximal oxygen consumption (V˙O2max), activated muscle AMP-dependent kinase, and muscle mitochondrial marker ATP synthase all increased. Strength, lean body mass, and fat mass did not change. The activated mammalian target of rapamycin was not …

Force Output Comparison Between Six U.S. Collegiate Athletic Teams., Caleb D. Bazyler, George Beckham, Howard Gray, Guy Hornsby, Ashley A. Kavanaugh, Christopher Macdonald, Satoshi Mizuguchi, Michael H. Stone, Michael H. Stone

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The aim of the study was to compare allometrically scaled peak force and the force at 250 ms between six U.S. collegiate sport teams using isometric mid-thigh pull. Ninety subjects performed maximum effort of isometric mid-thigh pull to measure force output. The data were averaged within the teams, and statistically compared between teams using one-way ANOVA (p=.01). Significant difference was found that men’s soccer and baseball produced higher allometrically scaled peak force, and men’s soccer, tennis, and baseball produced higher allometrically scaled force at 250 ms. The data indicates that not all sports possess similar strength characteristics because of the …

Relationships Between Jump Characteristics Of Collegiate Female Athletes Competing In Different Disciplines, Christopher J. Macdonalds, Hugh S. Lamont, John C. Garner, Jeremy A. Gentles, Ashley A. Kavanaugh, Michael H. Stone

ETSU Faculty Works

No abstract provided.

The Acute Effects Of Whole Body Vibration On Isometric Mid-Thigh Pull Performance, W. Guy Hornsby, Mark A. South, Ashley Kavanaugh, Andrew S. Layne, G. Gregory Haff, William A. Sands, Marco Cardinale, Michael W. Ramsey, Michael H. Stone

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Acute exposure to vibration has been suggested to produce transient increases in muscular strength (1,2,8), vertical jump displacement (4,8), and power output (2,6,7) recorded while performing various tasks. It has been hypothesized that the reported acute vibration induced increases in performance occur as a result of alterations in neuromuscular stimulation (1,3,4). Specifically, most studies have ascribed the observed improvements to the likeliness of Whole Body Vibration (WBV) in producing a “tonic vibration reflex” (TVR) in which the primary nerve endings of the Ia afferents of the muscle spindle are activated. This is thought to result in the excitation of the …