Publications by authors named "Alan Utter"

58 Publications

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Wrestling (2005-2006 Through 2013-2014) and National Collegiate Athletic Association Men's Wrestling (2004-2005 Through 2013-2014).

J Athl Train 2018 Dec;53(12):1143-1155

Injury Prevention Research Center, University of North Carolina at Chapel Hill.

Context: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of wrestling injury data.

Objective: To describe the epidemiology of injuries sustained in high school boys' wrestling in the 2005-2006 through 2013-2014 academic years and collegiate men's wrestling in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance.

Design: Descriptive epidemiology study.

Setting: Online injury surveillance from wrestling teams of high school boys (annual average = 100) and collegiate men (annual average = 11).

Patients Or Other Participants: Male wrestlers who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college.

Main Outcome Measure(s): Athletic trainers collected time-loss (≥24 hours) injuries and exposure data during this time period. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios with 95% confidence intervals, and injury proportions by body site and diagnosis were calculated.

Results: The High School Reporting Information Online documented 3376 time-loss injuries during 1 416 314 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 2387 time-loss injuries during 257 297 AEs. The total injury rate was higher in college than in high school (9.28 versus 2.38/1000 AEs; injury rate ratio = 3.89; 95% confidence interval = 3.69, 4.10). In high school, the most commonly injured body parts for both practices and competitions were the head/face (practices = 19.9%, competitions = 21.4%) and shoulder/clavicle (practices = 14.1%, competitions = 21.0%). In college, the most frequently injured body parts for both practices and competitions were the knee (practices = 16.7%, competitions = 30.4%) and head/face (practices = 12.1%, competitions = 14.6%).

Conclusions: Injury rates were higher in collegiate than in high school players, and the types of injuries sustained most often differed. Based on these results, continued study of primary and secondary prevention of injury in wrestlers across levels of competition is warranted.
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http://dx.doi.org/10.4085/1062-6050-154-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6365066PMC
December 2018

Effects of Continuous vs Discontinuous Aerobic Training on Cardiac Autonomic Remodeling.

Int J Sports Med 2019 Mar 10;40(3):180-185. Epub 2019 Jan 10.

HES, Appalachian State University, Boone, United States.

The aim of this study was to examine the cardiac autonomic nervous system differences following either continuous vs. discontinuous exercise in males and females. Forty-seven healthy male and female subjects (M=19, F=28; Age=36.95±13.79) underwent a baseline test for VO and tilt table testing. They were assigned to a one-month control period before returning to repeat the testing and then begin one month of either continuous aerobic treadmill work for 30 min at 70% peak heart rate (N=23) or 3 bouts of 10 min at 70% of peak heart rate with two 10-min break periods in between (N=24). Following exercise, both groups demonstrated a significant improvement in VO (p<0.001). Treatment differences were detected while tilted in continuous as a decreases in the percentage of instances within an hour that the normal sinus interval exceeds 50 ms (p=0.036) and in the high-frequency component (p=0.023). While supine, the discontinuous group saw reduction in heart rate (p=0.004), and an increase in high-frequency (p=0.018). These data suggest that for healthy people either continuous or discontinuous aerobic training is effective in improving measures of fitness; however discontinuous is better able to improve supine indices of vagal activity on heart rate variability.
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http://dx.doi.org/10.1055/s-0044-100921DOI Listing
March 2019

Effect of low dose, short-term creatine supplementation on muscle power output in elite youth soccer players.

J Int Soc Sports Nutr 2017 7;14. Epub 2017 Feb 7.

Department of Physical Education, Research Group on Metabolism, Nutrition and Strength Training, Curitiba, Brazil.

Background: To determine the effects of a low dose, short-term Creatine monohydrate (Cr) supplementation (0.03 g.kg.d during 14 d) on muscle power output in elite youth soccer players.

Methods: Using a two-group matched, double blind, placebo-controlled design, nineteen male soccer players (mean age = 17.0 ± 0.5 years) were randomly assigned to either Cr ( = 9) or placebo ( = 10) group. Before and after supplementation, participants performed a 30s Wingate Anaerobic Test (WAnT) to assess peak power output (PPO), mean power output (MPO), fatigue index (FI), and total work.

Results: There were significant increases in both PPO and MPO after the Cr supplementation period ( ≤ 0.05) but not the placebo period. There were also significant increases in total work, but not FI, after the Cr supplementation and placebo periods ( ≤ 0.05). Notably, there were differences in total work between the Cr and placebo groups after ( ≤ 0.05) but not before the 14 d supplementation period.

Conclusion: There is substantial evidence to indicate that a low-dose, short-term oral Cr supplementation beneficially affected muscle power output in elite youth soccer players.
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http://dx.doi.org/10.1186/s12970-017-0162-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5296953PMC
January 2018

Effect of exercise-induced dehydration on circulatory markers of oxidative damage and antioxidant capacity.

Appl Physiol Nutr Metab 2017 Jul 9;42(7):694-699. Epub 2017 Feb 9.

a Department of Health and Exercise Science, Appalachian State University, 111 Rivers Street, Boone, NC USA.

Dehydration is a common event associated with exercise. However, few studies have examined the effects of dehydration on plasma redox status in humans. Eighty-two athletes were recruited and baseline anthropometrics and blood samples were obtained. Athletes then engaged in a dehydration protocol, training until 3% of preweight body mass was lost. Athletes returned to the lab and had postdehydration blood collected. Athletes then consumed an isotonic drink until pre-exercise body weight was reestablished. Blood was then recollected (1 h post full rehydration (PFR)). Samples were centrifuged and the plasma snap frozen in liquid nitrogen and stored at -80 °C. Lipid and protein oxidative stress was determined by measuring F-isoprostanes and protein carbonyls (PC), respectively. Antioxidant capacity was determined by the ferric reducing ability of plasma (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. Plasma osmolality was determined using an osmometer. Statistical analysis utilized a 1-way ANOVA with posthoc testing. Values are reported as mean ± SD. Plasma osmolality was significantly elevated immediately postdehydration (p ≤ 0.001) but decreased to baseline at PFR. Plasma TEAC increased immediately postdehydration and at PFR (p ≤ 0.001). FRAP increased immediately postdehydration (p ≤ 0.001) and decreased to below baseline at PFR (p ≤ 0.05). Conversely, F-isoprostanes declined significantly from baseline to immediately postdehydration and then significantly rose at PFR (p ≤ 0.001), whereas PC declined at PFR (p ≤ 0.01). This study indicates that dehydration and exercise cause a significant increase in plasma osmolality and antioxidant potential immediately postexercise. We propose dehydration significantly elevates antioxidant concentration which suppresses F-isoprostanes and PC.
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http://dx.doi.org/10.1139/apnm-2016-0701DOI Listing
July 2017

Differential Effects of Continuous Versus Discontinuous Aerobic Training on Blood Pressure and Hemodynamics.

J Strength Cond Res 2018 Jan;32(1):97-104

Department of Health and Exercise Science, Vascular Biology and Autonomic Studies Laboratory, College of Health Sciences, Appalachian State University, Boone, North Carolina.

Landram, MJ, Utter, AC, Baldari, C, Guidetti, L, McAnulty, SR, and Collier, SR. Differential effects of continuous versus discontinuous aerobic training on blood pressure and hemodynamics. J Strength Cond Res 32(1): 97-104, 2018-The purpose of this study was to compare the hemodynamic, arterial stiffness, and blood flow changes after 4 weeks of either continuous or discontinuous aerobic exercise in adults. Forty-seven subjects between the ages of 18 and 57 were recruited for 1 month of either continuous aerobic treadmill work for 30 minutes at 70% max heart rate or 3 bouts of 10 minutes of exercise at 70% of max heart rate with two 10 minutes break periods in between, totaling 30 minutes of aerobic work. After exercise, both continuous (CON) and discontinuous (DIS) groups demonstrated a significant improvement in maximal oxygen uptake (V[Combining Dot Above]O2max, CON 35.39 ± 1.99 to 38.19 ± 2.03; DIS 36.18 ± 1.82 to 39.33 ± 1.75), heart rate maximum (CON 183.5 ± 3.11 to 187.17 ± 3.06; DIS 179.06 ± 2.75 to 182 ± 2.61), decreases in systolic blood pressure (CON 119 ± 1.82 to 115.11 ± 1.50; DIS 117.44 ± 1.90 to 112.67 ± 1.66), diastolic blood pressure (CON 72.56 ± 1.65 to 70.56 ± 1.06; DIS 71.56 ± 1.59 to 69.56 ± 1.43), augmentation index (CON 17.17 ± 2.17 to 14.9 ± 1.92; DIS 19.71 ± 2.66 to 13.91 ± 2.46), central pulse wave velocity (CON 8.29 ± 0.32 to 6.92 ± 0.21; DIS 7.85 ± 0.30 to 6.83 ± 0.29), peripheral pulse wave velocity (CON 9.49 ± 0.35 to 7.72 ± 0.38; DIS 9.11 ± 0.37 to 7.58 ± 0.47), and significant increases in average forearm blood flow (CON 4.06 ± 0.12 to 4.34 ± 0.136; DIS 4.26 ± 0.18 to 4.53 ± 0.15), peak forearm blood flow (FBF) after reactive hyperemia (CON 28.45 ± 0.094 to 29.96 ± 0.45; DIS 29.29 ± 0.46 to 30.6 ± 0.38), area under the curve (AUC) of FBF (CON 28.65 ± 1.77 to 30.4 ± 1.08; DIS 30.52 ± 1.9 to 31.67 ± 1.44), and AUC peak FBF after reactive hyperemia (CON 222.3 ± 5.68 to 231.95 ± 4.42; DIS 230.81 ± 6.91 to 237.19 ± 5.39). These data suggest that for healthy people either 4 weeks of continuous or discontinuous aerobic training is effective in improving measures of fitness and vascular health.
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http://dx.doi.org/10.1519/JSC.0000000000001661DOI Listing
January 2018

The effects of strength training on cognitive performance in elderly women.

Clin Interv Aging 2016 1;11:749-54. Epub 2016 Jun 1.

Research Group on Metabolism, Nutrition and Strength Training, Department of Physical Education, Federal University of Parana, Curitiba, Brazil; Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.

Aging is a degenerative process marked by recognized functional, physiological, and metabolic impairments, such as dynapenia and diminished cognitive capacity. Therefore, the search for innovative strategies to prevent/delay these physiological and cognitive disorders is essential to guarantee the independence and life quality of an elderly population. The aim of this work is to verify the effect of a 12-week resistance exercise program on the general physical aptitude and cognitive capacities of elderly and sedentary women. Twenty-nine women (65.87±5.69 years) were divided into two groups. The control group was composed of eight elderly women who met the same inclusion criteria of the study and the strength training group was composed of 29 elderly women who were subjected to a resistance exercise program defined by 12 upper and lower limb exercises combined in 3×10 repetitions with 1-minute interval between repetitions and two resting minutes between exercises (three times/week). Weight loads were fixed between 60% and 75% of the apparent 1 repetition maximum, which was estimated by the test of 10 maximum repetitions. The direct curl was performed for upper body strength evaluation with 2.3 kg dumbbells for 30 seconds, whereas the chair test was used for lower body evaluation (total sit-stand movements in 30 seconds). The cognitive capacities of subjects were evaluated by "The Montreal Cognitive Assessment" questionnaire. After 12 weeks, the elderly group showed significant increases in the average upper body strength (58%), lower body strength (68%), and cognitive capacity (19%). The present study demonstrated that regular resistance exercises could provide significant gains on the upper and lower body strength concomitant to positive improvements on cognitive capacities of elderly women, bringing enhanced life quality.
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http://dx.doi.org/10.2147/CIA.S102126DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896469PMC
February 2017

Validity of Urine Specific Gravity When Compared With Plasma Osmolality as a Measure of Hydration Status in Male and Female NCAA Collegiate Athletes.

J Strength Cond Res 2016 Aug;30(8):2219-25

Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina.

Sommerfield, LM, McAnulty, SR, McBride, JM, Zwetsloot, JJ, Austin, MD, Mehlhorn, JD, Calhoun, MC, Young, JO, Haines, TL, and Utter, AC. Validity of urine specific gravity when compared with plasma osmolality as a measure of hydration status in male and female NCAA collegiate athletes. J Strength Cond Res 30(8): 2219-2225, 2016-The purpose of this study was to evaluate the response of urine specific gravity (Usg) and urine osmolality (Uosm) when compared with plasma osmolality (Posm) from euhydration to 3% dehydration and then a 2-hour rehydration period in male and female collegiate athletes. Fifty-six National Collegiate Athletic Association (NCAA) wrestlers (mean ± SEM); height 1.75 ± 0.01 m, age 19.3 ± 0.2 years, and body mass (BM) 78.1 ± 1.8 kg and 26 NCAA women's soccer athletes; height 1.64 ± 0.01 m, age 19.8 ± 0.3 years, and BM 62.2 ± 1.2 kg were evaluated. Hydration status was obtained by measuring changes in Posm, Uosm, Usg, and BM. Male and female subjects dehydrated to achieve an average BM loss of 2.9 ± 0.09% and 1.9 ± 0.03%, respectively. Using the medical diagnostic decision model, the sensitivity of Usg was high in both the hydrated and dehydrated state for males (92%) and females (80%). However, the specificity of Usg was low in both the hydrated and dehydrated states for males (10 and 6%, respectively) and females (29 and 40%, respectively). No significant correlations were found between Usg and Posm during either the hydrated or dehydrated state for males or females. Based on these results, the use of Usg as a field measure of hydration status in male and female collegiate athletes should be used with caution. Considering that athletes deal with hydration status on a regular basis, the reported low specificity of Usg suggests that athletes could be incorrectly classified leading to the unnecessary loss of competition.
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http://dx.doi.org/10.1519/JSC.0000000000001313DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4912946PMC
August 2016

Acute Sodium Ingestion Before Exercise Increases Voluntary Water Consumption Resulting In Preexercise Hyperhydration and Improvement in Exercise Performance in the Heat.

Int J Sport Nutr Exerc Metab 2015 Oct 26;25(5):456-62. Epub 2015 Mar 26.

Dept. of Kinesiology, University of Texas of the Permian Basin, Odessa, TX.

Dehydration has been shown to hinder performance of sustained exercise in the heat. Consuming fluids before exercise can result in hyperhydration, delay the onset of dehydration during exercise and improve exercise performance. However, humans normally drink only in response to thirst, which does not result in hyperhydration. Thirst and voluntary fluid consumption have been shown to increase following oral ingestion or infusion of sodium into the bloodstream. We measured the effects of acute sodium ingestion on voluntary water consumption and retention during a 2-hr hydration period before exercise. Subjects then performed a 60-min submaximal dehydration ride (DR) followed immediately by a 200 kJ performance time trial (PTT) in a warm (30 °C) environment. Water consumption and retention during the hydration period was greater following sodium ingestion (1380 ± 580 mL consumed, 821 ± 367 ml retained) compared with placebo (815 ± 483 ml consumed, 244 ± 402 mL retained) and no treatment (782 ± 454 ml consumed, 148 ± 289 mL retained). Dehydration levels following the DR were significantly less after sodium ingestion (0.7 ± 0.6%) compared with placebo (1.3 ± 0.7%) and no treatment (1.6 ± 0.4%). Time to complete the PTT was significantly less following sodium consumption (773 ± 158 s) compared with placebo (851 ± 156 s) and no treatment (872 ± 190 s). These results suggest that voluntary hyperhydration can be induced by acute consumption of sodium and has a favorable effect on hydration status and performance during subsequent exercise in the heat.
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http://dx.doi.org/10.1123/ijsnem.2014-0212DOI Listing
October 2015

Effect of resveratrol and quercetin supplementation on redox status and inflammation after exercise.

Appl Physiol Nutr Metab 2013 Jul 8;38(7):760-5. Epub 2013 Mar 8.

Department of Nutrition and Health Care Management, Appalachian State University, Boone, NC 28608, USA.

Resveratrol and quercetin function as antioxidants and anti-inflammatories in vitro, but these mechanisms have been minimally examined in combination in exercising humans. The purpose of this investigation was to examine supplementation as a countermeasure against oxidative stress and inflammation in response to exercise. Fourteen athletes were randomly assigned, in a double-blind crossover design, to a resveratrol and quercetin combination (RQ) (120 mg resveratrol and 225 mg quercetin for 6 days and 240 mg resveratrol and 450 mg quercetin on day 7 just prior to exercise) or to placebo (P). There was a 1-week washout between trials. Blood was taken at baseline, pre-exercise, immediately after exercise, and 1 h after exercise. Plasma was analyzed for oxidative stress (F2-isoprostanes and protein carbonyls), antioxidant capacity (ferric-reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), oxygen radical absorptive capacity (ORAC)), and inflammation (cytokine interleukin (IL)-8 and C-reactive protein (CRP)). Statistical design utilized a 2 × 3 ANOVA and Student's t test. Pre-exercise values were not different from baseline for any measure. The postexercise increase in F2-isoprostanes was significantly less (p = 0.039 interaction) with RQ (68%) than with P (137%). Protein carbonyls, FRAP, ORAC, and TEAC significantly increased after exercise but were not affected by treatment. IL-8 and CRP increased significantly immediately after exercise but were not affected by treatment. These data indicate that RQ significantly reduces exercise-induced lipid peroxidation without associated changes in inflammation or plasma antioxidant status.
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http://dx.doi.org/10.1139/apnm-2012-0455DOI Listing
July 2013

Validity of COSMED's quark CPET mixing chamber system in evaluating energy metabolism during aerobic exercise in healthy male adults.

Res Sports Med 2013 ;21(2):136-45

Department of Health, Leisure, and Exercise Science, Human Performance Lab, Appalachian State University, Boone, North Carolina 28608, USA.

This study validated the accuracy of COSMED's Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system in measuring metabolic factors during maximal, graded exercise testing. Subjects included 32 physically active men between the ages of 18 and 34 years. During the first test session, subjects were measured for maximal oxygen consumption twice (15 min separation) with the CPET and Douglas bag systems (random order). During the second test session, subjects exercised through four stages of the Bruce treadmill protocol with measurement by the CPET and Douglas bag systems (random order) during steady state at the end of each 3-minute stage. Statistical analysis using a 2 (systems) x 5 (time) repeated measures ANOVA showed that the pattern of change in VO2, VCO2, VE, FeO2, FeCO2, and RER did not differ significantly between CPET and Douglas bag systems. This validation study indicates that the CPET mixing chamber system provides valid metabolic measurements that compare closely with the Douglas bag system during aerobic exercise.
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http://dx.doi.org/10.1080/15438627.2012.757227DOI Listing
October 2013

Dehydration and acute weight gain in mixed martial arts fighters before competition.

J Strength Cond Res 2013 May;27(5):1322-6

Department of Health, Leisure, and Exercise Science; Appalachian State University, Boone, North Carolina, UK.

The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration.
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http://dx.doi.org/10.1519/JSC.0b013e31828a1e91DOI Listing
May 2013

Effect of cluster set configurations on power clean technique.

J Sports Sci 2013 5;31(5):488-96. Epub 2012 Nov 5.

Neuromuscular and Biomechanics Laboratory, Department of Health, Leisure and Exercise Science, Appalachian State University, Boone, North Carolina, USA.

The purpose of this investigation was to examine the effects of cluster set configurations on power clean technique. Ten male, recreational weightlifters performed three sets of six repetitions at 80% of one repetition max with 0 (P0), 20 (P20) or 40 seconds (P40) inter-repetition rest. During the first and second set of P0, the catch and first pull were in a more forward position during repetition 6 as compared to repetition 1, respectively. During the second set of P40, differences in horizontal displacement were found between repetitions 1 and 6 for the second pull and the loop. During the third set of P40, differences in horizontal displacement were found between repetitions 1 and 6 for the first pull, transition, and beginning of the second pull. No differences in horizontal displacement were found between repetitions 1 and 6 during P20. During each set of P0, vertical displacement decreased between repetitions 1 and 6 (1.02 ± 0.07 m vs. 0.94 ± 0.06 m; Mean ± s). Cluster set configurations led to the maintenance of vertical displacement throughout all sets. The results demonstrate cluster set configurations with greater than 20 seconds inter-repetition rest maintain weightlifting technique to a greater extent than a traditional set configuration.
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http://dx.doi.org/10.1080/02640414.2012.736633DOI Listing
August 2013

Effect of interrepetition rest on power output in the power clean.

J Strength Cond Res 2012 Apr;26(4):883-9

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina, USA.

The effect of interrepetition rest (IRR) periods on power output during performance of multiple sets of power cleans is unknown. It is possible that IRR periods may attenuate the decrease in power output commonly observed within multiple sets. This may be of benefit for maximizing improvements in power with training. This investigation involved 10 college-aged men with proficiency in weightlifting. The subjects performed 3 sets of 6 repetitions of power cleans at 80% of their 1 repetition maximum with 0 (P0), 20 (P20), or 40 seconds (P40) of IRR. Each protocol (P0, P20, P40) was performed in a randomized order on different days each separated by at least 72 hours. The subjects performed the power cleans while standing on a force plate with 2 linear position transducers attached to the bar. Peak power, force, and velocity were obtained for each repetition and set. Peak power significantly decreased by 15.7% during P0 in comparison with a decrease of 5.5% (R1: 4,303 ± 567 W, R6: 4,055 ± 582 W) during P20 and a decrease of 3.3% (R1: 4,549 ± 659 W, R6: 4,363 ± 476 W) during P40. Peak force significantly decreased by 7.3% (R1: 2,861 ± 247 N, R6: 2,657 ± 225 N) during P0 in comparison with a decrease of 2.7% (R1: 2,811 ± 327 N, R6: 2,730 ± 285 N) during P20 and an increase of 0.4% (R1: 2,861 ± 323 N, R6: 2,862 ± 280 N) during P40. Peak velocity significantly decreased by 10.2% (R1: 1.97 ± 0.15 m·s(-1), R6: 1.79 ± 0.11 m·s(-1)) during P0 in comparison with a decrease of 3.8% (R1: 1.89 ± 0.13 m·s(-1), R6: 1.82 ± 0.12 m·s(-1)) during P20 and a decrease of 1.7% (R1: 1.93 ± 0.17 m·s(-1), R6: 1.89 ± 0.14 m·s(-1)) during P40. The results demonstrate that IRR periods allow for the maintenance of power in the power clean during a multiple set exercise protocol and that this may have implications for improved training adaptations.
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http://dx.doi.org/10.1519/JSC.0b013e3182474370DOI Listing
April 2012

Effect of inter-repetition rest on ratings of perceived exertion during multiple sets of the power clean.

Eur J Appl Physiol 2012 Aug 4;112(8):3141-7. Epub 2012 Jan 4.

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA.

The purpose of this study was to examine the effects of inter-repetition rest (IRR) on ratings of perceived exertion (RPE) in the power clean exercise in a multiple set protocol using peak power as an indication of fatigue. Ten resistance-trained males participated in four testing sessions which consisted of determination of a one repetition maximum (1RM) in the power clean exercise (session 1) and performance of three sets of six repetitions at 80% of 1RM with 0 (P0), 20 (P20), or 40 s (P40) IRR (sessions 2-4). Fatigue during all three conditions was indicated by a significant decrease in power of 9.0% (P0), 3.0% (P20) and 2.1% (P40), respectively. Significant difference in the rate of power decrease in P40 indicates less fatigue in comparison to P0 and P20. P40 resulted in a significantly lower RPE compared to P0 and P20 (7.43 ± 0.34, 6.46 ± 0.47, and 5.30 ± 0.55, respectively). RPE increased significantly (p ≤ 0.01) within each set (5.26 ± 0.37, 6.46 ± 0.44, and 7.46 ± 0.53; sets 1, 2, and 3, respectively). Significant difference in average RPE between the conditions indicates that RPE is not a determinant of intensity (% of 1RM) but the rate of fatigue (decreases in peak power). In addition, the fact that RPE increased between sets 1, 2 and 3 during all conditions support the same conclusion. The results demonstrate that increasing IRR in power clean training decreases the perception of effort and is inversely related to the rate of fatigue.
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http://dx.doi.org/10.1007/s00421-011-2300-xDOI Listing
August 2012

Effect of blueberry ingestion on natural killer cell counts, oxidative stress, and inflammation prior to and after 2.5 h of running.

Appl Physiol Nutr Metab 2011 Dec 23;36(6):976-84. Epub 2011 Nov 23.

Department of Nutrition and Health Care Management, Appalachian State University, Boone, NC 28608, USA.

Blueberries are rich in antioxidants known as anthocyanins, which may exhibit significant health benefits. Strenous exercise is known to acutely generate oxidative stress and an inflammatory state, and serves as an on-demand model to test antioxidant and anti-inflammatory compounds. The purpose of this study was to examine whether 250 g of blueberries per day for 6 weeks and 375 g given 1 h prior to 2.5 h of running at ∼72% maximal oxygen consumption counters oxidative stress, inflammation, and immune changes. Twenty-five well-trained subjects were recruited and randomized into blueberry (BB) (N = 13) or control (CON) (N = 12) groups. Blood, muscle, and urine samples were obtained pre-exercise and immediately postexercise, and blood and urine 1 h postexercise. Blood was examined for F₂-isoprostanes for oxidative stress, cortisol, cytokines, homocysteine, leukocytes, T-cell function, natural killer (NK), and lymphocyte cell counts for inflammation and immune system activation, and ferric reducing ability of plasma for antioxidant capacity. Muscle biopsies were examined for glycogen and NFkB expression to evaluate stress and inflammation. Urine was tested for modification of DNA (8-OHDG) and RNA (5-OHMU) as markers of nucleic acid oxidation. A 2 (treatment) × 3 (time) repeated measures ANOVA was used for statistical analysis. Increases in F₂-isoprostanes and 5-OHMU were significantly less in BB and plasma IL-10 and NK cell counts were significantly greater in BB vs. CON. Changes in all other markers did not differ. This study indicates that daily blueberry consumption for 6 weeks increases NK cell counts, and acute ingestion reduces oxidative stress and increases anti-inflammatory cytokines.
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http://dx.doi.org/10.1139/h11-120DOI Listing
December 2011

The validity of multifrequency bioelectrical impedance measures to detect changes in the hydration status of wrestlers during acute dehydration and rehydration.

J Strength Cond Res 2012 Jan;26(1):9-15

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina, USA.

The objective of this study was to examine the validity of multifrequency direct segmental bioelectrical impedance analysis (DSM-BIA) measures to detect changes in the hydration status of wrestlers after they underwent 3% acute dehydration and a 2-hour rehydration period. Fifty-six National Collegiate Athletic Association wrestlers: (mean ± SEM); age 19.5 ± 0.2 years, height 1.73 ± 0.01 m, and body mass (BM) 82.5 ± 2.3 kg were tested in euhydrated, dehydrated (-3.5%), and 2-hour rehydration conditions using DSM-BIA to detect the changes in hydration status. The hydration status was quantified by measuring the changes in plasma osmolality (P(osm)), urine osmolality (Uosm), urine specific gravity (U(sg)), BM, and weighted segmental impedance at frequencies of 5, 20, 50, 100, and 500 kHz. Weighted segmental impedance significantly increased after a 3.5% reduction in the body weight for all the 5 frequencies evaluated, but it did not return to baseline at 2-hour rehydration. P(osm) (303 ± 0.6 mOsm·L(-1)), Uosm (617 ± 47 mOsm·L(-1)), and U(sg) (1.017 ± 0.001) all significantly increased at postdehydration and returned to baseline at 2-hour rehydration. Estimations of extracellular water were significantly different throughout the trial, but there were no significant changes in the estimations of the total body water or intracellular water. The results of this study demonstrate the potential use of DSM-BIA as a field measure to assess the hydration status of wrestlers for the purpose of minimal weight certification before the competitive season. When employing DSM-BIA to assess the hydration status, the results indicated that the changes in weighted segmental impedance at the frequencies evaluated (5, 20, 50, 100, and 500 kHz) are sensitive to acute changes in dehydration but lag behind changes in the standard physiological (plasma and urinary) markers of hydration status after a 2-hour rehydration period.
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http://dx.doi.org/10.1519/JSC.0b013e318238ea51DOI Listing
January 2012

Validation of the OMNI-cycle scale of perceived exertion in the elderly.

J Aging Phys Act 2011 Jul;19(3):214-24

Dept. of Health Sciences, University of Rome Foro Italico, Rome, Italy.

This study examined the concurrent and construct validity of the OMNI-Cycle Rating of Perceived Exertion (RPE) Scale, using elderly men and women. Seventy-six participants performed a load-incremented cycle-ergometer exercise test. Concurrent validity was determined by correlating OMNI-RPE responses with oxygen uptake, relative peak oxygen uptake, pulmonary ventilation, heart rate, respiratory rate, and respiratory-exchange ratio during a load-incremented cycle-ergometer protocol. Construct validity was established by correlating RPE derived from the OMNI-Cycle Scale with RPE from the Borg (6-20) Scale. Multilevel, mixed linear-regression models indicated that OMNI-RPE distributed as a significant (p < .05) positive linear function (r = .81-.92) for all physiological measures. OMNI-RPE was positively (p < .01) and linearly related to Borg-RPE in elderly men (r = .97) and women (r = .96). This study demonstrates both concurrent and construct validity of the OMNI-Cycle RPE Scale. These findings support the use of this scaling metric with elderly men and women to estimate RPE during cycle-ergometer exercise.
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http://dx.doi.org/10.1123/japa.19.3.214DOI Listing
July 2011

National Athletic Trainers' Association position statement: safe weight loss and maintenance practices in sport and exercise.

J Athl Train 2011 May-Jun;46(3):322-36

Duquesne University, Pittsburgh, PA, USA.

Objective: To present athletic trainers with recommendations for safe weight loss and weight maintenance practices for athletes and active clients and to provide athletes, clients, coaches, and parents with safe guidelines that will allow athletes and clients to achieve and maintain weight and body composition goals.

Background: Unsafe weight management practices can compromise athletic performance and negatively affect health. Athletes and clients often attempt to lose weight by not eating, limiting caloric or specific nutrients from the diet, engaging in pathogenic weight control behaviors, and restricting fluids. These people often respond to pressures of the sport or activity, coaches, peers, or parents by adopting negative body images and unsafe practices to maintain an ideal body composition for the activity. We provide athletic trainers with recommendations for safe weight loss and weight maintenance in sport and exercise. Although safe weight gain is also a concern for athletic trainers and their athletes and clients, that topic is outside the scope of this position statement.

Recommendations: Athletic trainers are often the source of nutrition information for athletes and clients; therefore, they must have knowledge of proper nutrition, weight management practices, and methods to change body composition. Body composition assessments should be done in the most scientifically appropriate manner possible. Reasonable and individualized weight and body composition goals should be identified by appropriately trained health care personnel (eg, athletic trainers, registered dietitians, physicians). In keeping with the American Dietetics Association (ADA) preferred nomenclature, this document uses the terms registered dietitian or dietician when referring to a food and nutrition expert who has met the academic and professional requirements specified by the ADA's Commission on Accreditation for Dietetics Education. In some cases, a registered nutritionist may have equivalent credentials and be the commonly used term. All weight management and exercise protocols used to achieve these goals should be safe and based on the most current evidence. Athletes, clients, parents, and coaches should be educated on how to determine safe weight and body composition so that athletes and clients more safely achieve competitive weights that will meet sport and activity requirements while also allowing them to meet their energy and nutritional needs for optimal health and performance.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3419563PMC
http://dx.doi.org/10.4085/1062-6050-46.3.322DOI Listing
January 2012

Validation of the Italian version of the OMNI Scale of Perceived Exertion in a sample of Italian-speaking adults.

Percept Mot Skills 2011 Feb;112(1):201-10

Department of Health Sciences, Unit of Exercise and Sports Sciences, University of Rome "Foro Italico," Piazza Lauro De Bosis, 15, 00135 Rome, Italy.

The purpose was to examine whether the translation of verbal descriptors from English to Italian affects the validity of the OMNI Scale of Perceived Exertion. 82 people for whom Italian was the primary language performed an orintation trial and a maximal graded exercise test on a cycle ergometer. Ratings of perceived exertion for the overall body and physiological responses were measured during each exercise stage. Significant correlations were found between perceptual responses of the Italian version of the OMNI Cycle Scale of Perceived Exertion and oxygen uptake, pulmonary ventilation, heart rate, respiratory rate, and respiratory exchange ratio responses to a maximal graded exercise test on a cycle ergometer. These findings indicate that the Italian version of the OMNI Scale of Perceived Exertion gives a valid estimate of effort during cycle ergometer exercise.
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http://dx.doi.org/10.2466/06.07.13.27.PMS.112.1.201-210DOI Listing
February 2011

Evaluation of ultrasound velocity to assess the hydration status of wrestlers.

J Strength Cond Res 2010 Jun;24(6):1451-7

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina, USA.

The objective of this study was to evaluate the utility of ultrasound velocity (UV) to detect changes in the hydration status of wrestlers after undergoing acute dehydration and a 2-hour rehydration period. Forty-seven NCAA wrestlers (mean+/-SEM); age 19.1+/-0.2 years, height 1.73+/-0.1 m, body mass (BM) 79.4+/-2.4 kg were tested in euhydrated, dehydrated, and a 2-hours rehydrated conditions. Hydration status was quantified by measuring changes in plasma osmolarity (Posm), urine osmolarity (Uosm), urine specific gravity (Usg), and BM. Ultrasound velocity was measured at 1 MHz using 1.5-microsecond duration tone burst in the soleus muscle. Significant changes (p<0.001) in UV during periods of dehydration (BM change=-3.6+/-0.14%) (UV=+2.18 m.s) and rehydration (BM change=+2.8+/-0.12%) (UV=-2.89 m.s) were found. Significant main effects (p<0.001) were also found for Usg, Uosm, and Posm during dehydration. The change in Posm from the 1 to 2-hour rehydration time period significantly correlated to the change in UV during the same time period (r=0.27, p<0.001). This study demonstrates that changes in UV correspond to the changes of Posm, Usg, Uosm, and BM during acute dehydration and rehydration in collegiate wrestlers. The use of ultrasound measures may have potential application as an alternative field-based method to assess the hydration status of collegiate wrestlers although future research is warranted.
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http://dx.doi.org/10.1519/JSC.0b013e3181d82d26DOI Listing
June 2010

Effects of rooibos tea, bottled water, and a carbohydrate beverage on blood and urinary measures of hydration after acute dehydration.

Res Sports Med 2010 Apr;18(2):85-96

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina 28608, USA.

Rooibos tea contains polyphenol antioxidants, including flavonoids and phenolic acids that are potent free radical scavengers and has purported benefits for accelerated rehydration. The objective was to evaluate the effects of three different drinks (rooibos tea, bottled water, and a carbohydrate beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-three athletes were recruited and followed a randomized, cross-over design with three different study arms comparing the effectiveness of rooibos tea, carbohydrate beverage (6% or 60 grams l(-1)), or bottled water (placebo) in promoting rehydration after a 3% reduction in body mass. Urine specific gravity (U(sg)) urine (U(osm)) and plasma osmolarity (P(osm)), and plasma volume were measured pre- and post dehydration and at 1-h after rehydration. Statistical analyses utilized a 3 (conditions) x 3 (times) repeated measures analysis of variance to test main effects. Significant interaction effects were found for P(osm) and U(osm), both of which remained below basleline after 1-h rehydration in the rooibos tea and water trials. No significant interaction effects were found for either urine U(sg) or plasma volume shift. The findings of this study demonstrate that rooibos tea was no more effective in promoting rehydration than plain water, with significant changes being found for P(osm) and U(osm) in the carbohydrate/electrolyte solution, in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1-h when consuming 100% of their body weight loss.
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http://dx.doi.org/10.1080/15438620903321102DOI Listing
April 2010

Quercetin's effect on cycling efficiency and substrate utilization.

Appl Physiol Nutr Metab 2009 Dec;34(6):993-1000

Department of Health and Human Perfomance, University of Montana, Missoula, MT 59812, USA.

Previous evidence suggests that quercetin supplementation increases performance in humans. We examined the effects of 3 weeks of quercetin supplementation on fuel utilization, gross efficiency (GE), and perceived effort during 3 h of cycling over 3 successive days. Forty cyclists were randomized into quercetin and placebo groups and tested for maximal oxygen consumption (53.2 +/- 1.2 and 54.7 +/- 1.1 mL.kg(-1).min(-1)). For 3 weeks following maximal oxygen consumption testing, subjects supplemented either 1000 mg.day(-1) quercetin or placebo during normal training. Following supplementation, subjects cycled at 57% maximum power for 3 h, on 3 successive days, using their own bicycles fitted to CompuTrainer Pro Model trainers (RacerMate, Seattle, Wash.). Metabolic measurements were taken every 30 min for each 3-h ride. Muscle biopsies obtained from the vastus lateralis immediately pre-exercise and postexercise on days 1 and 3 were analyzed for muscle glycogen content. Power output remained constant for all 3 exercise trials, but significant decreases over time were measured for GE, cadence, respiratory exchange ratio, blood glucose, and muscle glycogen. Significant increases were measured for heart rate and volume of oxygen consumption over time. No quercetin treatment effect was observed for any of the outcome measures in this study. These data indicate that GE is reduced during an exhausting 3-h bout of exercise. However, quercetin did not significantly affect any outcomes in these already well-trained subjects.
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http://dx.doi.org/10.1139/H09-099DOI Listing
December 2009

Evaluation of multifrequency bioelectrical impedance analysis in assessing body composition of wrestlers.

Med Sci Sports Exerc 2010 Feb;42(2):361-7

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA.

Purpose: To evaluate the accuracy of multifrequency bioelectrical impedance analysis (MFBIA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state.

Methods: Body composition was determined by MFBIA, HW, and three-site SK in 72 high school wrestlers (mean +/- SD; age = 15.3 +/- 1.4 yr, height = 1.71 +/- 0.08 m, body mass = 67.3 +/- 13.4 kg). Hydration state was quantified by evaluating urine specific gravity.

Results: There were no significant differences for estimated FFM between MFBIA (57.2 +/- 9.5 kg) and HW (57.0 +/- 10.1 kg) or SK (56.4 +/- 8.8 kg). The SEE for FFM with HW as the reference method were 2.73 kg for MFBIA and 2.66 kg for SK. Correlations were found for FFM between HW and MFBIA (r = 0.96, P < 0.001) and between HW and SK (r = 0.97, P < 0.001). A systematic bias was found for MFBIA because the difference between MFBIA and HW correlated with the FFM average of the two methods (r = -0.22, P < 0.001). A bias was also seen between SK and HW and correlated with the FFM average (r = -0.47, P < 0.001).

Conclusions: This study demonstrates that MFBIA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. MFBIA is an attractive assessment tool, easy to use, and may be considered as an alternative field-based method of estimating the FFM of high school wrestlers.
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http://dx.doi.org/10.1249/MSS.0b013e3181b2e8b4DOI Listing
February 2010

Effects of commercially formulated water on the hydration status of dehydrated collegiate wrestlers.

J Strength Cond Res 2009 Nov;23(8):2210-6

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina, USA.

The objective of this study was to evaluate the effects of three different drinks (commercially formulated water, bottled water, and a carbohydrate-electrolyte beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-one athletes were recruited to perform a randomized, crossover study comparing the effectiveness of commercially formulated water, carbohydrate-electrolyte (6% or 60 g L(-1)), or regular bottled water (placebo) in promoting rehydration after a 3% reduction in body mass. Urine specific gravity (U(sg)), urine osmolarity (U(osm)), plasma osmolarity (P(osm)), and plasma volume were measured pre- and post-dehydration and at 1 hour after rehydration. Statistical analyses used a 3 (conditions) x 3 (times) repeated measures analysis of variance. Significant (p < 0.01) interactions were found for P(osm), U(osm), and U(sg). P(osm) returned to baseline levels and U(osm) remained in a lower balance after 1 hour of rehydration in the trials of the commercially formulated water and regular bottled water. No significant interactions were found for plasma volume shift. The findings of this study demonstrate that the commercially formulated water was no more effective in promoting rehydration than either a carbohydrate-electrolyte solution or plain water in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1 hour when consuming 100% of their body weight loss.
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http://dx.doi.org/10.1519/JSC.0b013e3181bac56eDOI Listing
November 2009

Successive bouts of cycling stimulates genes associated with mitochondrial biogenesis.

Eur J Appl Physiol 2009 Nov 6;107(4):419-27. Epub 2009 Aug 6.

Department of Health and Human Performance, University of Montana, Missoula, MT 59812, USA.

Exercise increases mRNA for genes involved in mitochondrial biogenesis and oxidative enzyme capacity. However, little is known about how these genes respond to consecutive bouts of prolonged exercise. We examined the effects of 3 h of intensive cycling performed on three consecutive days on the mRNA associated with mitochondrial biogenesis in trained human subjects. Forty trained cyclists were tested for VO(2max) (54.7 +/- 1.1 ml kg(-1) min(-1)). The subjects cycled at 57% watts(max) for 3 h using their own bicycles on CompuTrainer Pro Model trainers (RacerMate, Seattle, WA) on three consecutive days. Muscle biopsies were obtained from the vastus lateralis pre- and post-exercise on days one and three. Muscle samples were analyzed for mRNA content of peroxisome proliferator receptor gamma coactivator-1 alpha (PGC-1alpha), sirtuin 1 (Sirt-1), cytochrome c, and citrate synthase. Data were analyzed using a 2 (time) x 2 (day) repeated measures ANOVA. Of the mRNA analyzed, the following increased from pre to post 3 h rides: cytochrome c (P = 0.006), citrate synthase (P = 0.03), PGC-1alpha (P < 0.001), and Sirt-1 (P = 0.005). The following mRNA showed significant effects from days one to three: cytochrome c (P < 0.001) and citrate synthase (P = 0.01). These data show that exhaustive cycling performed on three consecutive days resulted in both acute and chronic stimuli for mRNA associated with mitochondrial biogenesis in already trained subjects. This is the first study to illustrate an increase in sirtuin-1 mRNA with acute and chronic exercise. These data contribute to the understanding of mRNA expression during both acute and successive bouts of prolonged exercise.
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http://dx.doi.org/10.1007/s00421-009-1143-1DOI Listing
November 2009

Quercetin does not affect rating of perceived exertion in athletes during the Western States endurance run.

Res Sports Med 2009 ;17(2):71-83

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina 28608, USA.

The purpose of this study was to measure the influence of quercetin supplementation on ratings of perceived exertion in ultramarathon runners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin (Q) and placebo (P) groups, and under double blinded methods ingested four supplements per day with or without 250 mg quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (quercetin N = 18, placebo N = 21) finished the race. At the completion of exercise ratings of perceived exertion (RPE) were assessed at aid stations located at 40, 90, 125, 150, and 160 km (finish line). The pattern of change in RPE over time was not significantly different between the Q and P groups. Ratings of perceived exertion (RPE) did not significantly increase throughout the race (15.2 +/- 2.9 at 40 km -14.2 +/- 4.0 at 160 km) for both groups combined. Race times were not different between the groups (Q = 26.4 +/- 0.7 h and P = 27.5 +/- 0.6 h). Significant time main effects (p < 0.001) were found for both serum glucose and cortisol throughout the race. Quercetin supplementation for 3 weeks prior to the WSER had no effect on RPE during competitive self-paced ultramarathon running. Ratings of perceived exertion (RPE) did not increase in a linear fashion but instead fluctuated nonmonotonically throughout the self-paced endurance running event.
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http://dx.doi.org/10.1080/15438620902901474DOI Listing
September 2009

Evaluation of ultrasound in assessing body composition of high school wrestlers.

Med Sci Sports Exerc 2008 May;40(5):943-9

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA.

Purpose: To evaluate the accuracy of ultrasound (ULTRA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state.

Methods: Body composition was determined by ULTRA, HW, and three-site SK in 70 high school wrestlers (mean +/- SD: age, 15.5 +/- 1.5; height, 1.60 +/- 0.08 m; body mass, 65.8 +/- 12.7 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity.

Results: There were no significant differences for estimated FFM between ULTRA (57.2 +/- 9.7 kg) and HW (57.0 +/- 9.9 kg); however, SK (54.9 +/- 8.8 kg) were significantly different from HW. The standard errors of estimate for FFM with HW as the reference method were 2.40 kg for ULTRA and 2.74 kg for SK. Significant correlations were found for FFM between HW and ULTRA (r = 0.97, P < 0.001) and between HW and SK (r = 0.96, P < 0.001). A systematic bias was found for SK, as the difference between SK and HW significantly correlated with the FFM average of the two methods (r = -0.38, P < 0.001). This systematic bias was not found for ULTRA (r = - 0.07).

Conclusions: This study demonstrates that ULTRA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. ULTRA should be considered as an alternative field-based method of estimating the FFM of high school wrestlers.
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http://dx.doi.org/10.1249/MSS.0b013e318163f29eDOI Listing
May 2008

Chronic quercetin ingestion and exercise-induced oxidative damage and inflammation.

Appl Physiol Nutr Metab 2008 Apr;33(2):254-62

Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA.

Quercetin is a flavonoid compound that has been demonstrated to be a potent antioxidant in vitro. The objective of this study was to evaluate if quercetin ingestion would increase plasma antioxidant measures and attenuate increases in exercise-induced oxidative damage. Forty athletes were recruited and randomized to quercetin or placebo. Subjects consumed 1000 mg quercetin or placebo each day for 6 weeks before and during 3 d of cycling at 57% work maximum for 3 h. Blood was collected before and immediately after exercise each day, and analyzed for F2-isoprostanes, nitrite, ferric-reducing ability of plasma, trolox equivalent antioxidant capacity, and C-reactive protein. Statistical analyses involved a 2 (treatment) x 6 (times) repeated measures analysis of variance to test main effects. F2-isoprostanes, nitrite, ferric-reducing ability of plasma, trolox equivalent antioxidant capacity, and C-reactive protein were significantly elevated as a result of exercise, but no group effects were found. Despite previous data demonstrating potent antioxidant actions of quercetin in vitro, this study indicates that this effect is absent in vivo and that chronic quercetin ingestion does not exert protection from exercise-induced oxidative stress and inflammation.
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http://dx.doi.org/10.1139/H07-177DOI Listing
April 2008

Quercetin ingestion does not alter cytokine changes in athletes competing in the Western States Endurance Run.

J Interferon Cytokine Res 2007 Dec;27(12):1003-11

Department of Biology, Health, Leisure, and Exercise Science, Fischer Hamilton/Nycom Biochemistry Laboratory, Appalachian State University, Boone, North Carolina. 28608, USA.

The purpose of this study was to measure the influence of quercetin on plasma cytokines, leukocyte cytokine mRNA, and related variables in ultramarathoners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin and placebo groups and under double-blinded methods ingested 1000 mg/day quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (n = 18 for quercetin, n = 21 for placebo) finished the race and provided blood samples the morning before the race and 15-30 min postrace. Significant prerace to postrace WSER increases were measured for nine proinflammatory and anti-inflammatory plasma cytokines, cortisol (quercetin = 94%, placebo = 96%), serum C-reactive protein (CRP) (mean +/- SE absolute increase, quercetin = 31.8 +/- 4.2, placebo = 38.2 +/- 5.0 mg/L), and creatine kinase (CK) (quercetin = 21,575 +/- 3,977, placebo = 19,455 +/- 3,969 U/L), with no significant group differences. Interleukin-6 (IL-6) mRNA did not change post-WSER, with a significant decrease measured for leukocyte IL-8 mRNA (0.21 +/- 0.03-fold and 0.25 +/- 0.04-fold change from rest, quercetin and placebo, respectively) and significant increases for IL-1Ra mRNA (1.43 +/- 0.18-fold and 1.40 +/- 0.16-fold change, quercetin and placebo, respectively) and IL-10 mRNA (12.9 +/- 3.9-fold and 17.2 +/- 6.1-fold change, quercetin and placebo, respectively), with no significant differences between groups. In conclusion, quercetin ingestion (1 g/day) by ultramarathon athletes for 3 weeks before a competitive 160-km race significantly increased plasma quercetin levels but failed to attenuate muscle damage, inflammation, increases in plasma cytokine and hormone levels, and alterations in leukocyte cytokine mRNA expression.
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http://dx.doi.org/10.1089/jir.2007.0050DOI Listing
December 2007

Effect of duration and exogenous carbohydrate on gross efficiency during cycling.

J Strength Cond Res 2007 Nov;21(4):1214-9

Human Performance Laboratory, Fisher Hamilton/Nycom Laboratory, and Neuromuscular Laboratory, Appalachian State University, Boone, North Carolina 28608, USA.

The purpose of this investigation was to determine the effects of 2.5 hours of cycling with and without carbohydrate supplementation on gross efficiency (GE). Trained cyclists (N = 15) were tested for V(.-)O2max (53.6 + 2.2 ml x kg(-1) x min(-1)) and lactate threshold during incremental tests to exhaustion. On 2 separate visits, cyclists performed 2.5 hours of cycling on an indoor trainer. A carbohydrate (C) or placebo (P) beverage was randomly provided and counterbalanced for each of the trials. Gross efficiency, cycling economy, power output, V(.-)O2, lactate, and blood glucose were measured every 20 minutes during the 2.5-hour ride. Muscle glycogen was measured immediately before and after the ride from the vastus lateralis. Results indicated that power output and V(.-)O2 decreased over time (p < 0.05) but were not different between trials. Relative GE and cycling economy during C were greater than P at 40 and 150 minutes (p < 0.05). Blood glucose significantly decreased in P and was lower than C at all time points (p < 0.05). Respiratory exchange ratio decreased over time in both trials, with a significant treatment effect at 40 and 150 minutes (p < 0.05). Muscle glycogen decreased by 65% during both conditions (p < 0.05) but demonstrated no treatment effect. We conclude that carbohydrate supplementation during 2.5 hours of cycling attenuated the decrease in GE possibly by maintaining blood glucose levels. This suggests that the positive effect of carbohydrate supplementation on endurance performance may be through the maintenance of metabolic efficiency.
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http://dx.doi.org/10.1519/R-22396.1DOI Listing
November 2007
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