bluuebunny/crossref_metadata_2025 huggingface dataset:
Uses and Gratifications of a Retired Female Athlete’s Twitter Followers
Authors: Clavio Galen , Kian Ted M.
Published: August 2016

An Internet-based survey was posted on the Twitter feed of a retired female athlete to ascertain the demographics, uses, and gratifications of her feed’s followers. Analysis of the data revealed that followers were predominantly White, affluent, educated, and older than prior research into online audiences has shown. The perception of the athlete as being an expert at her sport was the most salient reason reported to follow the Twitter feed, followed by affinity for the athlete’s writing style. Analysis of variance uncovered 5 significant differences in item salience between male and female followers, with women more likely to use this Twitter feed because of affinity for the athlete and men more likely to use it because of perception of the athlete as physically attractive. Factor analysis uncovered 3 dimensions of gratification: an organic fandom factor, a functional fandom factor, and an interactivity factor.
Norwegian Big Bang Theory: Production of Gendered Sound During Team Handball Broadcasts
Authors: Broch Trygve B.
Published: August 2016

This study investigates Norwegian television commentary of men’s team handball. Five World Championship games and 5 European Championship games were recorded and all commentaries transcribed. The main focus was to investigate gendered patterns and to suggest ways these patterns might shape particular understandings of the game and its players. By combining Connell’s gender perspectives with discourse analysis, implicit and explicit meanings were located within the commentaries. Further data analysis revealed that televised depictions of men’s handball hold a dominant focus on a specific form of masculinity. Fueled by gendered symbolism and metaphors, the word bang was identified as a key signifier for this particular form of masculinity. The contextual use of bang was analyzed as connoting and reproducing specific notions of sport and masculinities.
“We Aren’t Looking at This as an Audition”: Exploring Interim Leadership in College Athletics
Authors: Browning Blair W. , Kassing Jeffrey W.
Published: August 2016

Interim coaches have become commonplace in college athletics. With much at stake, they must act as leaders despite the constraints that accompany interim status. This case study provides an initial examination of interim leadership in the domain of college athletics by focusing on a specific high-profile interim coach’s initial press conference. The authors specifically consider the content of The Ohio State University football coach Luke Fickell’s first press conference after being named interim head coach. Their analysis reveals that Fickell strategically managed the interim label and the temporal nature of the interim role, balanced service goals and career-aspirant ones, and performed collective identity through a variety of means. The implications of these practices for interim coaches in college athletics are discussed.
On Being a “Good Sport” in the Workplace: Women, the Glass Ceiling, and Negotiated Resignation in Sports Information
Authors: Whiteside Erin , Hardin Marie
Published: August 2016

This research survey explores the gendered work experiences of women in sports information, including their perceptions of the “glass ceiling,” their rationalization strategies for dealing with those perceptions, and the factors contributing to their low numbers in the business. The findings suggest that women perceive a glass ceiling but are hesitant to admit its existence. Second, women are internalizing some of the value systems embedded in this male-dominated industry. Finally, along with perceptions of a glass ceiling, women are facing a “maternal wall” that makes staying in sports information extremely difficult for women with children, given the job’s untraditional schedule.
Relationship Marketing and Social Media in Sport
Authors: Abeza Gashaw , O’Reilly Norm , Reid Ian
Published: August 2016

Relationship marketing (RM) is about retaining customers through the achievement of long-term mutual satisfaction by businesses and their customers. Sport organizations, to retain customers by establishing, maintaining, and enhancing relationships, need to communicate and engage in dialogue with their customers. To achieve this on an ongoing basis, sport organizations need to employ effective communication platforms. In this regard, social media (SM) is becoming an ideal tool for a continuing 2-way dialogue. However, the effects of SM, primarily in terms of addressing RM goals, are not yet well understood. This study explores the opportunities and challenges facing managers in sport organizations in using SM in an RM strategy. Eight case studies were undertaken on organizations that put on running events. The article presents the findings on the use, opportunities, and challenges of SM and recommendations encouraging continued investigation.
Evolution of Sport-Broadcast Commentary: The Case of China
Authors: Watanabe Nicholas M. , Nie Tie , Yan Grace
Published: August 2016

The Olympic Games are one of the most popular global televised sporting events. In the greater body of sport communication literature, a great deal of focus has been placed on examining sport media from the West. This article considers the unique and specific case of Chinese Olympic broadcast commentary televised by state media. In this, an evolutionary process of sport media can be seen in the analysis of several themes: nationalism and identity, heroes and failure, collectivism and individualism, and the portrayal of female athletes. In considering the dynamic changes that have come about in the past 3 decades of Chinese commentary, it is evident that many themes in Chinese sport media have become reflective of those found in Western sport media. While Chinese sport media have similarities to Western sport media, it is important to note that Chinese sport media are unique. Results of this work can help provide richer understanding of sport media and consumers in China.
Effects of Drink Carbonation on the Gastric Emptying Characteristics of Water and Flavored Water
Authors: Zachwieja Jeffrey J. , Costill David L. , Widrick Jeffrey J. , Anderson Dawn E. , McConell Glenn K.
Published: August 2016

The intent of this study was to determine whether adding carbonation to either water or a low calorie sport drink would affect gastric emptying (GE). Fifteen subjects rode for 20 minutes on a cycle ergometer at 55% of max . After 5 minutes of exercise, the subjects ingested 5.5 mllkg body weight of a test solution: water (W), carbonated water (CW), and a low calorie sport drink in both a carbonated (C2C) and noncarbonated (2C) form. At the end of each ride, the stomach was emptied through gastric aspiration. The results indicate that carbonation has no effect on GE. However, the type of drink did have an effect on GE, as both 2C and C2C emptied from the stomach at a slower rate than either W or CW. Subjective ratings of gastrointestinal comfort were similar for both carbonated and noncarbonated forms, and at no time did the subjects report discomfort. The results were independent of the exercise challenge, as exercise intensity, heart rate, and ratings of perceived exertion did not differ between experimental trials. It is concluded that carbonation does not affect the GE characteristics of a drink taken during submaximal exercise, but the flavoring system of the low calorie beverage decreased the rate of GE by as much as 25% when compared to water.
Precontest Strategies of a Male Bodybuilder
Authors: Steen Suzanne Nelson
Published: August 2016

The dietary strategies of a 25-year-old bodybuilder were studied as he prepared for a contest. Food records were kept over a 6-month period that included the off-season, weight reduction phase, and week of a contest. Mean caloric intake during the off-season was 4,193 kcal (49 kcal/kg), Average intake per kg body weight was 8.7 g/kg carbohydrate and 2.8 g/kg protein. During the weight reduction phase of training, mean caloric intake was 3,020 kcal (37 kcal/kg). Carbohydrate intake averaged 6.1 g/kg and protein averaged 2.7 g/kg. The RDA was met for all micronutrients without any need for supplementation. Beginning at 3 weeks before the contest, dietary intake changed dramatically and haddock, rice, or potato were eaten every 2 hours. Protein intake averaged 4 g/kg. Carbo-loading was practiced the week precontest to enhance muscularity. During all phases the subject used anabolic steroids and consumed various supplements. During the off-season he took a high potency multivitamin/multimineral daily and 60-100 grams of amino acids when “needed.” As the competition drew closer, numerous additional supplements were taken. In light of these many unhealthy practices, alternative strategies should be negotiated with the athlete that are realistic, and changes should be implemented slowly.
Eating and Weight Disorders in the Female Athlete
Authors: Wilmore Jack H.
Published: August 2016

This paper presents an overview of eating disorders, including definitions, clinical criteria for appropriate diagnosis, and a discussion of the potential for increased risk for eating disorders in special populations of female athletes. This is followed by a discussion of the prevalence of eating disorders in normal and athletic populations. From this discussion, it seems clear that female athletes in endurance or appearance sports are at an increased risk for disordered eating. Finally, the paper focuses on related disorders—a triad associating eating disorders, menstrual dysfunction, and bone mineral disorders. It is clear that secondary amenorrhea is associated with malnutrition and disordered eating. Further, bone mineral disorders are related to menstrual dysfunction. Disordered eating may represent the initiating factor of this triad.
Gamma Oryzanol–Plant Sterol Supplementation: Metabolic, Endocrine, and Physiologic Effects
Authors: Wheeler Keith B. , Garleb Keith A.
Published: August 2016

The use of gamma-oryzanol and phytosterols is gaining popularity among various athletic populations. These compounds are being consumed in the belief that they elicit anabolic effects ranging from increased testosterone production and release to stimulating human growth hormone release. However, published scientific studies suggest that these compounds are poorly absorbed. Furthermore, animal studies indicate that when these compounds are injected subcutaneously or intravenously, they induce antianabolic or catabolic activity. Normally, less than 5% of orally consumed phytosterols are absorbed from the Intestinal tract, with the majority being excreted in the feces. Intravenous or subcutaneous injections of gamma-oryzanol in rats have been shown to suppress luteinizing hormone release, reduce growth hormone synthesis and release, and increase release of the catecholamines, dopamine and norepinephrine, in the brain. Although it hasn't been directly measured, this metabolic milieu, if accurate, may actually reduce testosterone production.
Muscle Damage: Nutritional Considerations
Authors: Evans William J.
Published: August 2016

Most exercise results in some skeletal muscle damage. However, unaccustomed exercise andlor eccentric exercise can cause extensive damage. This exercise-induced muscle damage causes a response that can be characterized by a cascade of metabolic events. Within 24 to 48 hours, delayed onset muscle soreness and weakness, the most obvious manifestations of the damage, peak. Increased circulating neutrophils and interleukin-1 occurs within 24 hours after the exercise, with skeletal muscle levels remaining elevated for a much longer time. There is a prolonged increase in ultrastructural damage and muscle protein degradation as well as a depletion of muscle glycogen stores. These metabolic alterations may result in the increased need for dietary protein, particularly at the beginning of a training program that has a high eccentric component such as strength training. The delay in muscle repair and glycogen repletion following damaging exercise should cause coaches and athletes to allow an adequate period of time between competition for complete recovery.
Consumption of Carbonated and Noncarbonated Sports Drinks during Prolonged Treadmill Exercise in the Heat
Authors: Ryan Alan J. , Navarre Amy E. , Gisolfi Carl V.
Published: August 2016

These studies were done to determine the effect of carbonation and carbohydrate content on either gastric emptying or ad libitum drinking during treadmill exercise in the heat. Four test drinks were used: a 6% carbohydrate, noncarbonated; a 6% carbohydrate, carbonated; a 10% carbohydrate, noncarbonated; and a 10% carbohydrate, carbonated drink. For gastric emptying studies, subjects completed four 1-hr treadmill runs in the heat. They were given 400 mL of test drink at 0 rnin and 200 mL at 15, 30, and 45 min of exercise. For ad libitum drinking studies, subjects completed four 2-hr treadmill runs in the heat. Gastric residual volumes were similar during the four 1-hr runs. During the 2-hr runs, ad libitum drinking of the four beverages was also similar. Mean values for sweat rate, percentage of body weight lost, and percentage of fluid replaced by ad libitum drinking were similar for the four trials. Similar changes in heart rate, rectal temperature, and ratings of perceived exertion were also observed during the four 2-hr treadmill runs. We conclude that the presence of carbonation in a carbohydrate drink did not have a significant effect on either gastric emptying or ad libitum drinking.
Nutritional Concerns of Female Athletes: A Case Study
Authors: Clark Nancy
Published: August 2016

Some of the nutritional concerns of female athletes are highlighted in this case study of a 20-year-old woman who wants to lose 16% of her body weight to qualify for the position of coxswain on a national crew team. These concerns include adequacy of vitamin, mineral, protein, and carbohydrate intake as well as amenorrhea and pathogenic eating behaviors.
A Comparison between Running and Weight Lifting on Fasting Plasma Lipids of a Well-Conditioned Hypercholesterolemic Male
Authors: Warber John , Bazzarre Terry
Published: August 2016

The effect of weight lifting and running on the plasma lipid profiles of a physically fit 32-year-old hypercholesterolemic male were determined while he adhered to a controlled Phase III American Heart Association diet. The subject followed the same daily menu pattern for the entire test period. He completed four treatment phases: 6 weeks of detraining, 10 weeks of weight lifting, 10 weeks of running, and 10 weeks of weight lifting. The study was designed to closely compare two modes of exercise training for the same duration. A complete lipid profile was analyzed at baseline and every 5 weeks thereafter. Body weight and body fat remained constant throughout the study. Results revealed that running was the only effective treatment in raising high-density lipoprotein cholesterol (HDL-C). A return to weight lifting was associated with a 4 mg % decrease in HDLC. The controlled low-fat, high carbohydrate, and low cholesterol diet effectively reduced total cholesterol, low-density, and high-density lipoprotein cholesterol in this hypercholesterolemic subject, while running increased HDL-C.
Plasma Glucose Kinetics in a Well-Trained Cyclist Fed Glucose Throughout Exercise
Authors: Coggan Andrew R. , Spina Robert J. , Kohrt Wendy M. , Bier Dennis M. , Holloszy John O.
Published: August 2016

We hypothesized that when plasma glucose availability is maintained by carbohydrate (CHO) ingestion, trained cyclists can utilize plasma glucose at very high rates during the later stages of prolonged exercise (10). To test this hypothesis, a well-trained male cyclist was studied during exercise to fatigue at 70% when ingesting glucose throughout exercise. A primed continuous infusion of [U-13C]glucose was begun after 60 min of exercise to measure rates of plasma glucose appearance (), disappearance (), and oxidation (). and rose progressively throughout exercise, peaking at 6.85 and 6.99 mmollmin, respectively, at fatigue (i.e., 133 min). Most (93%) of this glucose was oxidized; during the final 30 min of exercise, , averaged 6.10 mmollmin and accounted for approximately half of total CHO oxidation. These results support the hypothesis that trained cyclists can oxidize plasma glucose at very high rates during the later stages of prolonged exercise when fed CHO.
Failure of Low Dose Carbohydrate Feeding to Attenuate Glucoregulatory Hormone Responses and Improve Endurance Performance
Authors: Burgess William A. , Davis J. Mark , Bartoli William P. , Woods Jeffrey A.
Published: August 2016

The effects of ingesting a low dose of CHO on plasma glucose, glucoregulatory hormone responses, and performance during prolonged cycling were investigated. Nine male subjects cycled for 165 min at ≈67% peak followed by a two-stage performance ride to exhaustion on two occasions in the laboratory. Every 20 min during exercise, subjects consumed either a flavored water placebo (P) or a dilute carbohydrate beverage (C). Blood samples were collected immediately before, every 20 min throughout, and immediately after exercise. Plasma was analyzed for glucose, lactate, free fatty acids (FFA), and various glucoregulatory hormones. , RER, heart rate, perceived exertion, and exercise performance were also measured. Lactate, FFA, epinephrine, norepinephrine, ACTH, cortisol, and glucagon increased with exercise whereas glucose and insulin decreased (p≤05). Except for a small difference in glucose at 158 min of exercise and at exhaustion, no significant differences were found between drinks for any of the variabfes studied (p ≥ 05). Ingestion of 13 g carbohydrate per hour is not sufficient to maintain plasma glucose, attenuate the glucoregulatory hormone response, and improve performance during prolonged moderate intensity cycling.
Anaerobic Power Responses to Amino Acid Nutritional Supplementation
Authors: Maresh Carl M. , Gabaree Catherine L. , Hoffman Jay R. , Hannon Daniel R. , Deschenes Michael R. , Armstrong Lawrence E. , Abraham Avron , Bailey Frederick E. , Kraemer William J.
Published: August 2016

To examine the effect of a nutritional supplement (ATP-E™) on high intensity exercise performance, 23 physically active males volunteered to perform six Wingate Anaerobic Power tests. Tests were performed prior to and at 14 and 21 days during ATP-E~o~r placebo ingestion. f i e experiment followed a double-blind and random-order design. Twelve subjects (responders, R) showed an increase in preexercise blood ATP on Day 14 of ATP-E™ ingestion compared to control measures. The remaining 11 subjects (nonresponders, NR) had no change in pree~e~cibselo od ATP. Peak power and mean power were unchanged for both R and NR subjects across the exercise tests, but R experienced a decrease (p < 0.05) in immediate postexercise plasma lactate on Day 14 of ATP-E™ testing compared to their control measures. NR had no change in peak plasma lactate at any time during the study. The results suggest that short-term high intensity exercise performance was maintained in R with less reliance on anaerobic metabolism, and that response was evident following 14 days of ATP-E™ ingestion.
Exercise Intensity and the Thermic EfiWif of Food
Authors: Goben Kent W. , Sforzo Gary A. , Frye Patricia A.
Published: August 2016

This study investigated the effect of varying exercise intensity on the thermic effect of food (TEF). Sixteen lean male subjects were matched for and randomly assigned to either a high or low intensity group for 30 min of treadmill exercise. Caloric expenditure was measured using indirect calorimetry at rest and at 30-min intervals OYer 3 hrs following each of three conditions: a 750-kcal liquid meal, high or low intensity exercise, and a 750-kcal liquid meal followed by high or low intensity exercise. Low intensity exercise enhanced the TEF during recovery at 60 and 90 min while high intensity enhanced it only at 180 min but depressed it at 30 min. Total metabolic expense for a 3-hr postmeal period was not differently affected by the two exercise intensities. Exercise following a meal had a synergistic effect on metabolism; however, this effect was delayed until 180 min postmeal when exercise intensity was high. The circulatory demands of high intensity exercise may have initially blunted the TEF, but ultimately the TEF measured over the 3-hr period was at least equal to that experienced following low intensity exercise.
The Effect of 7 to 8 months of Vitamin/Mineral Supplementation on the Vitamin and Mineral Status of Athletes
Authors: Telford Richard D. , Catchpole Edward A. , Deakin Vicki , McLeay Alan C. , Plank Ashley W.
Published: August 2016

Blood indicators of eight vitamins (, , , C, E, A, B,12 folate) and six minerals (Cu, Mg, Zn, Ca, P, Al) were measured in 86 athletes before and after a 7- to 8-month period of training. During this period half consumed a multivitamin/mineral supplement and a matched group look a placebo, Following the supplementation period, Mood biochemical indicators of , , , and folate status all increased but there were no significant effects of supplementation on , C, E, and A, or on the blood levels of any of the minerals. The supplementation had no effect on red or while cell counts or on hemoglobin levels. Irrespective of the supplementation, some blood measures varied according to sex, females evidencing significantly higher values than males for vitamins C, E, copper, magnesium, and aluminum, with being higher in males. It is concluded that 7 to 8 months of multivitamin/mineral supplementation increased the blood nutritional status of some vitamins but did not affect any blood mineral levels, and that some blood nutritional indicators may vary according to sex.
Failure of Magnesium Supplementation to Influence Marathon Running Performance or Recovery in Magnesium-Replete Subjects
Authors: Terblanche Sonja , Noakes Timothy D. , Dennis Steven C. , Marais De Wet , Eckert Michael
Published: August 2016

This study examined the effect of magnesium supplementation on muscle magnesium content, on running performance during a 42-kni marathon footrace, and on muscle damage and the rate of recovery of muscle function following the race. Twenty athletes were divided equally into two matched groups and were studied for 4 weeks before and 6 weeks after a marathon in a double-blind trial; the experimental group received magnesium supplement (365 mg per day) and the control group, placebo. Magnesium supplementation did not increase either muscle or serum magnesium concentrations and had no measurable effect on 42-km marathon running performance. Extra magnesium ingestion also had no influence on the extent of muscle damage or the rate of recovery of muscle function. The latter was significantly reduced immediately after the marathon but returned to normal within 1 week. Thus, magnesium supplementation in magnesium-replete subjects did not enhance performance or increase resistance to muscle damage during the race, or the rate of recovery of muscle function following the race.
Does Calcium Supplementation Prevent Bone Stress Injuries? A Clinical Trial
Authors: Schwellnus Martin P. , Jordaan Gerhard
Published: August 2016

This study investigated the effect of calcium supplementation in preventing bone stress injuries. Healthy male military recruits (N=1,398) served as subjects, of which 247 were randomly allocated to an experimental group (E) while 1,151 served as a control group (C). For 9 weeks both groups wore the same footwear and had the same physical training program. The baseline dietary intake of calcium in 50 randomly selected subjects of each group was assessed using a 24-hr dietary record. The E group received a daily calcium supplement while the C group did not. Injuries were monitored in all subjects by a panel of doctors who followed specific diagnostic criteria. The mean weekly injury incidence for all overuse injuries, but specifically tibial stress syndrome and stress fractures, was similar in both groups. Mean baseline daily dietary calcium intake was above 800 mg in both subgroups. This study demonstrated that large-scale calcium supplementation (500 nig/ day) beyond usual dietary intake did not influence the risk of developing bone stress injuries during a 9-wk physical training program in these young military recruits.
Rationale for Upper Limits of Electrolyte Replacement during Exercise
Authors: Brouns Fred , Saris Wim , Schneider Heinz
Published: August 2016

The addition of carbohydrate and sodium to sport drinks has been recommended to enhance fluid intake and absorption and to delay fatigue. Other electrolytes (E) which are lost through sweating are also commonly added. However, too many E may lead to increased serum E and osmolality levels, which may negatively influence thermoregulation, depress sweating, and cause gastrointestinal distress. On the other hand, drinking large amounts of plain water to compensate sweat loss may induce hyponatremia. Therefore, literature describing sweat E losses was examined in order to estimate average whole-body E loss and to determine an upper limit for replacement of E with sport drinks. Mean E loss was determined from 13 studies, with +1 SD resulting in a hypothetical range for E losses. Correction for net absorption resulted in an upper limit of electrolyte replacement. It is suggested that the E levels in sport rehydration drinks should not exceed the upper limit of the range given.
The Effects of a Carbonated Carbohydrate Drink on Gastric Emptying, Gastrointestinal Distress, and Exercise Performance
Authors: Zachwieja Jeffrey J. , Costill David L. , Beard Glenn C. , Robergs Robert A. , Pascoe David D. , Anderson Dawn E.
Published: August 2016

To determine the effect of a carbonated carbohydrate (CHO) drink on gastric function and exercise performance, eight male cyclists completed four 120- min bouts of cycling. Each bout consisted of a 105-min ride at 70% followed by a 15-min self-paced performance ride. During each trial, one of four test solutions was ingested: carbonated CHO (C-10%), noncarbonated CHO (NC-10%), carbonated non-CHO (C), and noncarbonated non-CHO (NC). Following the performance ride, the subjects had their stomach contents removed by aspiration. There were no significant differences in gastric emptying (GE) except for Trial C-10%, which averaged 13.3% less than NC. However, there was no difference in the perception of gastrointestinal comfort between this trial and any other. Average power output during the performance ride was not significantly different between carbonated and noncarbonated trials, or between CHO-fed and no-CHO trials; however, the subjects worked at a greater intensity when fed CHO. Finally, acid base status did not change when a carbonated drink was ingested. This indicates that adding carbonation to a sport drink does not significantly alter gastric function, the perception of GI comfort, or exercise performance.
Effects of Downhill Running on the Responses to an Oral Glucose Challenge
Authors: Sherman William M. , Lash Julie M. , Simonsen John C. , Bloomfield Susan A.
Published: August 2016

Because muscle damage from eccentric exercise has been associated with alterations in muscle glycogen metabolism, this study determined the effects of exercise on the insulin and glucose responses to an oral glucose tolerance test (OGTT). In a repeated-measures design, 11 subjects undertook either no exercise, 2 min of isokinetic leg exercise, or 50 min of level or downhill running. No exercise was performed and diet was controlled during the 48 hrs after the treatments and before the OGTT. Ratings of muscle soreness and CK activity were significantly elevated 48 hrs after downhill running. Level running also increased CK activity but did not induce muscle soreness. Isokinetic exercise did not affect either one. Blood glucose responses to the OGTT were similar among the treatments. In contrast, the insulin responses to the OGTT following downhill running were significantly increased. These results suggest that eccentric exercise associated with downhill running that results in delayed muscle soreness is associated with the development of a mild insulin-resistant condition.
Ornithine Supplementation and Insulin Release in Bodybuilders
Authors: Bucci Luke R. , Hickson James F. , Wolinsky Ira , Pivarnik James M.
Published: August 2016

Ornithine supplementation has gained popularity with athletes because of its alleged potential to release anabolic hormones, factors governing skeletal muscle hypertrophy. Three female and nine male bodybuilders sewed as subjects in a study to test the effectiveness of oral ornithine in bringing about the release of insulin, an anabolic hormone. After an overnight fast, subjects were administered 40, 100, or 170 mg·kg−1 L-ornithine.HC1 by mouth in a random fashion on three consecutive Saturday mornings. Blood samples were drawn at baseline (T=O), 45, and 90 min afterward. Serum ornithine levels were elevated (p~0.01) at T=45 and 90 min for all three dosage levels. However, serum insulin did not change from baseline levels at any dose of ornithine. The present findings show that ornithine is not an insulin secretagogue.
The Effect of Protein Supplementation on Lactate Accumulation during Submaximal and Maximal Exercise
Authors: Vukovich Matthew D. , Sharp Rick L. , King Douglas S. , Kershishnik Kellie
Published: August 2016

Eleven subjects performed a graded exercise test after 1 week of protein supplementation (PRO) or glucose polymer placebo (CON), randomly assigned in a double blind fashion. The exercise consisted of 3-min graded exercise bouts separated by 10 min of active recovery at zero pedal resistance. Subjects then performed a 30-sec Wingate test (WIN) to assess performance during supramaximal exercise. Blood samples were obtained in the last 15 sec of each exercise and recovery period. PRO resulted in a decrease in blood lactate following 120% and WIN, an increase in blood alanine at all time points, and lower postexercise muscle lactate and glycogen. Resting muscle GPT activity was 47% higher during the PRO trial. Mean power output during the WIN did not differ between PRO and CON. The WIN fatigue index was not significantly different between PRO and CON. The increased alanine may reflect increased transamination of pyruvate, thereby reducing the accumulation of lactate, which in turn had a marginal effect on performance during supramaximal exercise.
Plasma Ferritin Concentration and Physical Work Capacity in Athletes
Authors: Telford Richard D. , Bunney Christopher J. , Catchpole Edward A. , Catchpole Wendy R. , Deakin Vicki , Gray Bon , Hahn Allan G. , Kerr Deborah A.
Published: August 2016

This investigation aimed to determine whether the physical work capacity of nonanemic athletes could be improved when plasma ferritin concentrations of below 30 nglml were raised at least 15 ng/ml. The experimental group consisted of 15 training athletes, each of whose plasma ferritin concentration was less than 30 ng/ml (mean and SD of 19.8 ±8.4 nglml). In a control group of 16, each was measured with a plasma ferritin concentration of more than 40 ng/ml (mean and SD of 83.3 ±37.6 ngfml). All participated in submaximal and maximal tests for aerobic and anaerobic power. Following iron supplementation, plasma fenitin concentration in each experimental subject increased by at least 15 nglml to more than 30 ng/ml, to a new mean of 46.3 ±15.5 ng/ml. The performance measures were also repeated, but no significant overall effects were associated with the increased plasma ferritin concentrations. These data provide no sound evidence that physical work capacity of athletes is enhanced when plasma ferritin concentrations of around 20 ng/ml are increased by at least 15 ng/ml.
Effects of Low Ferritin Concentration on Endurance Performance
Authors: Lamanca John J. , Haymes Emily M.
Published: August 2016

To determine the effects of depleted iron stores on endurance performance and blood lactate concentration, eight active women with normal (>26 ng/ml) and eight with low (< I2 nglml) plasma ferritin concentrations were studied while performing a and an endurance test (80% ) on a cycle ergometer. The low femtin group had significantly lower serum iron concentration and transferrin saturation and higher TIBC than the normal femtin group. Mean was not significantly different between groups. No significant difference was found in total time to exhaustion during the endurance test for low (23.2 min) and normal (27.0 min) femtin groups; however, the normal femtin group exercised 14% longer. Blood lactate concentrations following the VOzmax and endurance test did not differ significantly between groups. Food diaries revealed lower daily absorbable iron intake by the low femtin group compared to the normal ferritin group. Ferritin concentration was significantly related to absorbable iron (r=.72) and total iron (r=.70) intake. The results suggest that women with depleted iron stores who are not anemic may have less endurance, but do not have higher blood lactate during exercise than women with normal iron stores.
Effects of Caffeine Ingestion on Metabolic Responses to Prolonged Walking in Sedentary Males
Authors: Engels Herman-J. , Haymes Emily M.
Published: August 2016

This study examined the effects of a single dose of caffeine (5 mg:kg−1) on energy metabolism during 60-min treadmill walking at light (30% ) and moderate (50% ) aerobic intensities in eight sedentary ( 39.6 ±t3.1 ml.kg−1.min−1) males. Caffeine intake 60 min prior to walking exercise increased pre- and postexercise FFA, glycerol, and lactate concentrations (p < 0.05). Blood glucose levels following walking trials were lower than preexercise values (p < 0.05). Gas exchange indicated that caffeine did not change exercise oxygen uptake, RER values, and carbon dioxide production (p0.05). In contrast, a small but statistically significant effect of caffeine on exercise minute ventilation was noted (p~0.01). It is concluded that ingestion of 5 mg.kg−1 caffeine increases the mobilization of energy substrate from fat sources; however, the present data do not provide evidence of a caffeineinduced shift in energy substrate usage. Caffeine is not an effective means for enhancing the energy cost of prolonged walking.
Effects of Sodium Bicarbonate Ingestion on Anaerobic Performance: A Meta-Analytic Review
Authors: Matson Larry G. , Tran Zung Vu
Published: August 2016

Many researchers have investigated the effects of induced metabolic alkalosis, by ingestion of sodium bicarbonate, on anaerobic exercise performance. But the results have been inconsistent and often contradictory. The purpose of this review was to synthesize the varied findings using a meta-analytic approach. Twenty-nine investigations met our inclusion criteria. Results show that , ingestion clearly results in a more alkaline extracellular environment. The dosage, however, was only moderately related to the increase in pH and HCO3-. Overall, performance was enhanced but the range of effect sizes was large, -0.12 to 2.87. In studies that measured time to exhaustion, there was a mean 27±20% increase in duration. The treatment effect, however, was only weakly related to the degree of induced alkalosis. But in comparing the 19 studies that showed a positive treatment effect with the 16 that showed no effect, the former were associated with a greater increase in pH following ingestion of a somewhat larger dosage, and a greater decrease in pH with exercise.
Differences in the Effects of Carbohydrate Food Form on Endurance Performance to Exhaustion
Authors: Murdoch Scott D. , Bazzarre Terry L. , Snider Ian P. , Goldfarb Allan H.
Published: August 2016

This investigation examined the metabolic and performance effects of ingesting solid compared to slurried carbohydrate food (bananas) between two prolonged exhaustive exercise bouts. Eight highly trained bale triathletes performed four exhaustive endurance tests (ET), each separated by at least 2 weeks. Each ET consisted of a 90-min run followed by 90 min of cycling, both at 70% . Workloads were then gradually increased on the cycle, and subjects continued to cycle until exhausted. They then rested for 20 min and ingested one of the following: an artificially sweetened placebo drink (P), slurried bananas (SL), or solid bananas (SO). Bananas were given in equal portions relative to each subject's body weight. Subjects cycled to exhaustion a second time at 70% of their , at which point the mean blood glucose concentration for the combined carbohydrate treatments was significantly higher than that from the P treatment. The mean glucose concentration from the SL treatment did not differ significantly from the SO treatment. These data demonstrate that solid bananas are as effective as slurried bananas in maintaining plasma glucose and in enhancing endurance exercise performance.
The Effects of Intermittent Liquid Meal Feeding on Selected Hormones and Substrates during Intense Weight Training
Authors: Fahey Thomas D. , Hoffman Karen , Colvin William , Lauten Gregory
Published: August 2016

This study examined the effects of feeding a liquid meal during weight training on selected hormones and substrates. Ten male subjects were given a meal (MW) or nonnutritive placebo (W) before and intermittently during a 2-hr weight training session, and a meal before and intermittently during 2 hours of rest (M). Serum insulin increased from 12.2 ± 1.2 and 11.2 ± 1.3 before feeding to 37.2 ± 4.8 and 45.0 ± 5.0 mU · during exercise in MW and M, respectively, and remained elevated for 120 min. Insulin remained at resting levels in W throughout the experiment. Glucose increased from 5.20 ± 0.16 and 4.82 ± 0.20 before feeding to 6.23 ± 0.30 and 6.0 ±0.36 mmol 1−1 at the beginning of exercise in MW and M. Glucose declined during the first 15 min of exercise in MW and M but remained at or above resting levels for 120 min in MW. Lactate increased above 5.9 mmol · in W and MW during exercise. Glucagon remained unchanged in all groups. Perceived exertion during exercise was 8.5±0.16 for MW and 8.3±0.18 for W. Feeding a liquid meal before and during weight training exercise can increase serum insulin and maintain blood glucose for a prolonged period.
Diet and Exercise Strategies of a World-Class Bodybuilder
Authors: Manore Melinda M. , Thompson Janice , Russo Marcy
Published: August 2016

This study presents the diet and exercise strategies of a world-class bodybuilder during an 8-week precompetition period. Weighed food records were kept daily, and body fat, resting metabolic rate (RMR), , blood lipids, and liver enzymes were measured. Two hrs of aerobic exercise and 3 hrs of weight training were done daily 6 daystweek. Mean energy intake was 4,952 kcallday (54 kcallkg) and included 1,278 kcallday from mediumchain triglycerides (MCT). Diet without MCT provided 76% of energy from carbohydrate, 19% from protein (1.9 g proteiag), and 5% from fat. Micronutrients were consumed at ≥ 100% of the RDA, except for zinc and calcium, without supplementation. Mean RMR was 2,098 kcallday and represented 43% of energy intake. was 53 ml.kg−1.min−1. Underwater weighing showed that body fat decreased from 9% to 7%. Blood lipids were normal, but two liver enzymes were elevated (alanine and aspartate aminotransferase). This world-class bodybuilder achieved body fat goals by following a nutrient dense, high energy, high carbohydrate diet and an exercise program that emphasized both aerobic and anaerobic metabolism.
The Effect of Boron Supplementation on Lean Body Mass, Plasma Testosterone Levels, and Strength in Male Bodybuilders
Authors: Ferrando Arny A. , Green Nancy R.
Published: August 2016

The effect of boron supplementation was investigated in 19 male bodybuilders, ages 20–27 years. Ten were given a 2.5-mg boron supplement while 9 were given a placebo every day for 7 weeks. Plasma total and free testosterone, plasma boron, lean body mass, and strength measurements were determined on Days 1 and 49 of the study. Plasma boron values were significantly (p<0.05) different as the experimental group increased from (±SD) 20.1 ±7.7 ppb pretest to 32.6 ±27.6 ppb posttest, while the control group mean decreased from 15.1 ±14.4 ppb pretest to 6.3 ±5.5 ppb posttest. Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders, and that boron supplementation had no effect on these measures.
Lack of Association between Indices of Vitamin B1, B2, and B6, Status and Exercise-Induced Blood Lactate in Young Adults
Authors: Fogelholm Mikael , Ruokonen Inkeri , Laakso Juha T. , Vuorimaa Timo , Himberg Jaakko-Juhani
Published: August 2016

By means of a 5-week vitamin B-complex .supplementation, associations between indices of vitamin B1, B2, and B6, status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18–32 yrs), were randomized into vitamin (n=22) and placebo (n=20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p<0.0001) after supplementation: transketolase decreased from l. 16 (1.14–1.18) (mean and 95% confidence interval) to 1.08 (1.06–1.10); glutathione reductase decreased from 1.33 (1.28–1.39) to 1 .I4 (1.1 1–1.17); and aspartate aminotransferase decreased from 2.04 (1.94–2.14) to 1.73 (1.67–1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.
Responses to Moderate and Low Sodium Diets during Exercise-Heat Acclimation
Authors: Armstrong Lawrence E. , Hubbard Roger W. , Askew E. Wayne , De Luca Jane P. , O'Brien Catherine , Pasqualicchio Angela , Francesconi Ralph P.
Published: August 2016

This investigation examined whether low sodium (Na+) (LNA; 68 mEq Na+·d-1) or moderate Na+ (MNA; 137 mEq Na+.d-1) intake allowed humans to maintain health, exercise, and physiologic function during 10 days of prolonged exercise-heat acclimation (HA). Seventeen volunteers, ages 19 to 21, consumed either LNA (n=8) or MNA (n=9) during HA (41°C, 21% RH; treadmill walking for 30 min.h-1, 8 h·d-1 at 5.6 kmh-l, 5% grade), which resulted in significantly reduced heart rate, rectal temperature, and urine Na+ for both groups. There were few between-diet differences in any variables measured. Mean plasma volume in LNA expanded significantly less than in MNA by Days 11 and 15, but reached the MNA level on Day 17 (+12.3 vs. +12.4%). The absence of heat illness, the presence of normal physiologic responses, and the total distance walked indicated successful and similar HA with both levels of dietary Na+.
Failure of Commercial Oral Amino Acid Supplements to Increase Serum Growth Hormone Concentrations in Male Body-Builders
Authors: Lambert Michael I. , Hefer Janet A. , Millar Robert P. , Macfarlane Peter W.
Published: August 2016

Amino acids are commonly ingested as ergogenic aids in the belief that they enhance protein synthesis and stimulate growth hormone release. The aim of this study was to determine the acute effect that amino acid supplements have on serum growth hormone (GH) concentration. Seven male bodybuilders reported to the laboratory on four occasions after an 8-hr fast and ingested, in random order, either a placebo, a 2.4-g arginine/lysine supplement, a 1.85-g ornithine/tyrosine supplement, or a 20-g BovrilR drink. Blood was collected before each treatment and again every 30 minutes for 3 hours for the measurement of serum GH concentration. On a separate occasion, subjects had an intravenous infusion of 0.5 fig GH-releasing hormone-kg ' body weight to confirm that GH secretory response was normal. The main finding was that serum GH concentrations were not altered consistently in healthy young males following the ingestion of the amino acid supplements in the quantities recommended by the manufacturers.
Exercise, Oxidative Stress, and Antioxidants: A Review
Authors: Jenkins Robert R.
Published: August 2016

Elemental and gaseous oxygen presents a conundrum in that it is simultaneously essential for and potentially destructive to human life. Traditionally the ability to consume large volumes of oxygen has been assumed to be totally beneficial to the organism. In the past 10 years it has become clear that oxygen radicals are generated even during normal resting metabolism Nevertheless, such radicals are usually of no appreciable threat since a wide array of protective biochemical systems exist. However, under certain circumstances aerobic exercise may increase free radical production to a level that overwhelms those defenses. A broad array of nutrients such as vitamin C, vitamin E, p-carotene, and so forth are known to suppress such radical events. This paper reviews the status of our knowledge relative to the potential benefits of nutritional modification in augmenting the organism's normal defense against harmful radical chemistry.
Effects of Varying Levels of Hypohydration on Ratings of Perceived Exertion
Authors: Dengel Donald R. , Weyand Peter G. , Black Donna M. , Cureton Kirk J.
Published: August 2016

To investigate the effects of varying levels of hypohydration on ratings of perceived exertion (RPE) during moderate and heavy submaximal exercise, and at the lactate threshold (LT) and ventilatory threshold (VT), 9 male subjects cycled under states of euhydration (EU), moderate hypohydration (MH), and severe hypohydration (SH). The desired level of hypohydration was achieved over a 36-hr period by having subjects cycle at 50% VO2max in a 38°C environment on two occasions while controlling fluid intake and diet. During submaximal exercise, oxygen uptake, ventilation, heart rate, blood lactate, and RPE were not significantly different among treatments. Hypohydration did not significantly alter LT or VT, or perceptual responses at LT or VT. It is concluded that hypohydration of up to 5.6% caused by fluid manipulation and exercise in the heat over a 36-hr period does not alter RPE or the lactate or ventilatory threshold, nor RPE at the lactate and ventilatory thresholds measured during moderate and heavy submaximal cycling in a neutral (22°C) environment.
Metabolic Responses When Different Forms of Carbohydrate Energy Are Consumed during Cycling
Authors: Lugo Manuel , Sherman William M. , Wimer Gregory S. , Garleb Keith
Published: August 2016

This study examined the effects of consuming the same amount of carbohydrate in solid form, liquid form, or both on metabolic responses during 2 hrs of cycling at 70% peak VO2 and on cycling time-trial performance. Subjects consumed 0.4 g carbohydrate/kg body mass before and every 30 min during exercise. The liquid was a 7% carbohydrate-electrolyte beverage and the solid was a sports bar (1171 kJ) in which 76%, 18%, and 6% of total energy was derived from carbohydrate, fat, and protein, respectively. Blood obtained at baseline, before exercise, and every 30 min was analyzed for glucose, insulin, lactate, hemoglobin, hematocrit, and plasma volume. There were no differences among the treatments for the blood parameters. Total carbohydrate oxidation and time-trial performance were also similar among treatments. Under thermoneutral conditions with equal liquid inges-tion, the metabolic and performance responses are similar when consuming carbohydrate as a liquid, solid, or in combination during prolonged, moderate intensity cycling.