bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Deer Antler Velvet Extract or Powder Supplementation on Aerobic Power, Erythropoiesis, and Muscular Strength and Endurance Characteristics
Authors: Sleivert Gordon , Burke Val , Palmer Craig , Walmsley Alan , Gerrard David , Haines Stephen , Littlejohn Roger
Published: August 2016

To determine the effects of deer antler velvet on maximal aerobic performance and the trainability of muscular strength and endurance, 38 active males were randomly assigned in a double-blind fashion to either deer antler velvet extract (n = 12), powder (n = 13), or placebo groups (n = 13). Subjects were tested prior to beginning supplementation and a 10-week strength program, and immediately post-training. All subjects were measured for circulating levels of testosterone, insulin-like growth factor, erythropoietin, red cell mass, plasma volume, and total blood volume. Additionally, muscular strength, endurance, and VO2max were determined. All groups improved 6 RM strength equivalently (41 ± 26%, p < .001), but there was a greater increase in isokinetic knee extensor strength (30 ± 21% vs. 13 ± 15%, p = .04) and endurance (21 ± 19% vs. 7 ± 12%, p = .02) in the powder compared to placebo group. There were no endocrine, red cell mass or VO2max changes in any group. These findings do not support an erythropoetic or aerobic ergogenic effect of deer antler velvet. Further, the inconsistent findings regarding the effects of deer antler velvet powder supplementation on the development of strength suggests that further work is required to test the robustness of the observation that this supplement enhances the strength training response and to ensure this observation is not a type I error.
Use of Dietary Supplements by Elite Figure Skaters
Authors: Ziegler Paula J. , Nelson Judy A. , Jonnalagadda Satya S.
Published: August 2016

The present study examined the prevalence of dietary supplement use among elite figure skaters, gender differences in supplement use, and differences in nutrient intake of supplement users versus non-users. Male (n = 46) and female (n = 59) figure skaters completed a supplement survey and 3-day food records. Descriptive analysis, chi-square test, and independent t tests were used to analyze the data. Sixty-five percent of male (n = 30) and 76% of female (n = 45) figure skaters reported use of supplements. Forty-seven percent of males and 55% of females reported daily use of supplements. Multivitamin-mineral supplements were the most popular dietary supplements consumed by figure skaters. Significant gender differences were observed in the use of multivitamin-mineral supplements (61% males vs. 83% females, p < .05). Echinacea and ginseng were popular herbal supplements used by these skaters. The 3 main reasons given by male figure skaters for taking supplements were: to provide more energy (41%), to prevent illness or disease (34%), and to enhance performance (21%). Among female figure skaters, the 3 main reasons given were: to prevent illness or disease (61%), to provide more energy (39%), and to make up for an inadequate diet (28%). Significant differences (p < .05) were observed in protein, total fat, saturated fat, polyunsaturated fat intakes, and % energy from carbohydrate and total fat of male supplement users versus non-users, with supplement users having higher intakes except for percent energy from carbohydrate. Sodium was the only nutrient significantly different (p < .05) among female supplement users versus non-users, with supplement users having lower intakes. Given the popularity of dietary supplements, it is important to understand the factors influencing athletes’ use of supplements, their knowledge and attitudes regarding supplements, dosage of supplements used, and the effectiveness of these dietary supplements in meeting the goals of the athletes.
Effect of α-Lipoic Acid Combined with Creatine Monohydrate on Human Skeletal Muscle Creatine and Phosphagen Concentration
Authors: Burke Darren G. , Chilibeck Philip D. , Parise Gianni , Tarnopolsky Mark A. , Candow Darren G.
Published: August 2016

α-lipoic acid has been found to enhance glucose uptake into skeletal muscle in animal models. Studies have also found that the co-ingestion of carbohydrate along with creatine increases muscle creatine uptake by a process related to insulin-stimulated glucose disposal. The purpose of this study was to determine the effect of α-lipoic acid on human skeletal muscle creatine uptake by directly measuring intramuscular concentrations of creatine, phosphocreatine, and ad-enosine triphosphate when creatine monohydrate was co-ingested with α-lipoic acid. Muscle biopsies were acquired from the vastus lateralis m. of 16 male subjects (18–32 y) before and after the experimental intervention. After the initial biopsy, subjects ingested 20 g · d−1 of creatine monohydrate, 20 g · d−1 of creatine monohydrate + 100 g · d−1 of sucrose, or 20 g · d−1 of creatine monohydrate + 100 g · d−1 of sucrose + 1000 mg · d−1 of α-lipoic acid for 5 days. Subjects refrained from exercise and consumed the same balanced diet for 7 days. Body weight increased by 2.1% following the nutritional intervention, with no differences between the groups. There was a significant increase in total creatine concentration following creatine supplementation, with the group ingesting α-lipoic acid showing a significantly greater increase (p < .05) in phosphocreatine (87.6 → 106.2 mmol · kg−1 dry mass [dm]) and total creatine (137.8 → 156.8 mmol · kg−1 dm). These findings indicate that co-ingestion of α-lipoic acid with creatine and a small amount of sucrose can enhance muscle total creatine content as compared to the ingestion of creatine and sucrose or creatine alone.
Influence of Carbohydrate Ingestion on Cytokine Responses Following Acute Resistance Exercise
Authors: Chan Marcia A. , Koch Alexander J. , Benedict Stephen H. , Potteiger Jeffrey A.
Published: August 2016

The effect of carbohydrate supplementation (CHO) on interleukin 2 (IL-2) and interleukin 5 (IL-5) secretion following acute resistance exercise was examined in 9 resistance-trained males. Subjects completed a randomized, double-blind protocol with exercise separated by 14 days. The exercise consisted of a high intensity, short rest interval squat workout. Subjects consumed 1.0 g · kg body mass-1 CHO or an equal volume of placebo (PLC) 10 min prior to and 10 min following exercise. Blood was collected at rest (REST), immediately post exercise (POST), and at 1.5 h of recovery (1.5 h POST). Isolated peripheral blood mononuclear cells were stimulated with PHA and assayed for IL-2 and IL-5 secretion. IL-2 secretion was significantly decreased at POST for both the PLC and CHO groups. However, the degree of decrease was less in the CHO group (16%) than in the PLC group (48%), and this difference was statistically significant. These responses were transient, and the values returned to normal by 1.5 h POST. A mild and transient but significant decrease in IL-5 secretion by the PLC group was observed at POST (26%) compared to REST. No significant decrease was observed in IL-5 secretion for CHO from REST to POST (12%). These data support a possible effect of carbohydrate supplementation on IL-2 and IL-5 secretion following high-intensity resistance exercise.
The Influence of Low versus High Carbohydrate Diet on a 45-min Strenuous Cycling Exercise
Authors: Kavouras Stavros A. , Troup John P. , Berning Jacqueline R.
Published: August 2016

To examine the effects of a 3-day high carbohydrate (H-CHO) and low carbohydrate (L-CHO) diet on 45 min of cycling exercise, 12 endurance-trained cyclists performed a 45-min cycling exercise at 82 ± 2% VO2peak following an overnight fast, after a 6-day diet and exercise control. The 7-day protocol was repeated under 2 randomly assigned dietary trials H-CHO and L-CHO. On days 1–3, subjects consumed a mixed diet for both trials and for days 4–6 consumed isocaloric diets that contained either 600 g or 100 g of carbohydrates, for the HCHO and the L-CHO trials, respectively. Muscle biopsy samples, taken from the vastus lateralis prior to the beginning of the 45-min cycling test, indicated that muscle glycogen levels were significantly higher (p < .05) for the H-CHO trial (104.5 ± 9.4 mmol/kg wet wt) when compared to the L-CHO trial (72.2 ± 5.6 mmol/kg wet wt). Heart rate, ratings of perceived exertion, oxygen uptake, and respiratory quotient during exercise were not significantly different between the 2 trials. Serum glucose during exercise for the H-CHO trial significantly increased (p < .05) from 4.5 ± 0.1 mmol · L−1 (pre) to 6.7 ± 0.6 mmol · L−1 (post), while no changes were found for the L-CHO trial. In addition, post-exercise serum glucose was significantly greater (p < .05) for the H-CHO trial when compared to the L-CHO trial (H-CHO, 6.7 ± 0.6 mmol · L−1; L-CHO, 5.2 ± 0.2 mmol · L−1). No significant changes were observed in serum free fatty acid, triglycerides, or insulin concentration in either trial. The findings suggest that L-CHO had no major effect on 45-min cycling exercise that was not observed with H-CHO when the total energy intake was adequate.
One Year of Oral Calcium Supplementation Maintains Cortical Bone Density in Young Adult Female Distance Runners
Authors: Winters-Stone Kerri M. , Snow Christine M.
Published: August 2016

We conducted a double-blind, placebo-controlled, randomized trial to determine whether 1 year of supplemental calcium intake would augment hip [greater trochanter, GT, femoral neck (FN), total hip (TH)], spine (LS), and femoral mid-shaft (Fmr) BMD in female distance runners. Twenty-three women (age: 23.7 ± 4.7 yrs, height: 165.6 ± 6.3 cm, weight: 55.7 ± 6.1 kg) were randomly assigned to receive either 1000 mg/d of supplemental calcium (N = 13) or placebo tablets (N = 10) for 1 year. BMD was determined by DXA (Hologic 1000-W) and tablet compliance by self-report logs. Compliance averaged 79% and 71% for supplement and placebo groups, respectively. Calcium supplementation did not affect hip or spine BMD, but did prevent loss at the femoral mid-shaft (GT: –0.5% vs. 0.2%, FN: 0.9% vs. 1.1%, TH: –0.3% vs. 0.2%, LS: 0.3% vs. 1.2%, Fmr: 0.1% vs. –1.8%, for calcium vs. placebo, respectively). We conclude that the addition of 800 mg/d of supplemental calcium to the diet of young adult female distance runners with habitual calcium intakes of ~1000 mg/d, prevents cortical but not trabecular bone loss.
Metabolic Effects of the Addition of Resistive to Aerobic Exercise in Older Men
Authors: Ferrara Cynthia M. , McCrone Susan H. , Brendle David , Ryan Alice S. , Goldberg Andrew P.
Published: August 2016

The metabolic changes associated with the addition of 4 months of resistive exercise to an existing aerobic exercise program (AEX+RT, n = 7) were compared to a maintenance aerobic exercise program (AEX, n = 8) in overweight, older men. The subjects in this study had recently completed a 6-month aerobic exercise program (treadmill walking, 45 min/d, 2 d/wk). The AEX+RT group added 6 exercises on upper- and lower-body pneumatic-resistance machines (2 sets, 15 repetitions each, 2 d/wk) to an aerobic exercise program at ≥ 70% heart rate reserve for 30–40 min, 2 d/wk on treadmill, while the AEX group continued the same maintenance treadmill AEX program. There were no baseline differences in body weight, VO2max, or glucose metabolism between groups. The AEX+RT group increased upper- and lower-extremity strength by 28 ± 4% and 46 ± 6%, respectively (p < .05), despite a 9% decrease in VO2max (p < .05). VO2max did not change in the AEX group. There was no change in the fasting glucose or insulin levels, or the 3-h glucose responses to an oral glucose load in either group. The insulin responses decreased by 25 ± 4% in the AEX+RT group (p < .01) but did not change in the AEX group. In conclusion, the addition of resistive exercise training to an existing aerobic exercise program may improve insulin sensitivity in overweight, older men, and thus prevent the development of type 2 diabetes.
Nutritional Status of Brazilian Elite Swimmers
Authors: Paschoal Valéria Cristina Provenza , Amancio Olga Maria Silverio
Published: August 2016

The purpose of this study was to evaluate the body composition, dietary intake, use of nutritional supplements, and biochemical status of 8 Brazilian male elite swimmers, aged 18–21 years, participants at a national swimming competition. Data from the athletes were obtained through a 4-day food record, a fasting blood sample, and anthropometric measurements. The anthropometric results showed that body composition was compatible with sport category. The dietary assessment showed an adequate ingestion of calories, vitamins, and mineral, with the exception of calcium, for which only half of the sample reached the recommendation. The results also indicated low carbohydrate and high protein and cholesterol intakes. Of the swimmers, 62.5% and 25% consumed synthetic aminoacids and antioxidants supplements, respectively. The biochemical indices of the nutritional status were within normal limits in all swimmers, with the exception of creatine-kinase, which was above the recommended level, indicating muscle degradation probably due to poor carbohydrate intake. In conclusion, the results suggest the importance of nutritional education to promote a balanced intake, provide all nutrients in optimal amounts, inhibit unnecessary ingestion of nutritional supplements, maintain ideal performance, and improve the swimmers’ health status.
Bone Mineral Density in Young Active Females: The Case of Dancers
Authors: Yannakoulia Mary , Keramopoulos Antonios , Matalas Antonia-Leda
Published: August 2016

The aim of the study was to evaluate the combined effect of several environmental factors on bone mineral density (BMD) in a group of highly active young women. Body composition, total body and regional (arms, legs and trunk) BMD, dietary intake, menstrual status, training habits, and eating attitudes were assessed in 37 professional dance students, aged 18 to 26 years. Dancers had higher BMD values compared to age- and weight-matched reference population (mean total body BMD: 1.185 g/cm2, 9% higher than reference values). No differences were detected between currently eumenorrheic and noneumenorrheic dancers; subjects who encountered menstrual problems during adolescence had significantly lower BMD values compared to counterparts who did not. Regarding dietary intake, dancers in the highest quartile of calcium intake (1323 ±113 mg/d) exhibited significantly higher total BMD values than subjects in the other 3 quartiles (p = .04). A moderate inverse relationship was found between protein intake and total BMD, after controlling for energy and calcium intake (r = -0.37). Fat-free soft mass was the only significant predictor of total BMD, explaining 20% of the variance. High levels of calcium intake were associated with high total BMD values. These results confirm the beneficial role of long-term and intensive physical activity on BMD and further suggest that dancers are not at a greater risk compared to the general population for developing osteoporosis, despite their menstrual and eating problems.
Influence of Carbohydrate and Age on Lymphocyte Function Following a Marathon
Authors: Henson Dru A. , Nieman David C. , Pistilli E. Edward , Schilling Brian , Colacino AnnaRita , Utter Allan C. , Fagoaga Omar R. , Vinci Debra M. , Nehlsen-Cannarella Sandra L.
Published: August 2016

The influence of 6% carbohydrate ingestion and age on PHA-induced lymphocyte proliferation and in vitro cytokine production was studied in 48 runners following a competitive marathon. Runners were randomly assigned to carbohydrate (C; n = 23) and placebo (P; n = 25) groups, with blood samples taken before, immediately after, and 1.5 hr post-race. C versus P ingestion resulted in higher plasma glucose, lower plasma corlisol, reduced neutrophilia, and mono-cytosis during recovery, but had no effect on the post-exercise reduction in T-lymphocytes or NK cells, or on race times. No group differences were observed for PHA-induced lymphocyte proliferation or cytokine production. However, for all subjects combined, lymphocyte proliferation and IFN-γ secretion decreased significantly below pre-race values by 1.5 hr of recovery, and these were negatively correlated with plasma cortisol. Young (<50 years; n = 36) and old (≥50 years; n = 12) runners exhibited parallel post-race declines in lymphocyte proliferation and IFN-γ secretion, with the older group exhibiting a 33–59% lower proliferation at each time point. In conclusion, PHA-induced lymphocyte proliferation and cytokine production decreased significantly following a marathon, and this decrease was strongly linked to cortisol and only partially linked to T-cell changes. This decrease occurred in both younger and older runners and was not influenced by carbohydrate.
Effects of Antioxidant Therapy in Women Exposed to Eccentric Exercise
Authors: Bloomer Richard J.
Published: August 2016

The purpose of this study was to determine the effects of antioxidant therapy on indirect markers of muscle damage following eccentric exercise (EE). Eighteen women were randomized to an antioxidant supplement or a placebo before a bout of EE. Plasma creatine kinase (CK) activity, muscle soreness (MS), maximal isometric force (MIF), and range of motion (ROM) were assessed before and through 14 d postexercise. Eccentric exercise resulted in an increase in CK activity and MS, and a drop in MIF and ROM during the days following EE, which returned to baseline values 14 d after EE in both groups. Antioxidants attenuated the CK activity and MS response to the EE, while little difference was noted between groups in MIF or ROM. These fndings suggest that antioxidant supplementation was helpful in reducing the elevations in plasma CK activity and MS, with little impact on MIF and ROM loss.
Nutrient Intakes and Dietary Behaviors of Male and Female Collegiate Athletes
Authors: Hinton Pamela S. , Sanford Tiffany C. , Davidson M. Meghan , Yakushko Oksana F. , Beck Niels C.
Published: August 2016

The purpose of this study was to assess the dietary intakes and behaviors of male and female collegiate athletes. Athletes (n = 345) at a NCAA Division I university completed an anonymous questionnaire. T-tests, χ2 statistic and ANOVA were used to assess gender and sport differences. Multiple linear regression was used to assess gender differences in nutrient intakes, controlling for energy intake and to examine the relationships between desired weight change, dietary behaviors, and nutrient intakes. Only 15% and 26% of athletes had adequate intakes of carbohydrate and protein, respectively, based on recommendations for athletes. Males were more likely to exceed the Dietary Guidelines for fat, saturated fat, cholesterol, and sodium than females. Sixty-two percent of female athletes wanted to lose at least 5 lbs compared to 23% of males. The desire to lose weight was associated with decreased energy and macronutrient consumption, but not with inadequate micronutrient intakes.
Skeletal Muscle Total Creatine Content and Creatine Transporter Gene Expression in Vegetarians Prior to and Following Creatine Supplementation
Authors: Watt Kenneth K.O. , Garnham Andrew P. , Snow Rodney J.
Published: August 2016

This study examined the effect of vegetarianism on skeletal muscle total creatine (TCr) content and creatine transporter (CreaT) gene expression, prior to and during 5 d of Cr supplementation (CrS). In a double-blind, crossover design, 7 vegetarians (VEG) and nonvegetarians (NVEG) were assigned Cr or placebo supplements for 5 d and after 5 wk, received the alternative treatment. Muscle sampling occurred before, and after 1 and 5 d of treatment ingestion. Basal muscle TCr content was lower (P < 0.05) in VEG compared with NVEG. Muscle TCr increased (P < 0.05) throughout the Cr trial in both groups but was greater (P < 0.05) in VEG compared with NVEG, at days 1 and 5. CreaT gene expression was not different between VEG and NVEG. The results indicate that VEG have a lower muscle TCr content and an increased capacity to load Cr into muscle following CrS. Muscle CreaT gene expression does not appear to be affected by vegetarianism.
Dietary Intake and Nutritional Practices of Elite Greek Aquatic Athletes
Authors: Farajian P. , Kavouras S.A. , Yannakoulia M. , Sidossis L.S.
Published: August 2016

To investigate whether aquatic athletes follow optimal dietary intake, 58 athletes, all members of the Greek national swimming and water polo teams, were tested. Dietary intake was assessed at the nutrient, food, and food group level using the 24-h recall method and a food frequency questionnaire. Mean energy intake for males and females was 14.3 and 8.5 MJ, respectively. Mean carbohydrate consumption for male and female athletes was 4.5 g/kg and 3.8 g/kg of body weight, respectively. Fat intake was 153 g for males and 79 g for females. A significant number of the athletes (71% of the males, 93% of the females) did not meet the Dietary Reference Intakes for at least one of the antioxidant vitamins. The data suggest that athletes of both genders consumed too much fat and too little carbohydrate. Insufficient fruit and vegetable intake was related to low intake of antioxidants.
Gastrointestinal Discomfort during Intermittent High-Intensity Exercise: Effect of Carbohydrate–Electrolyte Beverage
Authors: Shi Xiaocai , Horn Mary K. , Osterberg Kris L. , Stofan, John R. , Zachwieja Jeffrey J. , Horswill Craig A. , Passe Dennis H. , Murray Robert
Published: August 2016

This study investigated whether different beverage carbohydrate concentration and osmolality would provoke gastrointestinal (GI) discomfort during intermittent, high-intensity exercise. Thirty-six adult and adolescent athletes were tested on separate days in a double-blind, randomized trial of 6% and 8% carbohydrate-electrolytes (CHO-E) beverages during four 12-min quarters (Q) of circuit training that included intermittent sprints, lateral hops, shuttle runs, and vertical jumps. GI discomfort and fatigue surveys were completed before the first Q and immediately after each Q. All ratings of GI discomfort were modest throughout the study. The cumulative index for GI discomfort, however, was greater for the 8% CHO-E beverage than for the 6% CHO-E beverage at Q3 and Q4 (P < 0.05). Averaging across all 4 quarters, the 8% CHO-E treatment produced significantly higher mean ratings of stomach upset and side ache. In conclusion, higher CHO concentration and osmolality in an ingested beverage provokes stomach upset and side ache.
Comparison of Erythrocyte and Skeletal Muscle Creatine Accumulation Following Creatine Loading
Authors: Preen David B. , Dawson Brian T. , Goodman Carmel , Beilby John , Ching Simon
Published: August 2016

This study attempted to determine the relationship between creatine (Cr) accumulation in human skeletal muscle and erythrocytes following Cr supplementation. If a strong relationship exists, a blood test might provide a practical, less invasive alternative than muscle biopsy for evaluating cellular Cr accumulation. Eighteen active, but not well-trained males were supplemented with Cr (4 × 5g/d) for 5 d. Muscle biopsies (vastus lateralis) were obtained pre- and post-loading and analyzed for Cr, phosphocreatine (PCr), and total Cr (TCr) content. Venous blood was also drawn at these times to determine erythrocyte Cr concentrations. Muscle Cr, PCr, and TCr concentrations were elevated (P < 0.05) by 39.8%, 7.5%, and 20.1% respectively following supplementation. Erythrocyte Cr concentrations were also elevated (P < 0.01) following the loading period, although to a greater relative degree than tissue concentrations (129.6%). Pre- and post-loading erythrocyte Cr concentrations were poorly and nonsignificantly correlated with that observed in skeletal muscle. Further, loading-mediated increases in erythrocyte Cr concentrations were poorly correlated with elevations in muscle Cr (r = 0.07), PCr (r = 0.06) or TCr (r = 0.04) concentrations. Erythrocyte Cr concentrations can be augmented by 5 d of Cr supplementation, however, this elevation does not reflect that observed in skeletal muscle obtained by muscle biopsy. Consequently, erythrocyte response to Cr loading is not a reliable measure of skeletal muscle Cr/TCr accumulation.
Accuracy of Urine Specific Gravity and Osmolality as Indicators of Hydration Status
Authors: Oppliger Robert A. , Magnes Scott A. , Popowski LeRoy A. , Gisolfi Carl V.
Published: August 2016

To reduce the adverse consequences of exertion-related and acute intentional dehydration research has focused on monitoring hydration status. This investigation: 1) compared sensitivity of urine specific gravity (Usg), urine osmolality (Uosm) and a criterion measurement of hydration, plasma osmolality (Posm), at progressive stages of acute hypertonic dehydration and 2) using a medical decision model, determined whether Usg or Uosm accurately reflected hydra-tion status compared to Posm among 51 subjects tested throughout the day. Incremental changes in Posm were observed as subjects dehydrated by 5% of body weight and rehydrated while Usg and Uosm showed delayed dehydration-related changes. Using the medical decision model, sensitivity and specificity were not significant at selected cut-offs for Usg and Uosm. At the most accurate cut-off values, 1.015 and 1.020 for Usg and 700 mosm/kg and 800 mosm/kg for Uosm, only 65% of the athletes were correctly classified using Usg and 63% using Uosm. Posm, Usg, and Uosm appear sensitive to incremental changes in acute hypertonic dehydration, however, the misclassified outcomes for Usg and Uosm raise concerns. Research focused on elucidating the factors affecting accurate assessment of hydration status appears warranted.
The Metabolic Responses to High Carbohydrate Meals with Different Glycemic Indices Consumed during Recovery from Prolonged Strenuous Exercise
Authors: Stevenson Emma , Williams Clyde , Biscoe Helen
Published: August 2016

This study investigated the metabolic responses to high glycemic index (HGI) or low glycemic index (LGI) meals consumed during recovery from prolonged exercise. Eight male, trained athletes undertook 2 trials. Following an overnight fast, subjects completed a 90-min run at 70% VO2max. Meals were provided 30 min and 2 h following cessation of exercise. The plasma glucose responses to both meals were greater in the HGI trial compared to the LGI trial (P < 0.05). Following breakfast, there were no differences in the serum insulin concentrations between the trials; however, following lunch, concentrations were higher in the HGI trial compared to the LGI trial (P < 0.05). This suggests that the glycemic index of the carbohydrates consumed during the immediate post-exercise period might not be important as long as sufficient carbohydrate is consumed. The high insulin concentrations following a HGI meal later in the recovery period could facilitate further muscle glycogen resynthesis.
Astaxanthin Supplementation Does Not Attenuate Muscle Injury Following Eccentric Exercise in Resistance-Trained Men
Authors: Bloomer Richard J. , Fry Andrew , Schilling Brian , Chiu Loren , Hori Naruhiro , Weiss Lawrence
Published: August 2016

This investigation was designed to determine the effects of astaxanthin on markers of skeletal muscle injury. Twenty resistance trained men (mean ± standard error of the mean: age, 25.1 ± 1.6 y; height, 1.79 ± 0.02 m; weight, 86.8 ± 4.4 kg) were assigned to either a placebo (1732 mg safflower oil, n = 10) or astaxanthin (BioAstin; 1732 mg safflower oil; haematococcus algae extract [contains 4 mg astaxanthin and 480 mg lutein], n = 10). Subjects consumed their assigned treatment for 3 wk prior to eccentric exercise (10 sets of 10 repetitions at 85% of one repetition maximum) and through 96 h post-exercise. Muscle soreness, creatine kinase (CK), and muscle performance was measured before and through 96 h post-exercise. A similar response was observed for both treatment groups for all dependent variables, indicating that in resistance trained men, astaxanthin supplementation does not favorably affect indirect markers of skeletal muscle injury following eccentric loading.
A Comparison of Pre-Competition Eating Patterns in a Group of Non-Elite Triathletes
Authors: Robins Anna , Hetherington Marion M.
Published: August 2016

A qualitative research study investigated food choice by triathletes prior to training and competition, and gauged attitudes towards nutritional management. Five focus groups were conducted with 7 male and 6 female non-elite triath-letes. Sessions were semi-structured, tape recorded, and transcribed verbatim for coding and analysis. Transcripts were coded using grounded theory and higher order themes emerged including: “somatic complaints,” “performance,” “trust,” “preferences,” and “routine.” Food choices, especially those of the more competitive triathletes, were made to maximize performance. Choices were based on past experience and “trial and error” rather than specialist advice. Subjects varied in nutritional knowledge, which appeared to relate to the level of competitiveness. More competitive triathletes were interested in improving performance but distrusted others making their nutritional choices. Less competitive triathletes embraced nutritional manipulation for gains in cognitive and athletic performance. “Trust” became a focus of the study and warrants further investigation, as this is a crucial component of providing nutritional advice to competitive athletes and to the general population.
Iron Deficiency and Anemia: A Common Problem in Female Elite Soccer Players
Authors: Landahl Göran , Adolfsson Peter , Börjesson Mats , Mannheimer Clas , Rödjer Stig
Published: August 2016

The objective of the study was to determine the prevalence of iron deficiency and iron deficiency anemia among elite women soccer players. Hemoglobin, serum iron, serum total iron binding capacity, and ferritin were determined in 28 female soccer players called up for the national team. Of the investigated female soccer players, 57% had iron deficiency and 29% iron deficiency anemia 6 months before the FIFA Women’s World Cup. It is concluded that iron deficiency and iron deficiency anemia is common in female soccer players at the top international level. Some might suffer from relative anemia and measurement of hemoglobin alone is not sufficient to reveal relative anemia. Regular monitoring of hemoglobin concentration and iron status is necessary to institute iron supplementation when indicated.
The Prevalence of Disordered Eating, Menstrual Dysfunction, and Low Bone Mineral Density among US Collegiate Athletes
Authors: Beals Katherine A. , Hill Amanda K.
Published: August 2016

The purpose of this study was to examine the prevalence of disordered eating (DE), menstrual dysfunction (MD), and low bone mineral density (BMD) among US collegiate athletes (n = 112) representing 7 different sports (diving, swimming, x-country, track, tennis, field hockey, and softball) and determine differences in prevalence existed between athletes participating in lean-build (LB) and non-lean build (NLB) sports. DE and MD were assessed by a health, weight, dieting, and menstrual history questionnaire. Spinal BMD was determined via dual energy x-ray absorptiometry. Twenty-eight athletes met the criteria for DE, twenty-nine for MD, and two athletes had low BMDs (using a Z score below −2.0). Ten athletes met the criteria for two disorders (one with disordered eating and low BMD and nine with disordered eating and menstrual dysfunction), while only one athlete met the criteria for all three disorders. Using a Z score below −1.0, two additional athletes met the criteria for all three disorders and three more athletes met the criteria for a combination of two disorders. With the exception of MD, which was significantly more prevalent among LB vs. NLB sports (P = 0.053), there were no differences between the groups in the prevalence of individual disorders or combinations of disorders. These data indicate that the combined prevalence of DE, MD, and low BMD among collegiate athletes is small; however, a significant number suffer from individual disorders of the Triad.
Body Composition, Dietary Intake, and Iron Status of Female Collegiate Swimmers and Divers
Authors: Petersen Heidi L. , Peterson C. Ted , Reddy Manju B. , Hanson Kathy B. , Swain James H. , Sharp Rick L. , Alekel D. Lee
Published: August 2016

This study determined the effect of training on body composition, dietary intake, and iron status of eumenorrheic female collegiate swimmers (n = 18) and divers (n = 6) preseason and after 16 wk of training. Athletes trained on dryland (resistance, strength, fexibility) 3 d/wk, 1.5 h/d and in-water 6 d/wk, nine, 2-h sessions per week (6400 to 10,000 kJ/d). Body-mass index (kg/m2; P = 0.05), waist and hip circumferences (P ≤ 0.0001), whole body fat mass (P = 0.0002), and percentage body fat (P ≤ 0.0001) decreased, whereas lean mass increased (P = 0.028). Using dual-energy X-ray absorptiometry, we found no change in regional lean mass, but fat decreased at the waist (P = 0.0002), hip (P = 0.0002), and thigh (P = 0.002). Energy intake (10,061 ± 3617 kJ/d) did not change, but dietary quality improved with training, as refected by increased intakes of fber (P = 0.036), iron (P = 0.015), vitamin C (P = 0.029), vitamin B-6 (P = 0.032), and fruit (P = 0.003). Iron status improved as refected by slight increases in hemoglobin (P = 0.046) and hematocrit (P = 0.014) and decreases in serum transferrin receptor (P ≤ 0.0001). Studies are needed to further evaluate body composition and iron status in relation to dietary intake in female swimmers.
Serum Basal Hormone Concentrations and Muscle Mass in Aging Women: Effects of Strength Training and Diet
Authors: Sallinen Janne , Pakarinen Arto , Fogelholm Mikael , Sillanpää Elina , Alen Markku , Volek Jeff S. , Kraemer William J. , Häkkinen Keijo
Published: August 2016

This study examined the effects of strength training and diet on serum basal hormone concentrations and muscle mass in aging women. Fifty-one women age 49 to 74 y were divided into two groups: strength training and nutritional counseling (n = 25), and strength training (n = 26). Both groups performed strength training twice a week for 21 wk. Nutritional counseling was given to attain sufficient energy and protein intake and recommended intake of fat and fiber. We found that the cross-sectional area of the quadriceps femoris increased by 9.5 ± 4.1% in the nutritional counseling group versus 6.8 ± 3.5% in the strength training only group after training (P < 0.052). Nutritional counseling evoked dietary changes such as increases in the proportion of energy from protein and the ratio of poly-unsaturated and saturated fatty acids. Strength training increased testosterone and testosterone/sex hormone-binding globulin ratio after the first half of training, but these returned to baseline values at the end of the entire training period. Changes in serum basal hormone concentrations did not differ between the groups. Our results support the conclusion that nutritional counseling can contribute to the increase in the muscle cross-sectional area during prolonged strength training in aging women.
Exercise, Nutrition, and Homocysteine
Authors: Joubert Lanae M. , Manore Melinda M.
Published: August 2016

Homocysteine is an independent cardiovascular disease (CVD) risk factor modi-fable by nutrition and possibly exercise. While individuals participating in regular physical activity can modify CVD risk factors, such as total blood cholesterol levels, the impact physical activity has on blood homocysteine concentrations is unclear. This review examines the influence of nutrition and exercise on blood homocysteine levels, the mechanisms of how physical activity may alter homocys-teine levels, the role of homocysteine in CVD, evidence to support homocysteine as an independent risk factor for CVD, mechanisms of how homocysteine increases CVD risk, and cut-off values for homocysteinemia. Research examining the impact of physical activity on blood homocysteine levels is equivocal, which is partially due to a lack of control for confounding variables that impact homocysteine. Duration, intensity, and mode of exercise appear to impact blood homocysteine levels differently, and may be dependent on individual fitness levels.
Protein Intake for Skeletal Muscle Hypertrophy with Resistance Training in Seniors
Authors: Andrews Ryan D. , MacLean David A. , Riechman Steven E.
Published: August 2016

Variability in protein consumption may influence muscle mass changes induced by resistance exercise training (RET). We sought to administer a post-exercise protein supplement and determine if daily protein intake variability affected variability in muscle mass gains. Men (N = 22) and women (N = 30) ranging in age from 60 to 69 y participated in a 12-wk RET program. At each RET session, participants consumed a post-exercise drink (0.4 g/kg lean mass protein). RET resulted in significant increases in lean mass (1.1 ±1.5 kg), similar between sexes (P > 0.05). Variability in mean daily protein intake was not associated with change in lean mass (r < 0.10, P > 0.05). The group with the highest protein intake (1.35 g · kg−1 · d−1, n = 8) had similar (P > 0.05) changes in lean mass as the group with the lowest daily protein intake (0.72 g · kg−1 · d−1, n = 9). These data suggest that variability in total daily protein intake does not affect variability in lean mass gains with RET in the context of post-exercise protein supplementation.
Dietary Antioxidant Supplementation Combined with Quercetin Improves Cycling Time Trial Performance
Authors: MacRae Holden S-H. , Mefferd Kari M.
Published: August 2016

We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline TT (B). MANOVA analysis showed that time to complete the 30 km TT was improved by 3.1% on FRS compared to B (P ≤ 0.01), and by 2% over the last 5 km (P ≤ 0.05). Absolute and relative (%HRmax) heart rates and percent VO2max were not different between trials, but average and relative power (% peak power) was higher on FRS (P ≤ 0.01). Rates of carbohydrate and fat oxidation were not different between trials. Thus, FRS supplementation significantly improved high-intensity cycling TT performance through enhancement of power output. Further study is needed to determine the potential mechanism(s) of the antioxidant efficacy.
Caffeinated Sports Drink: Ergogenic Effects and Possible Mechanisms
Authors: Cureton Kirk J. , Warren Gordon L. , Millard-Stafford Mindy L. , Wingo Jonathan E. , Trilk Jennifer , Buyckx Maxime
Published: August 2016

This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. Sixteen highly trained cyclists completed 3 trials: placebo, carbohydrate-electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the first 120 min, followed by a 15-min performance ride. Maximal voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15–23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5% vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.
Preexercise Carbohydrate Consumption and Repeated Anaerobic Performance in Pre- and Early-Pubertal Boys
Authors: Marjerrison Andrea D. , Lee Jonah D. , Mahon Anthony D.
Published: August 2016

This study examined the effect of pre exercise carbohydrate (CHO) feeding on performance on a Wingate anaerobic test (WAnT) in 11 boys (10.2 ± 1.3 y old). Four WAnTs with 2 min recovery were performed 30 min after consuming a CHO (1 g CHO/kg) or placebo drink. Peak power (PP) and mean power (MP) were similar between trials. PP ranged from 241.1 ± 82.2 to 223.1 ± 57.9 W with carbohydrate and from 238.2 ± 76.1 to 223.4 ± 52.3 W with placebo. MP ranged from 176.3 ± 58.4 to 151.1 ± 37.5 W with carbohydrate versus 178.0 ± 45.8 to 159.1 ± 32.7 W with placebo. Pre exercise glucose was significantly higher in CHO versus placebo (7.0 ± 1.0 vs. 5.5 ± 0.5 mmol/L), but post exercise values were not different. Blood lactate was similar between trials but increased over time. This study found that the ingestion of a CHO solution before exercise did not influence power output during repeated performances of the WAnT.
Does Sodium-Bicarbonate Ingestion Improve Simulated Judo Performance?
Authors: Artioli Guilherme Giannini , Gualano Bruno , Coelho Desiré Ferreira , Benatti Fabiana Braga , Gailey Alessandra Whyte , Lancha Antonio Herbert
Published: August 2016

The aim of the present study was to investigate whether pre exercise sodium-bicarbonate ingestion improves judo-related performance. The study used 2 different protocols to evaluate performance: 3 bouts of a specific judo test (n = 9) and 4 bouts of the Wingate test for upper limbs (n = 14). In both protocols athletes ingested 0.3 g/kg of sodium bicarbonate or placebo 2 h before the tests. Blood samples were collected to determine lactate level, and levels of perceived exertion were measured throughout the trials. The study used a double-blind, counterbalanced, crossover design. Ingestion of sodium bicarbonate improved performance in Bouts 2 and 3 of Protocol 1 (P < 0.05), mean power in Bouts 3 and 4 of Protocol 2 (P < 0.05), and peak power in Bout 4 of Protocol 2 (P < 0.05). Ingestion of bicarbonate increased lactate concentration in Protocol 1 (P < 0.05) but not in Protocol 2. Ratings of perceived exertion did not differ between treatments. In conclusion, sodium bicarbonate improves judo-related performance and increases blood lactate concentration but has no effect on perceived exertion.
Gastric Emptying of Fluids during Variable-Intensity Running in the Heat
Authors: Gant Nicholas , Leiper John B. , Williams Clyde
Published: August 2016

This study examined gastric emptying, core temperature, and sprint performance during prolonged intermittent shuttle running in 30 °C when ingesting a carbohydrate-electrolyte solution (CES) or favored water (FW). Nine male soccer players performed 60 min of shuttle running, ingesting fluid before exercise and every 15 min during exercise. Gastric emptying was measured using a double-sampling aspiration technique, and intestinal temperature was monitored via ingested capsules. There were no differences between trials in the total fluid volume emptied from the stomach during each exercise period (P = 0.054). The volume emptied every 15 min was 244 ± 67 mL in the CES trial and 273 ± 66 mL in the FW trial. Intestinal temperature was higher during exercise in the CES trial (P = 0.004), and cumulative sprint time was shorter (P = 0.037). Sprint performance was enhanced by the ingestion of a CES, which resulted in elevated core temperatures, and the rate of gastric emptying remained similar between solutions.
Carbohydrate-Gel Supplementation and Endurance Performance during Intermittent High-Intensity Shuttle Running
Authors: Patterson Stephen D. , Gray Susan C.
Published: August 2016

The aim of this study was to investigate the effects of a carbohydrate (CHO) gel on performance after prolonged intermittent high-intensity shuttle running. Seven male soccer players performed 2 exercise trials, 7 d apart. On each occasion, participants completed five 15-min periods of intermittent variable-speed running, interspersed with periods of walking (Part A), followed by an intermittent run to exhaustion (Part B). Participants consumed either a CHO gel or placebo (PLA) immediately before exercise (0.89 mL/kg body mass [BM]) and every 15 min thereafter (0.35 mL/kg BM). In addition, water was consumed at a rate of 5 mL/kg BM before and 2 mL/kg BM every 15 min during exercise. Blood glucose levels were higher (P < 0.05) at 15, 30, and 60 min of exercise and at exhaustion in CHO than in PLA. During Part B, run time to exhaustion was longer (P < 0.05) in the CHO trial (CHO 6.1 ± 1.3 min vs. PLA 4.2 ± 1.2 min). These results indicate that ingesting a CHO gel, along with water, improves performance after prolonged intermittent running in healthy male subjects, possibly by maintaining blood glucose levels during exercise.
A Systematic Review on Use of a Handheld Indirect Calorimeter to Assess Energy Needs in Adults and Children
Authors: McDoniel Scott O.
Published: August 2016

With the number of individuals becoming overweight or obese, health care professionals are in need of accurate, reliable, and convenient tools to help personalize weight-loss programs. Recently, a new handheld indirect calorimeter (i.e., MedGem/BodyGem; also know as “Gem”) was introduced as a convenient way to assess resting metabolic rate (RMR) to determine daily energy needs. Several validation and comparison studies were conducted to determine whether the Gem device is accurate and reliable, and results from these studies are mixed. Fourteen human studies (12 adult, 2 pediatric) were conducted, and 12 met the established criteria for this review. In all Douglas-bag (DB; n = 4) validation studies, the Gem device was not significantly different than the DB (mean difference adult ±1%, pediatric ±1%). The intra class reliability of the Gem ranged from 0.97 to 0.98, and the interclass reliability to the DB ranged from 0.91 to 0.97. Although few (n = 2) studies have demonstrated that the Gem device measures RMR significantly lower (–8.2% to 15.1%) than traditional metabolic carts, it performs very comparably (RMR values 0.1–4.0%, interclass reliability 0.76–0.92) to traditional metabolic carts in most (n = 6) of the comparison studies. Based on these data, the Gem device is a valid and reliable indirect calorimeter for energy assessment in most adults and children.
Effect of Carbohydrate Intake during Recovery from Eccentric Exercise on Interleukin-6 and Muscle-Damage Markers
Authors: Miles Mary P. , Pearson Sherri D. , Andring Jan M. , Kidd Jessy R. , Volpe Stella L.
Published: August 2016

The purpose of this investigation was to determine whether carbohydrate supplementation during the frst 2 d post exercise recovery influenced the inflammation (IL-6, C-reactive protein [CRP], and cortisol) and muscle-damage responses. Eight participants performed a high-force eccentric elbow-fexion exercise to induce muscle soreness and inflammation and then consumed carbohydrate (0.25 g·kg−1·h−1) or an equal volume of placebo during hours 0–12 and 24–36 post exercise in a double-blind, crossover protocol. Muscle soreness; mid brachial arm circumference; blood glucose, IL-6, CRP, cortisol, and creatine-kinase (CK) activity; and maximal force production were measured pre exercise and 4, 8, 12, 24, 48, and 120 h post exercise. Plasma IL-6 increased, F(5) = 5.27, P < 0.05, 8 h post exercise, with no difference between carbohydrate and placebo conditions. Changes in muscle soreness, arm circumference, strength, and serum CK activity were consistent with small amounts of muscle damage and did not differ between conditions. The authors conclude that carbohydrate supplementation during recovery from soreness-inducing exercise does not influence the delayed IL-6 response temporally linked to inflammation or indications of muscle damage. Thus, increased carbohydrate consumption at levels consistent with recommendations for replenishing glycogen stores does not impair or promote the immune and muscle responses.