Dan Benardot | Emory University (original) (raw)
Papers by Dan Benardot
HSOA journal of physical medicine, rehabilitation & disabilities, May 16, 2024
Occupational Health and Industrial Medicine, 1999
The nutrient intakes and dietary practices of elite, U.S. national team, artistic female gymnasts... more The nutrient intakes and dietary practices of elite, U.S. national team, artistic female gymnasts (n = 33) were evaluated using 3-day food records. The gymnasts' reported energy intake was 34.4 kcal/kg (total 1,678 kcal/day), which was 20% below the estimated energy requirement. The contributions of protein, fat, and carbohydrate to total energy intake were 17%, 18%, and 66%, respectively. All reported vitamin intakes, except vitamin E, were above the RDA. The reported mineral intakes, especially calcium, zinc, and magnesium, were less than 100% of the RDA. The overall nutrient densities of the subjects' diets were higher than expected. Eighty-two percent of the gymnasts reported taking nonprescription vitamin and mineral supplements, and 10% reported taking prescription vitamin and mineral supplements. Forty-eight percent of the gymnasts reported being on a self-prescribed diet. Compared to NHANES III, the reported nutrient intake of these gymnasts was different from that of the average U.S. adolescent female. In summary, certain key nutrients such as calcium, iron, and zinc should be given more attention to prevent nutrient deficiencies and subsequent health consequences.
PubMed, Sep 1, 2008
Aim: The purpose of this study was to investigate the effect of hypohydration (HH) on the lactate... more Aim: The purpose of this study was to investigate the effect of hypohydration (HH) on the lactate threshold (LT) in a hot and humid environment. Methods: Ten apparently healthy males (age 25+/-3 yrs; height 1.8+/-0.04 m; mass 78+/-12 kg; VO2peak 3.7+/-0.4 L/min) underwent four randomly assigned maximal treadmill tests. Two trials were at room temperature (22+/-1 degrees C; RH = 50%) under two different hydration conditions: euhydrated (EH-RM) and hypohydrated (HH-RM), and two trials were performed in a warm chamber (37+/-0.5 degrees C; RH = 70%) under two different hydration conditions: euhydrated (EH-HT) and hypohydrated (HH-HT). The desired HH level (2-4%) was accomplished in the 24+ hours before testing by fluid restriction. Mean HH was 2.6+/-1.0% body weight. Capillary blood samples were collected at the end of each stage and analyzed for lactic acid (LA). LA concentrations were plotted for each exercise stage, and the LT was determined by visual inspection as the highest exercise stage at which blood LA concentration began to increase above each individual's resting levels. LT and body temperature were analyzed with a two-way repeated measures ANOVA (P < 0.05). Results: During the trials in the warm chamber, the LT occurred at a significantly earlier stage compared to the thermoneutral environment (4.4+/-0.09 vs 5.8+/-0.10) and with a significantly lower oxygen consumption (2.38+/-0.09 L.min(-1) vs 2.86+/-0.13 L.min(-1)). Body temperature at the LT was significantly higher in the heat trials compared to room temperature (38.7+/-0.12 degrees C vs 37.6+/-0.14 degrees C). LT determination was not significantly altered by hydration. Conclusion: These results suggest that during progressive incremental maximal treadmill exercise, moderate HH does not affect the LT, whereas exercise in a hot and humid environment induces a downward shift in the LT. The elevated body temperature during the heat trials suggests that body temperature may affect running performance associated with the LT.
ЦЕННОСТНАЯ ОРИЕНТАЦИЯ МЛАДШИХ ШКОЛЬНИКОВ В ПОТРЕБНОСТЯХ К ФИЗКУЛЬТУРНО-СПОРТИВНОЙ ДЕЯТЕЛЬНОСТИ Та... more ЦЕННОСТНАЯ ОРИЕНТАЦИЯ МЛАДШИХ ШКОЛЬНИКОВ В ПОТРЕБНОСТЯХ К ФИЗКУЛЬТУРНО-СПОРТИВНОЙ ДЕЯТЕЛЬНОСТИ Татьяна Евгеньевна Виленская, кандидат биологических наук, ФГОУ ВПО «Кубанский государственный университет физической культуры, спорта и туризма» (КГУФКСТ), г. Краснодар Аннотация В статье представлены данные об экспериментальной программе по физическому воспитанию детей младшего школьного возраста. Ключевые слова: физическое воспитание, мотивационно-потребностная сфера, ценностная переориентация, учащиеся младших классов.
International journal of sports and exercise medicine, Mar 30, 2019
Background: Although protein consumption has been documented to influence body composition in hum... more Background: Although protein consumption has been documented to influence body composition in humans, the effect on fat-free mass and fat mass, as influenced by the timing, frequency, and state of energy balance during the day when protein is consumed has not been fully investigated. Aim: The purpose of this cross-sectional study was to assess whether the amount and frequency of dietary protein intake, and the state of energy balance when consumed, are associated with body composition of collegiate women's soccer athletes. Methods: Data from nutrition assessments conducted during off-season training were collected in 20 healthy Division 1 female soccer athletes, aged 18-21 years. At visit 1, participants were instructed on how to keep a three-day food and exercise record with hourly measures. At visit 2, food and exercise logs were reviewed, nutrition history questionnaires were completed, and the following measurements were taken: height, weight, and body composition using multi-current segmental Bioelectrical Impedance Analysis (BIA). Hourly protein intake and hourly Energy Balance (EB), a measure of whether energy intake is dynamically matching requirements (energy expenditure), were computed using nutrition analysis software. Results: Spearman correlations were used to assess the relationships between dietary protein intake, state of energy balance when consumed, and body composition. It was found that consuming protein in moderate amounts of between 15 to 30 g, with sufficient frequency to supply predicted daily need and while in a state of energy balance >-300 kcal, is significantly associated with lower Fat Mass Adjusted for total body weight (FM-Adj) (r s =-0.546; p = 0.013) and greater Fat-Free Mass Adjusted for total body weight (FFM-Adj) (r s = 0.546; p = 0.013). Conclusion: These data suggest that collegiate female soccer players should consume their individual recommended daily amount of protein in ~15-30 g servings while in a reasonable state of energy balance (>-300 kcal) to achieve lower fat mass and higher fat-free mass.
Blackwell Science Ltd eBooks, Mar 17, 2008
ABSTRACT
International journal of sports and exercise medicine, Dec 31, 2018
Tienda online donde Comprar Advanced Sports Nutrition al precio 16,06 € de Dan Benardot, tienda d... more Tienda online donde Comprar Advanced Sports Nutrition al precio 16,06 € de Dan Benardot, tienda de Libros de Medicina, Libros de Medicina del Deporte - Medicina Deportiva
Nutrients
There is increasing evidence that dietary protein intake with leucine and vitamin D is an importa... more There is increasing evidence that dietary protein intake with leucine and vitamin D is an important factor in muscle protein synthesis. This study investigated the combined effects of consuming whey protein and vitamin D3 in the evening before bedtime or in the morning after sleeping on muscle mass and strength. Healthy, untrained males (N = 42; Age = 18–24 year) were randomly assigned into three groups: before bedtime, after sleeping, and control. Subjects underwent a 6-week resistance training program in combination with supplements that provided 25 g whey protein and 4000 IU vitamin D3 for the before bedtime and after sleeping groups and a 5 g maltodextrin placebo for the control group. A significant increase in serum vitamin D was observed in both before bedtime and after sleeping groups. All groups experienced a significant gain in leg press. However, the control group did not experience significant improvements in muscle mass and associated blood hormones that were experienced...
Journal of the International Society of Sports Nutrition, 2020
Objective Previous investigations suggest that appropriate nutritional interventions may reduce d... more Objective Previous investigations suggest that appropriate nutritional interventions may reduce delayed onset muscle soreness (DOMS). This study examined the effect of D-ribose supplementation on DOMS induced by plyometric exercise. Methods For the purpose of inducing DOMS, 21 untrained male college students performed a lower-limb plyometric exercise session that involved 7 sets of 20 consecutive frog hops with 90-s of rest between each set. Muscle soreness was measured with a visual analogue scale 1-h before, 24-h after, and 48-h after exercise. Subjects were then randomly placed into the D-ribose group (DRIB, n = 11) and the placebo group (PLAC, n = 10) to assure equivalent BMI and muscle soreness. After a 14-d washout/recovery period, subjects performed the same exercise session, with DRIB ingesting a 200 ml solution containing 15 g D-ribose 1-h before, 1-h, 12-h, 24-h, and 36-h after exercise, and PLAC ingesting a calorically equivalent placebo of the same volume and taste conta...
Medicine & Science in Sports & Exercise, 2020
Journal of the International Society of Sports Nutrition, 2020
Background Low energy availability (LEA) is a medical condition observed in athletes, with a high... more Background Low energy availability (LEA) is a medical condition observed in athletes, with a higher prevalence in aesthetic sports. For the first time, this study evaluated the relative prevalence of LEA in female elite athletes (ELA) and recreational athletes (REA) in aesthetic sports in China. Methods Female athletes from 6 sports (trampolining, rhythmic gymnastics, aerobics, dance sport, cheerleading and dance) were recruited, including ELA (n = 52; age = 20 ± 3) on Chinese national teams and REA (n = 114; Age = 20 ± 2) from Beijing Sport University. Participants completed 2 online questionnaires to assess LEA and eating disorder risk. These included the Low Energy Availability in Females Questionnaire (LEAF-Q), which provided information on injury history, gastrointestinal function and menstrual history, and the Eating Disorder Inventory-3 Referral Form (EDI-3 RF). For a sub-group of elite athletes (n = 14), body composition, bone mineral density, and blood serum were also quant...
Scandinavian Journal of Medicine & Science in Sports, 2018
We aimed to estimate and compare within-day energy balance (WDEB) in athletes with eumenorrhea an... more We aimed to estimate and compare within-day energy balance (WDEB) in athletes with eumenorrhea and menstrual dysfunction (MD) with similar 24-hour energy availability/energy balance (EA/EB). Furthermore, to investigate whether within-day energy deficiency is associated with resting metabolic rate (RMR), body-composition, S-cortisol, estradiol, T 3 , and fasting blood glucose. We reanalyzed 7-day dietary intake and energy expenditure data in 25 elite endurance athletes with eumenorrhea (n=10) and MD (n=15) from a group of 45 subjects where those with disordered eating behaviors (n=11), MD not related to low EA (n=5), and low dietary record validity (n=4) had been excluded. Besides gynecological examination and disordered eatingevaluation, the protocol included RMR-measurement; assessment of body-composition by dualenergy X-ray absorptiometry, blood plasma analysis, and calculation of WDEB in 1-hour intervals. Subjects with MD spent more hours in a catabolic state compared to eumenorrheic
Journal of Science in Sport and Exercise, 2019
Purpose We sought to describe and examine the interrelationships between energy intake, body comp... more Purpose We sought to describe and examine the interrelationships between energy intake, body composition, and estimated energy balance. Methods Using self-reported hourly food intake and formula-based energy expenditure (EE) protocols, 19 female professional cheerleaders (mean age 25.4 years) were assessed to obtain energy balance (EB) for a typical training day. Energy intake (EI) was predicted using the USDA Food Composition Database SR27, and EE was predicted using the Harris-Benedict equation plus a MET-based relative intensity activity scale. Body composition was predicted using a multi-current, 8-mode segmental bioelectrical impedance analysis system. Hourly and daily EB was calculated from EI and EE data. Results Subjects reported a 24 h EI significantly below (P < 0.001) the unadjusted predicted energy requirement (1482 kcal vs. 2199 kcal, respectively), resulting in an average negative net EB of − 720 kcal. Carbohydrate intake was significantly below the minimum recommended level (3.1 g/kg vs. 6 g/kg, P < 0.001) while protein and fat intakes met the recommended levels. Higher fat intake (g/kg) was significantly associated with a higher EI kcal/kg (r = 0.726; P < 0.001), which was significantly associated (r = − 0.55; P = 0.01) with a lower body fat percent (BF%). Using the median of BF% (20.9) as the cut point, participants with fewer hours in a negative EB had lower BF% (P = 0.043) and those with lower BF% spent more time in an EB of ± 300 kcal (P = 0.013). Conclusions These athletes reported low energy intakes that resulted in large EB deficits and/or more hours in a negative EB, which could be counterproductive for achieving a lean body composition overtime.
Part I: Key Factors for Optimal Performance Chapter 1. Dietary Science and Athletic Excellence Ch... more Part I: Key Factors for Optimal Performance Chapter 1. Dietary Science and Athletic Excellence Chapter 2. Digestion and Absorption Chapter 3. Optimal Distribution of Energy Nutrients Chapter 4. Vitamins and Minerals Chapter 5. Micronutrients and Oxygen Delivery Chapter 6. Fluids and Electrolytes Chapter 7. Ergogenic Aids Chapter 8. Fuel Utilization Inhibitors Chapter 9. Energy Intake-Expenditure Balance Chapter 10. Travel Chapter 11. High Altitude Chapter 12. Gender and Age Chapter 13. Body Composition and Weight Part II: Energy System-Specific Nutritional Strategies Chapter 14. Phosphagen System for Highly Intense Bursts Chapter 15. Anaerobic Metabolism for Power Chapter 16. Aerobic Metabolism for Endurance Part III: Sport-Specific Nutritional Plans Chapter 17. Power Sports Chapter 18. Endurance Sports Chapter 19. Combination Sports.
Nutrients, 2021
Abstract: Periodized carbohydrate availability can enhance exercise capacity, but the effects of ... more Abstract: Periodized carbohydrate availability can enhance exercise capacity, but the effects of short- term fat adaptation carbohydrate restoration (FACR) diets on metabolic responses and exercise performance in endurance athletes have not been conclusively determined. This study aimed to investigate the effect of a FACR diet on measures of resting metabolism, exercise metabolism, and exercise performance. Well-trained male runners (n = 8) completed a FACR dietary intervention (five days’ carbohydrate < 20% and fat > 60% energy, plus one-day carbohydrate ≥ 70% energy), and a control high-carbohydrate (HCHO) diet for six days (carbohydrate > 60% energy; fat < 20% energy) in a randomized crossover design. Pre- and post-intervention metabolic measures included resting metabolic rate (RMR), respiratory quotient (RQ), maximum fat oxidation rate during exercise (MFO), and maximum fat oxidation intensity (FATmax). Measures of exercise performance included maximal oxygen uptake (VO2max), running economy (RE), and 5 km running time trial (5 km-TT). In FACR compared with HCHO, there were significant improvements in FATmax (p = 0.006) and RE (p = 0.048). There were no significant differences (p > 0.05) between FACR and HCHO in RMR, RQ, VO2max, or 5 km-TT. Findings suggest that a short-term (six days) FACR diet may facilitate increased fat oxidation and submaximal exercise economy but does not improve 5 km-TT performance.
Keywords: periodized nutrition; high carbohydrate; high fat diet; glycogen restoration
Nutrients, 2022
Abstract: There is increasing evidence that dietary protein intake with leucine and vitamin D is ... more Abstract: There is increasing evidence that dietary protein intake with leucine and vitamin D is an important factor in muscle protein synthesis. This study investigated the combined effects of con- suming whey protein and vitamin D3 in the evening before bedtime or in the morning after sleeping on muscle mass and strength. Healthy, untrained males (N = 42; Age = 18–24 year) were randomly assigned into three groups: before bedtime, after sleeping, and control. Subjects underwent a 6-week resistance training program in combination with supplements that provided 25 g whey protein and 4000 IU vitamin D3 for the before bedtime and after sleeping groups and a 5 g maltodextrin placebo for the control group. A significant increase in serum vitamin D was observed in both before bedtime and after sleeping groups. All groups experienced a significant gain in leg press. However, the control group did not experience significant improvements in muscle mass and associated blood hormones that were experienced by the before bedtime and after sleeping groups. No significant differences in assessed values were observed between the before bedtime and after sleeping groups. These findings suggest that the combination of whey protein and vitamin D supplements provided either before or after sleep resulted in beneficial increases in muscle mass in young males undergoing resistance training that exceeded the changes observed without these supplements.
Keywords: protein distribution; whey protein; vitamin D; muscle mass; muscle strength
HSOA journal of physical medicine, rehabilitation & disabilities, May 16, 2024
Occupational Health and Industrial Medicine, 1999
The nutrient intakes and dietary practices of elite, U.S. national team, artistic female gymnasts... more The nutrient intakes and dietary practices of elite, U.S. national team, artistic female gymnasts (n = 33) were evaluated using 3-day food records. The gymnasts' reported energy intake was 34.4 kcal/kg (total 1,678 kcal/day), which was 20% below the estimated energy requirement. The contributions of protein, fat, and carbohydrate to total energy intake were 17%, 18%, and 66%, respectively. All reported vitamin intakes, except vitamin E, were above the RDA. The reported mineral intakes, especially calcium, zinc, and magnesium, were less than 100% of the RDA. The overall nutrient densities of the subjects' diets were higher than expected. Eighty-two percent of the gymnasts reported taking nonprescription vitamin and mineral supplements, and 10% reported taking prescription vitamin and mineral supplements. Forty-eight percent of the gymnasts reported being on a self-prescribed diet. Compared to NHANES III, the reported nutrient intake of these gymnasts was different from that of the average U.S. adolescent female. In summary, certain key nutrients such as calcium, iron, and zinc should be given more attention to prevent nutrient deficiencies and subsequent health consequences.
PubMed, Sep 1, 2008
Aim: The purpose of this study was to investigate the effect of hypohydration (HH) on the lactate... more Aim: The purpose of this study was to investigate the effect of hypohydration (HH) on the lactate threshold (LT) in a hot and humid environment. Methods: Ten apparently healthy males (age 25+/-3 yrs; height 1.8+/-0.04 m; mass 78+/-12 kg; VO2peak 3.7+/-0.4 L/min) underwent four randomly assigned maximal treadmill tests. Two trials were at room temperature (22+/-1 degrees C; RH = 50%) under two different hydration conditions: euhydrated (EH-RM) and hypohydrated (HH-RM), and two trials were performed in a warm chamber (37+/-0.5 degrees C; RH = 70%) under two different hydration conditions: euhydrated (EH-HT) and hypohydrated (HH-HT). The desired HH level (2-4%) was accomplished in the 24+ hours before testing by fluid restriction. Mean HH was 2.6+/-1.0% body weight. Capillary blood samples were collected at the end of each stage and analyzed for lactic acid (LA). LA concentrations were plotted for each exercise stage, and the LT was determined by visual inspection as the highest exercise stage at which blood LA concentration began to increase above each individual's resting levels. LT and body temperature were analyzed with a two-way repeated measures ANOVA (P < 0.05). Results: During the trials in the warm chamber, the LT occurred at a significantly earlier stage compared to the thermoneutral environment (4.4+/-0.09 vs 5.8+/-0.10) and with a significantly lower oxygen consumption (2.38+/-0.09 L.min(-1) vs 2.86+/-0.13 L.min(-1)). Body temperature at the LT was significantly higher in the heat trials compared to room temperature (38.7+/-0.12 degrees C vs 37.6+/-0.14 degrees C). LT determination was not significantly altered by hydration. Conclusion: These results suggest that during progressive incremental maximal treadmill exercise, moderate HH does not affect the LT, whereas exercise in a hot and humid environment induces a downward shift in the LT. The elevated body temperature during the heat trials suggests that body temperature may affect running performance associated with the LT.
ЦЕННОСТНАЯ ОРИЕНТАЦИЯ МЛАДШИХ ШКОЛЬНИКОВ В ПОТРЕБНОСТЯХ К ФИЗКУЛЬТУРНО-СПОРТИВНОЙ ДЕЯТЕЛЬНОСТИ Та... more ЦЕННОСТНАЯ ОРИЕНТАЦИЯ МЛАДШИХ ШКОЛЬНИКОВ В ПОТРЕБНОСТЯХ К ФИЗКУЛЬТУРНО-СПОРТИВНОЙ ДЕЯТЕЛЬНОСТИ Татьяна Евгеньевна Виленская, кандидат биологических наук, ФГОУ ВПО «Кубанский государственный университет физической культуры, спорта и туризма» (КГУФКСТ), г. Краснодар Аннотация В статье представлены данные об экспериментальной программе по физическому воспитанию детей младшего школьного возраста. Ключевые слова: физическое воспитание, мотивационно-потребностная сфера, ценностная переориентация, учащиеся младших классов.
International journal of sports and exercise medicine, Mar 30, 2019
Background: Although protein consumption has been documented to influence body composition in hum... more Background: Although protein consumption has been documented to influence body composition in humans, the effect on fat-free mass and fat mass, as influenced by the timing, frequency, and state of energy balance during the day when protein is consumed has not been fully investigated. Aim: The purpose of this cross-sectional study was to assess whether the amount and frequency of dietary protein intake, and the state of energy balance when consumed, are associated with body composition of collegiate women's soccer athletes. Methods: Data from nutrition assessments conducted during off-season training were collected in 20 healthy Division 1 female soccer athletes, aged 18-21 years. At visit 1, participants were instructed on how to keep a three-day food and exercise record with hourly measures. At visit 2, food and exercise logs were reviewed, nutrition history questionnaires were completed, and the following measurements were taken: height, weight, and body composition using multi-current segmental Bioelectrical Impedance Analysis (BIA). Hourly protein intake and hourly Energy Balance (EB), a measure of whether energy intake is dynamically matching requirements (energy expenditure), were computed using nutrition analysis software. Results: Spearman correlations were used to assess the relationships between dietary protein intake, state of energy balance when consumed, and body composition. It was found that consuming protein in moderate amounts of between 15 to 30 g, with sufficient frequency to supply predicted daily need and while in a state of energy balance >-300 kcal, is significantly associated with lower Fat Mass Adjusted for total body weight (FM-Adj) (r s =-0.546; p = 0.013) and greater Fat-Free Mass Adjusted for total body weight (FFM-Adj) (r s = 0.546; p = 0.013). Conclusion: These data suggest that collegiate female soccer players should consume their individual recommended daily amount of protein in ~15-30 g servings while in a reasonable state of energy balance (>-300 kcal) to achieve lower fat mass and higher fat-free mass.
Blackwell Science Ltd eBooks, Mar 17, 2008
ABSTRACT
International journal of sports and exercise medicine, Dec 31, 2018
Tienda online donde Comprar Advanced Sports Nutrition al precio 16,06 € de Dan Benardot, tienda d... more Tienda online donde Comprar Advanced Sports Nutrition al precio 16,06 € de Dan Benardot, tienda de Libros de Medicina, Libros de Medicina del Deporte - Medicina Deportiva
Nutrients
There is increasing evidence that dietary protein intake with leucine and vitamin D is an importa... more There is increasing evidence that dietary protein intake with leucine and vitamin D is an important factor in muscle protein synthesis. This study investigated the combined effects of consuming whey protein and vitamin D3 in the evening before bedtime or in the morning after sleeping on muscle mass and strength. Healthy, untrained males (N = 42; Age = 18–24 year) were randomly assigned into three groups: before bedtime, after sleeping, and control. Subjects underwent a 6-week resistance training program in combination with supplements that provided 25 g whey protein and 4000 IU vitamin D3 for the before bedtime and after sleeping groups and a 5 g maltodextrin placebo for the control group. A significant increase in serum vitamin D was observed in both before bedtime and after sleeping groups. All groups experienced a significant gain in leg press. However, the control group did not experience significant improvements in muscle mass and associated blood hormones that were experienced...
Journal of the International Society of Sports Nutrition, 2020
Objective Previous investigations suggest that appropriate nutritional interventions may reduce d... more Objective Previous investigations suggest that appropriate nutritional interventions may reduce delayed onset muscle soreness (DOMS). This study examined the effect of D-ribose supplementation on DOMS induced by plyometric exercise. Methods For the purpose of inducing DOMS, 21 untrained male college students performed a lower-limb plyometric exercise session that involved 7 sets of 20 consecutive frog hops with 90-s of rest between each set. Muscle soreness was measured with a visual analogue scale 1-h before, 24-h after, and 48-h after exercise. Subjects were then randomly placed into the D-ribose group (DRIB, n = 11) and the placebo group (PLAC, n = 10) to assure equivalent BMI and muscle soreness. After a 14-d washout/recovery period, subjects performed the same exercise session, with DRIB ingesting a 200 ml solution containing 15 g D-ribose 1-h before, 1-h, 12-h, 24-h, and 36-h after exercise, and PLAC ingesting a calorically equivalent placebo of the same volume and taste conta...
Medicine & Science in Sports & Exercise, 2020
Journal of the International Society of Sports Nutrition, 2020
Background Low energy availability (LEA) is a medical condition observed in athletes, with a high... more Background Low energy availability (LEA) is a medical condition observed in athletes, with a higher prevalence in aesthetic sports. For the first time, this study evaluated the relative prevalence of LEA in female elite athletes (ELA) and recreational athletes (REA) in aesthetic sports in China. Methods Female athletes from 6 sports (trampolining, rhythmic gymnastics, aerobics, dance sport, cheerleading and dance) were recruited, including ELA (n = 52; age = 20 ± 3) on Chinese national teams and REA (n = 114; Age = 20 ± 2) from Beijing Sport University. Participants completed 2 online questionnaires to assess LEA and eating disorder risk. These included the Low Energy Availability in Females Questionnaire (LEAF-Q), which provided information on injury history, gastrointestinal function and menstrual history, and the Eating Disorder Inventory-3 Referral Form (EDI-3 RF). For a sub-group of elite athletes (n = 14), body composition, bone mineral density, and blood serum were also quant...
Scandinavian Journal of Medicine & Science in Sports, 2018
We aimed to estimate and compare within-day energy balance (WDEB) in athletes with eumenorrhea an... more We aimed to estimate and compare within-day energy balance (WDEB) in athletes with eumenorrhea and menstrual dysfunction (MD) with similar 24-hour energy availability/energy balance (EA/EB). Furthermore, to investigate whether within-day energy deficiency is associated with resting metabolic rate (RMR), body-composition, S-cortisol, estradiol, T 3 , and fasting blood glucose. We reanalyzed 7-day dietary intake and energy expenditure data in 25 elite endurance athletes with eumenorrhea (n=10) and MD (n=15) from a group of 45 subjects where those with disordered eating behaviors (n=11), MD not related to low EA (n=5), and low dietary record validity (n=4) had been excluded. Besides gynecological examination and disordered eatingevaluation, the protocol included RMR-measurement; assessment of body-composition by dualenergy X-ray absorptiometry, blood plasma analysis, and calculation of WDEB in 1-hour intervals. Subjects with MD spent more hours in a catabolic state compared to eumenorrheic
Journal of Science in Sport and Exercise, 2019
Purpose We sought to describe and examine the interrelationships between energy intake, body comp... more Purpose We sought to describe and examine the interrelationships between energy intake, body composition, and estimated energy balance. Methods Using self-reported hourly food intake and formula-based energy expenditure (EE) protocols, 19 female professional cheerleaders (mean age 25.4 years) were assessed to obtain energy balance (EB) for a typical training day. Energy intake (EI) was predicted using the USDA Food Composition Database SR27, and EE was predicted using the Harris-Benedict equation plus a MET-based relative intensity activity scale. Body composition was predicted using a multi-current, 8-mode segmental bioelectrical impedance analysis system. Hourly and daily EB was calculated from EI and EE data. Results Subjects reported a 24 h EI significantly below (P < 0.001) the unadjusted predicted energy requirement (1482 kcal vs. 2199 kcal, respectively), resulting in an average negative net EB of − 720 kcal. Carbohydrate intake was significantly below the minimum recommended level (3.1 g/kg vs. 6 g/kg, P < 0.001) while protein and fat intakes met the recommended levels. Higher fat intake (g/kg) was significantly associated with a higher EI kcal/kg (r = 0.726; P < 0.001), which was significantly associated (r = − 0.55; P = 0.01) with a lower body fat percent (BF%). Using the median of BF% (20.9) as the cut point, participants with fewer hours in a negative EB had lower BF% (P = 0.043) and those with lower BF% spent more time in an EB of ± 300 kcal (P = 0.013). Conclusions These athletes reported low energy intakes that resulted in large EB deficits and/or more hours in a negative EB, which could be counterproductive for achieving a lean body composition overtime.
Part I: Key Factors for Optimal Performance Chapter 1. Dietary Science and Athletic Excellence Ch... more Part I: Key Factors for Optimal Performance Chapter 1. Dietary Science and Athletic Excellence Chapter 2. Digestion and Absorption Chapter 3. Optimal Distribution of Energy Nutrients Chapter 4. Vitamins and Minerals Chapter 5. Micronutrients and Oxygen Delivery Chapter 6. Fluids and Electrolytes Chapter 7. Ergogenic Aids Chapter 8. Fuel Utilization Inhibitors Chapter 9. Energy Intake-Expenditure Balance Chapter 10. Travel Chapter 11. High Altitude Chapter 12. Gender and Age Chapter 13. Body Composition and Weight Part II: Energy System-Specific Nutritional Strategies Chapter 14. Phosphagen System for Highly Intense Bursts Chapter 15. Anaerobic Metabolism for Power Chapter 16. Aerobic Metabolism for Endurance Part III: Sport-Specific Nutritional Plans Chapter 17. Power Sports Chapter 18. Endurance Sports Chapter 19. Combination Sports.
Nutrients, 2021
Abstract: Periodized carbohydrate availability can enhance exercise capacity, but the effects of ... more Abstract: Periodized carbohydrate availability can enhance exercise capacity, but the effects of short- term fat adaptation carbohydrate restoration (FACR) diets on metabolic responses and exercise performance in endurance athletes have not been conclusively determined. This study aimed to investigate the effect of a FACR diet on measures of resting metabolism, exercise metabolism, and exercise performance. Well-trained male runners (n = 8) completed a FACR dietary intervention (five days’ carbohydrate < 20% and fat > 60% energy, plus one-day carbohydrate ≥ 70% energy), and a control high-carbohydrate (HCHO) diet for six days (carbohydrate > 60% energy; fat < 20% energy) in a randomized crossover design. Pre- and post-intervention metabolic measures included resting metabolic rate (RMR), respiratory quotient (RQ), maximum fat oxidation rate during exercise (MFO), and maximum fat oxidation intensity (FATmax). Measures of exercise performance included maximal oxygen uptake (VO2max), running economy (RE), and 5 km running time trial (5 km-TT). In FACR compared with HCHO, there were significant improvements in FATmax (p = 0.006) and RE (p = 0.048). There were no significant differences (p > 0.05) between FACR and HCHO in RMR, RQ, VO2max, or 5 km-TT. Findings suggest that a short-term (six days) FACR diet may facilitate increased fat oxidation and submaximal exercise economy but does not improve 5 km-TT performance.
Keywords: periodized nutrition; high carbohydrate; high fat diet; glycogen restoration
Nutrients, 2022
Abstract: There is increasing evidence that dietary protein intake with leucine and vitamin D is ... more Abstract: There is increasing evidence that dietary protein intake with leucine and vitamin D is an important factor in muscle protein synthesis. This study investigated the combined effects of con- suming whey protein and vitamin D3 in the evening before bedtime or in the morning after sleeping on muscle mass and strength. Healthy, untrained males (N = 42; Age = 18–24 year) were randomly assigned into three groups: before bedtime, after sleeping, and control. Subjects underwent a 6-week resistance training program in combination with supplements that provided 25 g whey protein and 4000 IU vitamin D3 for the before bedtime and after sleeping groups and a 5 g maltodextrin placebo for the control group. A significant increase in serum vitamin D was observed in both before bedtime and after sleeping groups. All groups experienced a significant gain in leg press. However, the control group did not experience significant improvements in muscle mass and associated blood hormones that were experienced by the before bedtime and after sleeping groups. No significant differences in assessed values were observed between the before bedtime and after sleeping groups. These findings suggest that the combination of whey protein and vitamin D supplements provided either before or after sleep resulted in beneficial increases in muscle mass in young males undergoing resistance training that exceeded the changes observed without these supplements.
Keywords: protein distribution; whey protein; vitamin D; muscle mass; muscle strength