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Rehrer NJ, Hellemans IJ, Rolleston AK, Rush E, Miller BF. Energy intake and expenditure during a 6-day cycling stage race. Scand J Med Sci Sports 2009; 20:609-18. [PMID: 19602187 DOI: 10.1111/j.1600-0838.2009.00974.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Energy intake (EI) and energy expenditure (EE) are relatively easy to measure accurately over short periods in a laboratory setting, but less so during a multi-day competition. Our goal was to measure EI and EE as accurately as possible during a 6-day, 10-stage cycling race. We prepared all meals and supplements, assessed EI (weighed diet-records) and macrontrient intake, total EE (doubly labelled water), resting metabolic rate (respiratory gas exchange), exercise EE (power meters), and body mass. Body composition was measured several days before and after racing (dual x-ray absorptiometry). Body mass remained stable over the course of the race. The mean EI (27.3+/-3.8 MJ/day) nearly matched EE (27.4+/-2.0 MJ/day). The majority (62%) of EE was exercise EE. Macronutrient intake was within or exceeded the recommendations. Lean body mass increased and fat mass decreased in most of our participants. Our study indicates that EI can match high EE with adequate macronutrient intake during multi-day cycle racing and may be facilitated by appropriate foods being available at appropriate times. This optimization of nutritional provision supports positive changes in body composition.
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Affiliation(s)
- N J Rehrer
- School of Physical Education, University of Otago, Dunedin, New Zealand.
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Manore MM, Kam LC, Loucks AB. The female athlete triad: components, nutrition issues, and health consequences. J Sports Sci 2009; 25 Suppl 1:S61-71. [PMID: 18049984 DOI: 10.1080/02640410701607320] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This paper, which was part of the International Association of Athletics Federations (IAAF) 2007 Nutritional Consensus Conference, briefly reviews the components of the female athlete triad (Triad): energy availability, menstrual status, and bone health. Each component of the Triad spans a continuum from health to disease, and female athletes can have symptoms related to each component of the Triad to different degrees. Low energy availability is the primary factor that impairs menstrual dysfunction and bone health in the Triad. We discuss nutritional issues associated with the Triad, focusing on intakes of macronutrients needed for good health, and stress fractures, the most common injury associated with the Triad. Finally, we briefly discuss screening and treatment for the Triad and the occurrence of the Triad in men.
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Affiliation(s)
- Melinda M Manore
- Department of Nutrition and Exercise Sciences, Oregon State University, Milam Hall 103, Corvallis, OR, USA.
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Modificações dietéticas, reposição hídrica, suplementos alimentares e drogas: comprovação de ação ergogênica e potenciais riscos para a saúde. REV BRAS MED ESPORTE 2009. [DOI: 10.1590/s1517-86922009000400001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Schröder S, Fischer A, Vock C, Böhme M, Schmelzer C, Döpner M, Hülsmann O, Döring F. Nutrition concepts for elite distance runners based on macronutrient and energy expenditure. J Athl Train 2009; 43:489-504. [PMID: 18833312 DOI: 10.4085/1062-6050-43.5.489] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Elite distance runners (EDR) must optimize their nutrition to maintain their demanding training schedules. OBJECTIVE To develop a nutrition concept for EDR based on energy and macronutrient expenditures. DESIGN This theoretical study provides calculations for macronutrient and energy expenditures of EDR. Anthropometric and metabolic characteristics of EDR were assumed based on average real EDR. SETTING University of Kiel. PATIENTS OR OTHER PARTICIPANTS Three prototypic types of male EDR described in the literature as type I (TI; body mass = 72 kg, respiratory quotient = 0.9 at rest, fast-twitch muscle fibers = 60% to 70%), type II (TII; body mass = 67 kg, respiratory quotient = 0.82 at rest, fast-twitch muscle fibers = 50%), and type III (TIII; body mass = 60 kg, respiratory quotient = 0.75 at rest, fast-twitch muscle fibers = 30% to 40%). MAIN OUTCOME MEASURE(S) We calculated the macronutrient and energy expenditures of the 3 types of EDR according to body mass, respiratory quotient, and percentage of fast-twitch muscle fibers. RESULTS We found that the average energy expenditure was 3750 kcal . d(-1) for TI runners, 3463 kcal . d(-1) for TII runners, and 3079 kcal . d(-1) for TIII runners. The carbohydrate (CHO) expenditure reached an average value of 10.0 g . kg(-1) . d(-1) for TI runners, 8.0 g . kg(-1) . d(-1) for TII runners, and 4.7 g . kg(-1) . d(-1) for TIII runners. When the EDR accomplished running sessions at a pace >or=100% of maximum oxygen consumption, all types of runners had a CHO demand of about 10 g . kg(-1) . d(-1). The TI and TII runners need a CHO intake of 8 to 10 g . kg(-1) . d(-1). For the TIII runners, a CHO intake >6 g . kg(-1) . d(-1) is necessary during anaerobic training sessions. CONCLUSIONS Nutrition concepts must be differentiated for EDR according to metabolic and anthropometric characteristics of the runners and their special training emphases.
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Maughan RJ, Bartagi Z, Dvorak J, Zerguini Y. Dietary intake and body composition of football players during the holy month of Ramadan. J Sports Sci 2008; 26 Suppl 3:S29-38. [DOI: 10.1080/02640410802409675] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Slivka D, Hailes W, Cuddy J, Ruby B. Caffeine and carbohydrate supplementation during exercise when in negative energy balance: effects on performance, metabolism, and salivary cortisol. Appl Physiol Nutr Metab 2008; 33:1079-85. [DOI: 10.1139/h08-093] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ingestion of carbohydrate (+CHO) and caffeine (+CAF) during exercise is a commonly used ergogenic practice. Investigations are typically conducted with subjects who are in a rested state after an overnight fast. However, this state of positive energy balance is not achieved during many work and exercise circumstances. The aim of this study was to evaluate the substrate use and performance effects of caffeine and carbohydrate consumed alone and in combination while participants were in negative energy balance. Male participants (n = 9; 23 ± 3 years; 74.1 ± 10.6 kg) completed 4 trials in random order: –CAF/–CHO, –CAF/+CHO, +CAF/–CHO, and +CAF/+CHO. Diet and exercise were prescribed for 2 days before each trial to ensure negative energy balance. For each trial, before and after 2 h of cycling at 50% of maximal watts, a saliva sample and a muscle biopsy (vastus lateralis) were obtained. A simulated 20 km time trial was then performed. The respiratory exchange ratio was higher (p < 0.05) in +CHO trials and lower (p < 0.05) in the +CAF/+CHO trial than in the –CAF/+CHO trial. Salivary cortisol response was higher (p < 0.05) in the +CAF/–CHO trial than in any of the other trials. Muscle glycogen and heart rates were similar in all trials. Performance in the 20 km time trial was better in the –CAF/+CHO trial than in the –CAF/–CHO trial (p < 0.05), but the +CAF/+CHO trial was no better than the +CAF/–CHO trial (p > 0.05), or any of the other trials. When co-ingested with carbohydrate, caffeine increased fat use and decreased nonmuscle glycogen carbohydrate use over carbohydrate alone when participants are in negative energy balance; however, caffeine had no effect on the 20 km cycling time trial performance.
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Affiliation(s)
- Dustin Slivka
- Montana Center for Work Physiology and Exercise Metabolism (WPEM), Department of Health and Human Performance, The University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - Walter Hailes
- Montana Center for Work Physiology and Exercise Metabolism (WPEM), Department of Health and Human Performance, The University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - John Cuddy
- Montana Center for Work Physiology and Exercise Metabolism (WPEM), Department of Health and Human Performance, The University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - Brent Ruby
- Montana Center for Work Physiology and Exercise Metabolism (WPEM), Department of Health and Human Performance, The University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
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Abstract
OBJECTIVE : To evaluate the evidence for dietary recommendations in older adult athletes. DESIGN : Interpretive review of the literature. RESULTS : Regarding resistance training, a protein intake of slightly more than 0.8 g/kg/d is required to optimize gains in muscle strength. The early provision of protein and carbohydrate following a weight training session can enhance resultant strength and fat-free mass gains. Supplementation with creatine monohydrate (approximately 5 g/d) can potentiate some of the gains in strength and fat free mass attained through resistance exercise training. Regarding endurance exercise training, there are no studies evaluating carbohydrate loading, during-event, or postexercise carbohydrate/nutritional replacement in older adults. CONCLUSIONS : The amount and timing of dietary protein is important to maximize strength and gains in fat-free mass during resistance exercise training. Creatine monohydrate supplementation can potentiate some of these gains during the first 4 to 6 months of training. Older adults should consume adequate carbohydrates during endurance training (6-8 g/kg/d) and may benefit from the provision of carbohydrate and protein in the early recovery phase following endurance exercise to maximize glycogen re-synthesis for a subsequent exercise bout. There is no scientific reason to assume that older athletes will respond differently to the pre- and during-race fluid and carbohydrate replacement strategies suggested for younger athletes. The consensus guidelines outlined by the American College of Sports Medicine should therefore be followed for all athletes, regardless of their age.
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108
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Kuczmarski K. Do Supplements Benefit Exercise? Am J Lifestyle Med 2008. [DOI: 10.1177/1559827608317769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
It is a known fact that exercise will have beneficial effects on one's health. Nutritional supplementation is on the rise, resulting in a billion-dollar industry. However, because these medications are not regulated by the Food and Drug Administration, it is difficult for the public to determine what is safe and effective. Health care providers have to be aware of this lack of knowledge and educate their patients on which supplements are beneficial and which may be harmful to their health.
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Arciero PJ, Gentile CL, Pressman R, Everett M, Ormsbee MJ, Martin J, Santamore J, Gorman L, Fehling PC, Vukovich MD, Nindl BC. Moderate protein intake improves total and regional body composition and insulin sensitivity in overweight adults. Metabolism 2008; 57:757-65. [PMID: 18502257 DOI: 10.1016/j.metabol.2008.01.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Accepted: 01/17/2008] [Indexed: 10/22/2022]
Abstract
A high protein intake (approximately 40% of energy intake) combined with aerobic and resistance exercise training is more closely associated with improved body composition and cardiovascular risk profile than a traditional protein intake (approximately 15% of intake) combined with moderate-intensity aerobic exercise. However, there is concern that such high-protein diets may adversely affect health. We therefore tested the hypothesis that moderate protein intake (approximately 25% of energy intake) would elicit similar benefits on body composition and metabolic profile as high protein intake. Twenty-four overweight/obese men and women (body mass index [BMI] = 32.2 +/- 3.4, percentage of body fat [%BF] = 37.3 +/- 8.0) were matched for BMI and %BF and randomly assigned to one of 3 groups for a 3-month nutrition/exercise training intervention: (1) high-protein diet (approximately 40% of energy intake) and combined high-intensity resistance and cardiovascular training (HPEx, n = 8, 5 female and 3 male), (2) moderate-protein diet (approximately 25% of energy intake) and combined high-intensity resistance and cardiovascular training (MPEx, n = 8, 5 female and 3 male), or (3) high-protein diet only (HPNx, n = 8, 5 female and 3 male). Total and regional body composition (dual-energy x-ray absorptiometry), insulin sensitivity (insulin sensitivity index to the oral glucose tolerance test), insulin-like growth factor-1 (IGF-1), IGF binding protein-1 (IGFBP-1), IGF binding protein-3 (IGFBP-3), and blood lipids were measured at baseline and after the intervention. All groups experienced significant (P < .05) and similar losses of body weight, BMI, and total and abdominal %BF, and similar improvements in insulin sensitivity (HPEx, 6.3 +/- 1.2 vs 9.5 +/- 0.98; MPEx, 6.2 +/- 1.4 vs 8.4 +/- 1.6; HPNx, 3.7 +/- 1.1 vs 7.0 +/- 1.1; insulin sensitivity index to the oral glucose tolerance test; P < .05) and leptin levels. Furthermore, the HPEx group demonstrated decreases in total cholesterol (TC) and triglycerides, and increases in IGF-1 and IGFBP-1. The MPEx group experienced decreases in TC, whereas the HPNx group had increases in high-density lipoprotein cholesterol, TC to high-density lipoprotein, IGF-1, and IGFBP-1. In conclusion, moderate protein intake elicits similar benefits in body composition and insulin sensitivity as a high-protein diet. These findings may have practical implications for individuals interested in diets containing elevated dietary protein.
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Affiliation(s)
- Paul J Arciero
- Department of Exercise Science, Skidmore College, Saratoga Springs, NY 12866, USA.
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110
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Tarnopolsky MA. Building muscle: nutrition to maximize bulk and strength adaptations to resistance exercise training. Eur J Sport Sci 2008. [DOI: 10.1080/17461390801919128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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113
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Vislocky LM, Gaine PC, Pikosky MA, Martin WF, Rodriguez NR. Gender impacts the post-exercise substrate and endocrine response in trained runners. J Int Soc Sports Nutr 2008; 5:7. [PMID: 18302755 PMCID: PMC2288589 DOI: 10.1186/1550-2783-5-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 02/26/2008] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Although several studies have investigated gender differences in the substrate and endocrine responses during and following endurance exercise, few have studied sex differences during a more prolonged recovery period post endurance exercise. The purpose of this study was to compare and characterize the endocrine and substrate profiles of trained male and female adult runners during the three-and-a-half hour recovery period from an endurance run. METHODS After consuming a euenergetic diet (1.8 g.kg-1.d-1 protein, 26% fat, 58% carbohydrates, 42.8 +/- 1.2 kcal/kg body weight) for 8 days, blood was collected from trained male (n = 6, 21 yrs, 70 kg, 180 cm, 9% body fat, VO(2peak) 78.0 +/- 3.4 mL.kg FFM-1.min-1) and female (n = 6, 23 y, 66 kg, 170 cm, 29% body fat, VO(2peak) 71.6 +/- 4.5 mL.kg FFM-1.min-1) endurance runners at rest and during recovery from a 75 min run at 70% VO(2peak). Circulating levels of glucose, lactate, free fatty acids (FFAs), insulin, cortisol, growth hormone (GH), and free insulin-like growth factor I (IGF-I) were measured. RESULTS During the recovery period, females experienced increases in glucose, lactate and insulin while no changes were noted in men (P < 0.05). Males experienced increases in GH and decreases in IGF-I levels respectively (P < 0.05) while no changes were observed in females. FFA levels increased during recovery from endurance exercise, but changes were not different between genders. CONCLUSION These data further document gender differences in substrate and endocrine changes during a prolonged recovery period following endurance exercise. Future studies are needed to evaluate the effect of differing diets and nutritional supplements on these gender-specific post-exercise substrate and endocrine differences.
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Affiliation(s)
- Lisa M Vislocky
- Department of Nutritional Sciences, 3624 Horsebarn Hill Road Ext. Unit 4017, University of Connecticut, Storrs, Connecticut, USA
| | - P Courtney Gaine
- Department of Nutritional Sciences, 3624 Horsebarn Hill Road Ext. Unit 4017, University of Connecticut, Storrs, Connecticut, USA
| | - Matthew A Pikosky
- Department of Nutritional Sciences, 3624 Horsebarn Hill Road Ext. Unit 4017, University of Connecticut, Storrs, Connecticut, USA
| | - William F Martin
- Department of Nutritional Sciences, 3624 Horsebarn Hill Road Ext. Unit 4017, University of Connecticut, Storrs, Connecticut, USA
| | - Nancy R Rodriguez
- Department of Nutritional Sciences, 3624 Horsebarn Hill Road Ext. Unit 4017, University of Connecticut, Storrs, Connecticut, USA
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Critical Importance of Controlling Energy Status to Understand the Effects of "Exercise" on Metabolism. Exerc Sport Sci Rev 2008; 36:2-4. [DOI: 10.1097/jes.0b013e31815e42c2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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115
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Panza VP, Coelho MSPH, Di Pietro PF, Assis MAAD, Vasconcelos FDAGD. Consumo alimentar de atletas: reflexões sobre recomendações nutricionais, hábitos alimentares e métodos para avaliação do gasto e consumo energéticos. REV NUTR 2007. [DOI: 10.1590/s1415-52732007000600010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
O objetivo do artigo foi efetuar revisão sobre o consumo alimentar de atletas, enfatizando recomendações nutricionais, adequações dietéticas, comportamento alimentar e limitações dos métodos na avaliação dietética e estimativa do gasto energético nesta população. Foram analisados 30 artigos, publicados no período de 1984-2004, selecionados em bases eletrônicas de dados. O critério de inclusão dos artigos foi a abordagem sobre aspectos nutricionais relacionados ao exercício, recomendações de energia e nutrientes, bem como consumo alimentar de atletas. As recomendações de energia, macronutrientes e hidratação para atletas já estão bem determinadas, porém, pouco se conhece sobre as necessidades de vitaminas e minerais. Contudo, existe um consenso de que as necessidades de micronutrientes para a maioria desses indivíduos podem ser atendidas por uma dieta variada e equilibrada. Por outro lado, estudos indicam que a inadequação de energia e nutrientes ainda predomina em vários grupos atléticos, revelando a necessidade da reeducação nutricional. Diversos fatores inerentes à modalidade esportiva, tais como os esquemas de treinamento e as exigências relativas à imagem corporal, podem influenciar os hábitos alimentares do atleta. Portanto, a compreensão das relações entre o padrão de alimentação de atletas e os diversos fatores relacionados ao esporte são aspectos fundamentais para o estabelecimento de orientações nutricionais. A ocorrência de erros sistemáticos em pesquisas com atletas que empregam métodos que utilizam o auto-relato, ressalta a importância do rigor metodológico na aplicação desses instrumentos.
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116
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Houtkooper L, Abbot JM, Nimmo M. Nutrition for throwers, jumpers, and combined events athletes. J Sports Sci 2007; 25 Suppl 1:S39-47. [DOI: 10.1080/02640410701607262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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118
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Nattiv A, Loucks AB, Manore MM, Sanborn CF, Sundgot-Borgen J, Warren MP. The Female Athlete Triad. Med Sci Sports Exerc 2007; 39:1867-82. [PMID: 17909417 DOI: 10.1249/mss.0b013e318149f111] [Citation(s) in RCA: 573] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The female athlete triad (Triad) refers to the interrelationships among energy availability, menstrual function, and bone mineral density, which may have clinical manifestations including eating disorders, functional hypothalamic amenorrhea, and osteoporosis. With proper nutrition, these same relationships promote robust health. Athletes are distributed along a spectrum between health and disease, and those at the pathological end may not exhibit all these clinical conditions simultaneously. Energy availability is defined as dietary energy intake minus exercise energy expenditure. Low energy availability appears to be the factor that impairs reproductive and skeletal health in the Triad, and it may be inadvertent, intentional, or psychopathological. Most effects appear to occur below an energy availability of 30 kcal.kg(-1) of fat-free mass per day. Restrictive eating behaviors practiced by girls and women in sports or physical activities that emphasize leanness are of special concern. For prevention and early intervention, education of athletes, parents, coaches, trainers, judges, and administrators is a priority. Athletes should be assessed for the Triad at the preparticipation physical and/or annual health screening exam, and whenever an athlete presents with any of the Triad's clinical conditions. Sport administrators should also consider rule changes to discourage unhealthy weight loss practices. A multidisciplinary treatment team should include a physician or other health-care professional, a registered dietitian, and, for athletes with eating disorders, a mental health practitioner. Additional valuable team members may include a certified athletic trainer, an exercise physiologist, and the athlete's coach, parents and other family members. The first aim of treatment for any Triad component is to increase energy availability by increasing energy intake and/or reducing exercise energy expenditure. Nutrition counseling and monitoring are sufficient interventions for many athletes, but eating disorders warrant psychotherapy. Athletes with eating disorders should be required to meet established criteria to continue exercising, and their training and competition may need to be modified. No pharmacological agent adequately restores bone loss or corrects metabolic abnormalities that impair health and performance in athletes with functional hypothalamic amenorrhea.
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119
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Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, Landis J, Lopez H, Antonio J. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr 2007; 4:8. [PMID: 17908291 PMCID: PMC2117006 DOI: 10.1186/1550-2783-4-8] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 09/26/2007] [Indexed: 12/02/2022] Open
Abstract
Position Statement The following seven points related to the intake of protein for healthy, exercising individuals constitute the position stand of the Society. They have been approved by the Research Committee of the Society. 1) Vast research supports the contention that individuals engaged in regular exercise training require more dietary protein than sedentary individuals. 2) Protein intakes of 1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training. 3) When part of a balanced, nutrient-dense diet, protein intakes at this level are not detrimental to kidney function or bone metabolism in healthy, active persons. 4) While it is possible for physically active individuals to obtain their daily protein requirements through a varied, regular diet, supplemental protein in various forms are a practical way of ensuring adequate and quality protein intake for athletes. 5) Different types and quality of protein can affect amino acid bioavailability following protein supplementation. The superiority of one protein type over another in terms of optimizing recovery and/or training adaptations remains to be convincingly demonstrated. 6) Appropriately timed protein intake is an important component of an overall exercise training program, essential for proper recovery, immune function, and the growth and maintenance of lean body mass. 7) Under certain circumstances, specific amino acid supplements, such as branched-chain amino acids (BCAA's), may improve exercise performance and recovery from exercise.
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Affiliation(s)
- Bill Campbell
- Exercise and Performance Nutrition Laboratory, Dept. of Physical Education and Exercise Science, University of South Florida, 4202 E. Fowler Avenue, PED 214, Tampa, FL 33620, USA
| | - Richard B Kreider
- Exercise and Sport Nutrition Laboratory, Dept. of Health, Human Performance, and Recreation, Baylor University, One Bear Place 97313, Waco, TX 76798-7313, USA
| | - Tim Ziegenfuss
- Ohio Research Group of Exercise Science & Sports Nutrition, Wadsworth Medical Center, 323 High St, STE 103A, Wadsworth, OH 44281, USA
| | - Paul La Bounty
- Exercise and Sport Nutrition Laboratory, Dept. of Health, Human Performance, and Recreation, Baylor University, One Bear Place 97313, Waco, TX 76798-7313, USA
| | - Mike Roberts
- Applied Biochemistry and Molecular Physiology Laboratory, Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Avenue, Norman, OK 73019, USA
| | - Darren Burke
- Exercise Science Laboratory, Dept. of Human Kinetics, St. Francis Xavier University, P.O. Box 5000 Antigonish, Nova Scotia, B2G 2W5, Canada
| | - Jamie Landis
- Department of Biology, Lakeland Community College, 7700 Clocktower Drive, Kirtland, Ohio 44094-5198, USA
| | - Hector Lopez
- Northwestern University Feinberg School of Medicine, Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, 345 East Superior Street, Chicago, IL 60611, USA
| | - Jose Antonio
- Department of Exercise Science and Health Promotion, Florida Atlantic University, 2912 College Avenue, Davie, FL 33314, USA
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Abstract
Prolonged endurance exercise stimulates whole-body protein turnover (synthesis and degradation) but it remains contentious whether this translates into an increased net protein oxidation or dietary requirement for protein. Skeletal muscle is the major energy consumer during exercise and the oxidation of branched-chain amino acids (BCAA) is increased several-fold, suggesting an increased requirement for fuel. Increased BCAA oxidation has been proposed to impair aerobic energy provision during prolonged exercise, but there is little evidence to support this theory. Endurance training blunts the acute exercise-induced increase in whole-body protein turnover and skeletal BCAA oxidation at a given work intensity. However, training also increases the maximal capacity for skeletal muscle BCAA oxidation, as evidenced by a higher maximal activity of the rate-determining enzyme branched-chain oxo acid dehydrogenase. Exercise-induced changes in protein metabolism are affected by nutritional status, with high carbohydrate availability (as typically practiced by endurance athletes) generally associated with reduced net protein utilisation. Ingestion of protein with carbohydrate improves net protein balance during exercise and recovery compared with carbohydrate alone, but it remains to be determined whether this practice facilitates the adaptive response to chronic training.
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Affiliation(s)
- Martin J Gibala
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
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Gelecek N, Teoman N, Ozdirenc M, Pinar L, Akan P, Bediz C, Kozan O. Influences of Acute and Chronic Aerobic Exercise on the Plasma Homocysteine Level. ANNALS OF NUTRITION AND METABOLISM 2007; 51:53-8. [PMID: 17356255 DOI: 10.1159/000100821] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2005] [Accepted: 06/02/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND AIMS Elevated plasma homocysteine (PH) levels have been identified as a risk factor for cardiovascular diseases. The aims of this study were to investigate the influences of submaximal acute aerobic exercise and aerobic training on PH levels and lipid profiles. METHODS 69 volunteer subjects (21.12 +/- 2.08 years) were randomized to three groups as acute, training and control groups. Examination and blood samples were collected before and immediately after exercise in the acute group and before and 6 weeks later in the training and control groups. RESULTS A significant increase in PH concentration was recorded immediately after aerobic exercise, compared with baseline values (p = 0.001). Although, in the training group, total cholesterol (p = 0.00) and LDL cholesterol (p = 0.001) decreased significantly after training, no significant changes in PH concentration, HDL cholesterol (p = 0.087) and triglyceride (p = 194) levels were found. CONCLUSIONS It can be said that the PH level increases following submaximal acute aerobic exercise, but does not alter after submaximal aerobic training due to training duration or intensity. Therefore, submaximal aerobic training decreases lipid profiles independent of the PH level.
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Affiliation(s)
- Nihal Gelecek
- School of Physical Therapy and Rehabilitation, Dokuz Eylul University, Izmir, Turkey.
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Gaine PC, Pikosky MA, Bolster DR, Martin WF, Maresh CM, Rodriguez NR. Postexercise Whole-Body Protein Turnover Response to Three Levels of Protein Intake. Med Sci Sports Exerc 2007; 39:480-6. [PMID: 17473774 DOI: 10.1249/mss.0b013e31802d0be4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This investigation examined the effect of variations in protein intake on whole-body protein turnover (WBPTO) after exercise in endurance-trained males. METHODS Five male runners (21.3 +/- 0.3 yr, 179 +/- 2 cm, 70.6 +/- 0.1 kg, 8.7 +/- 0.4% body fat, 70.6 +/- 0.1 VO2peak) participated in a randomized, crossover-design diet intervention, where they consumed either a low- (0.8 g.kg(-1); LP), moderate- (1.8 g.kg(-1); MP), or high-protein (3.6 g.kg(-1); HP) diet for 4 wk. WBPTO (Ra, leucine rate of appearance; NOLD, nonoxidative leucine disposal; and Ox, leucine oxidation) were assessed after a 75-min run at 70% VO2peak after each diet-intervention period. RESULTS Leucine Ra (indicator of protein breakdown) and leucine Ox were greater on the HP diet than on the LP diet (Ra, 123.4 +/- 6.9 vs 97.9 +/- 6.0 micromol.kg(-1).h(-1); Ox, 23.9 +/- 0.5 vs 17.0 +/- 0.8 micromol.kg(-1).h(-1), P < 0.05). No differences were noted in NOLD (an indicator of protein synthesis) across diets. Plasma branched chain amino acids (BCAA) at rest were greater for MP and HP than for LP, and nonessential amino acids (NEAA) were greater for LP than MP at rest and greater than MP and HP after exercise. CONCLUSION Findings from this study show that variations in protein intake can alter plasma amino acid levels and modulate rates of WBPTO after exercise. Additionally, a lower protein intake was associated with decreased rates of WBPTO after exercise.
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Tipton KD, Witard OC. Protein Requirements and Recommendations for Athletes: Relevance of Ivory Tower Arguments for Practical Recommendations. Clin Sports Med 2007; 26:17-36. [DOI: 10.1016/j.csm.2006.11.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Phillips SM. Dietary protein for athletes: from requirements to metabolic advantage. Appl Physiol Nutr Metab 2006; 31:647-54. [PMID: 17213878 DOI: 10.1139/h06-035] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Dietary Reference Intakes (DRI) specify that the requirement for dietary protein for all individuals aged 19 y and older is 0.8 g protein·kg–1·d–1. This Recommended Dietary Allowance (RDA) is cited as adequate for all persons. This amount of protein would be considered by many athletes as the amount to be consumed in a single meal, particularly for strength-training athletes. There does exist, however, published data to suggest that individuals habitually performing resistance and (or) endurance exercise require more protein than their sedentary counterparts. The RDA values for protein are clearly set at “…the level of protein judged to be adequate... to meet the known nutrient needs for practically all healthy people…”. The RDA covers protein losses with margins for inter-individual variability and protein quality; the notion of consumption of excess protein above these levels to cover increased needs owing to physical activity is not, however, given any credence. Notwithstanding, diet programs (i.e., energy restriction) espousing the virtue of high protein enjoy continued popularity. A number of well-controlled studies are now published in which “higher” protein diets have been shown to be effective in promoting weight reduction, particularly fat loss. The term “higher” refers to a diet that has people consuming more than the general populations’ average intake of ~15% of energy from protein, e.g., as much as 30%–35%, which is within an Acceptable Macronutrient Distribution Range (AMDR) as laid out in the DRIs. Of relevance to athletes and those in clinical practice is the fact that higher protein diets have quite consistently been shown to result in greater weight loss, greater fat loss, and preservation of lean mass as compared with “lower” protein diets. A framework for understanding dietary protein intake within the context of weight loss and athletic performance is laid out.
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Affiliation(s)
- Stuart M Phillips
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
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Abstract
Appropriate nutrition is an essential prerequisite for effective improvement of athletic performance, conditioning, recovery from fatigue after exercise, and avoidance of injury. Nutritional supplements containing carbohydrates, proteins, vitamins, and minerals have been widely used in various sporting fields to provide a boost to the recommended daily allowance. In addition, several natural food components have been found to show physiological effects, and some of them are considered to be useful for promoting exercise performance or for prevention of injury. However, these foods should only be used when there is clear scientific evidence and with understanding of the physiological changes caused by exercise. This article describes various "functional foods" that have been reported to be effective for improving exercise performance or health promotion, along with the relevant physiological changes that occur during exercise.
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Affiliation(s)
- Wataru Aoi
- Research Center for Sports Medicine, Doshisha University, Kyoto 602-8580, Japan
- Department of Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Yuji Naito
- Department of Medical Proteomics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Toshikazu Yoshikawa
- Department of Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
- Department of Medical Proteomics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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Lowery L, Forsythe CE. Protein and overtraining: potential applications for free-living athletes. J Int Soc Sports Nutr 2006; 3:42-50. [PMID: 18500962 PMCID: PMC2129153 DOI: 10.1186/1550-2783-3-1-42] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 04/19/2006] [Indexed: 01/02/2023] Open
Abstract
Despite a more than adequate protein intake in the general population, athletes have special needs and situations that bring it to the forefront. Overtraining is one example. Hard-training athletes are different from sedentary persons from the sub-cellular to whole-organism level. Moreover, competitive, "free-living" (less-monitored) athletes often encounter negative energy balance, sub-optimal dietary variety, injuries, endocrine exacerbations and immune depression. These factors, coupled with "two-a-day" practices and in-season demands require that protein not be dismissed as automatically adequate or worse, deleterious to health. When applying research to practice settings, one should consider methodological aspects such as population specificity and control variables such as energy balance. This review will address data pertinent to the topic of athletic protein needs, particularly from a standpoint of overtraining and soft tissue recovery. Research-driven strategies for adjusting nutrition and exercise assessments will be offered for consideration. Potentially helpful nutrition interventions for preventing and treating training complications will also be presented.
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Zello GA. Dietary Reference Intakes for the macronutrients and energy: considerations for physical activity. Appl Physiol Nutr Metab 2006; 31:74-9. [PMID: 16604146 DOI: 10.1139/h05-022] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Dietary Reference Intakes (DRIs) are the North American reference standards for nutrients in the diets of healthy individuals. The macronutrient DRI report includes the standards for energy, fat and fatty acids, carbohydrate and fiber, and protein and amino acids. Equations used to identify the Estimated Energy Requirement (EER) were also developed based on individual characteristics including levels of physical activity. The DRIs for the macronutrients are presented as Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs), as well as Acceptable Macronutrient Distribution Ranges (AMDRs), and were arrived at by considering both nutrient inadequacies and excesses. In addition, recommendations are made that would reduce the risk of chronic diseases, such as setting intake limits for added sugar; reducing cholesterol, saturated, and trans fatty acids consumption; and increasing levels of physical activity. As healthy individuals include those engaged in various levels of physical activity, the DRIs should apply to the athlete and address their macronutrient and energy needs. This paper summarizes the macronutrient DRI report as applied to the adult, with discussion of the dietary needs of those engaged in various levels of physical activity, including the athlete.Key words: nutrition, requirements, guidelines, performance, human.
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Affiliation(s)
- Gordon A Zello
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.
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Abstract
The quality of vegetarian diets to meet nutritional needs and support peak performance among athletes continues to be questioned. Appropriately planned vegetarian diets can provide sufficient energy and an appropriate range of carbohydrate, fat and protein intakes to support performance and health. The acceptable macronutrient distribution ranges for carbohydrate, fat and protein of 45-65%, 20-35% and 10-35%, respectively, are appropriate for vegetarian and non-vegetarian athletes alike, especially those who perform endurance events. Vegetarian athletes can meet their protein needs from predominantly or exclusively plant-based sources when a variety of these foods are consumed daily and energy intake is adequate. Muscle creatine stores are lower in vegetarians than non-vegetarians. Creatine supplementation provides ergogenic responses in both vegetarian and non-vegetarian athletes, with limited data supporting greater ergogenic effects on lean body mass accretion and work performance for vegetarians. The potential adverse effect of a vegetarian diet on iron status is based on the bioavailability of iron from plant foods rather than the amount of total iron present in the diet. Vegetarian and non-vegetarian athletes alike must consume sufficient iron to prevent deficiency, which will adversely affect performance. Other nutrients of concern for vegetarian athletes include zinc, vitamin B12 (cyanocobalamin), vitamin D (cholecalciferol) and calcium. The main sources of these nutrients are animal products; however, they can be found in many food sources suitable for vegetarians, including fortified soy milk and whole grain cereals. Vegetarians have higher antioxidant status for vitamin C (ascorbic acid), vitamin E (tocopherol), and beta-carotene than omnivores, which might help reduce exercise-induced oxidative stress. Research is needed comparing antioxidant defences in vegetarian and non-vegetarian athletes.
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Affiliation(s)
- Angela M Venderley
- Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana 47906-2059, USA
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Rousseau AS, Robin S, Roussel AM, Ducros V, Margaritis I. Plasma homocysteine is related to folate intake but not training status. Nutr Metab Cardiovasc Dis 2005; 15:125-133. [PMID: 15871861 DOI: 10.1016/j.numecd.2005.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Accepted: 02/11/2005] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIM Lifestyle including intakes of several essential nutrients and physical activity are of particular interest in reducing plasma total homocysteine concentration (tHcy), a risk factor for cardiovascular diseases. The aim of this study was to determine in athletes, whether dietary factors such as intakes of folate, vitamin B6 and B12 were associated with lower plasma tHcy, and whether this depended on daily energy expenditure (EE) and type of physical activity performed (aerobic, anaerobic, intermittent). METHODS Seventy-four well-trained athletes completed 7-day food and activity records in a cross-sectional study. Blood was sampled on day 8. RESULTS Percentage of vegetal protein, vitamin B6, and folate intakes were higher and tHcy was lower (1) in athletes with high EE (> 16.72 MJ/d) compared to athletes with lower EE; (2) in aerobic athletes compared to intermittent athletes and sedentary subjects. After backward step by step analysis, folate intake was the only significant variable retained in the model to explain tHcy variability. Moreover, after introducing folate intake as a covariate in ANOVA tests, group effects on tHcy were no longer significant. Nutrient density of folate was inversely correlated to tHcy in athletes (r = -0.33; P = 0.004). CONCLUSION High energy intake (> 16.72 MJ/d) allows the necessary folate intake (> 500 microg/d) for tHcy decrease to occur, which is moreover favored by aerobic activity. The mechanism underlying low tHcy in relation to high EE could only play a minor role when compared to the effect of dietary folate intake on tHcy.
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Affiliation(s)
- A S Rousseau
- Laboratoire Nutrition, Vieillissement et Maladies Cardiovasculaires, UFR Pharmacie, UJF Grenoble, France
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