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Zingg M, Rüst CA, Lepers R, Rosemann T, Knechtle B. Master runners dominate 24-h ultramarathons worldwide-a retrospective data analysis from 1998 to 2011. EXTREME PHYSIOLOGY & MEDICINE 2013; 2:21. [PMID: 23849415 PMCID: PMC3710072 DOI: 10.1186/2046-7648-2-21] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 03/15/2013] [Indexed: 11/10/2022]
Abstract
BACKGROUND The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. METHODS Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. RESULTS The number of 24-h ultra-marathoners increased for both women and men across years (P < 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 ± 5.2 years for the annual fastest men (P > 0.05). The age of the annual top ten women decreased from 42.6 ± 5.9 years (1998) to 40.1 ± 7.0 years (2011) (P < 0.01). For the annual top ten men, the age of peak running speed remained unchanged at 42 ± 2 years (P > 0.05). Running speed remained unchanged over time at 11.4 ± 0.4 km h-1 for the annual fastest men and 10.0 ± 0.2 km/h for the annual fastest women, respectively (P > 0.05). For the annual ten fastest women, running speed increased over time by 3.2% from 9.3 ± 0.3 to 9.6 ± 0.3 km/h (P < 0.01). Running speed of the annual top ten men remained unchanged at 10.8 ± 0.3 km/h (P > 0.05). Women in age groups 25-29 (r2 = 0.61, P < 0.01), 30-34 (r2 = 0.48, P < 0.01), 35-39 (r2 = 0.42, P = 0.01), 40-44 (r2 = 0.46, P < 0.01), 55-59 (r2 = 0.41, P = 0.03), and 60-64 (r2 = 0.57, P < 0.01) improved running speed; while women in age groups 45-49 and 50-54 maintained running speed (P > 0.05). Men improved running speed in age groups 25-29 (r2 = 0.48, P = 0.02), 45-49 (r2 = 0.34, P = 0.03), 50-54 (r2 = 0.50, P < 0.01), 55-59 (r2 = 0.70, P < 0.01), and 60-64 (r2 = 0.44, P = 0.03); while runners in age groups 30-34, 35-39, and 40-44 maintained running speed (P > 0.05). CONCLUSIONS Female and male age group runners improved running speed. Runners aged >40 years achieved the fastest running speeds. By definition, runners aged >35 are master runners. The definition of master runners aged >35 years needs to be questioned for ultra-marathoners competing in 24-h ultra-marathons.
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Affiliation(s)
- Matthias Zingg
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland.
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302
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Bottoms L, Greenhalgh A, Gregory K. The effect of caffeine ingestion on skill maintenance and fatigue in epee fencers. J Sports Sci 2013; 31:1091-9. [DOI: 10.1080/02640414.2013.764466] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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303
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Zingg MA, Knechtle B, Rüst CA, Rosemann T, Lepers R. Reduced performance difference between sexes in master mountain and city marathon running. Int J Gen Med 2013; 6:267-75. [PMID: 23637550 PMCID: PMC3636808 DOI: 10.2147/ijgm.s44115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background The performance in master marathoners has been investigated in flat city marathons but not in mountain marathons. This study examined changes in the sex differences in performance across time in female and male master runners competing in a mountain marathon compared to a flat city marathon. Methods The association between age and performance of finishers in the Jungfrau Marathon, Switzerland, with 1830 meter changes in altitude and a flat city marathon (Lausanne Marathon), Switzerland, were analyzed from 2000 to 2011. Results In both events, athletes in the 35–44 years age group showed the highest number of finishers. In the mountain marathon, the number of female master runners aged > 35 years increased in contrast to female finishers aged < 35 years, while the number of male finishers was unchanged in all age groups. In the city marathon, the number of female finishers was unchanged while the number of male finishers in the age groups for 25–34-year-olds and 35–44-year-olds decreased. In female marathoners, performance improved in athletes aged 35–44 and 55–64 years in the city marathon. Male marathoners improved race time in age group 45–54 years in both the city marathon and the mountain marathon. Female master runners reduced the sex difference in performance in the 45–54-year age group in both competitions and in the 35–44-year age group in the mountain marathon. The sex difference in performance decreased in the 35–44-year age group from 19.1% ± 4.7% to 16.6% ± 1.9% in the mountain marathon (r2 = 0.39, P = 0.03). In age groups 45–54 years, the sex difference decreased from 23.4% ± 1.9% to 15.9% ± 6.1% in the mountain marathon (r2 = 0.39, P < 0.01) and from 34.7% ± 4.6% to 11.8% ± 6.2% in the city marathon (r2 = 0.39, P < 0.01). Conclusion These findings suggest that female master runners aged 35–54 years reduced sex differences in their performance in both mountain and city marathon running.
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Affiliation(s)
- Matthias A Zingg
- Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland
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304
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Margolis LM, Rood J, Champagne C, Young AJ, Castellani JW. Energy balance and body composition during US Army special forces training. Appl Physiol Nutr Metab 2013; 38:396-400. [DOI: 10.1139/apnm-2012-0323] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Small Unit Tactics (SUT) is a 64-day phase of the Special Forces Qualification Course designed to simulate real-world combat operations. Assessing the metabolic and physiological responses of such intense training allows greater insights into nutritional requirements of soldiers during combat. The purpose of this study was to examine energy balance around specific training events, as well as changes in body mass and composition. Data were collected from 4 groups of soldiers (n = 36) across 10-day periods. Participants were 28 ± 5 years old, 177 ± 6 cm tall, and weighed 83 ± 7 kg. Doubly labeled water (D218O) was used to assess energy expenditure. Energy intake was calculated by subtracting energy in uneaten foods from known energy in distributed foods in individually packaged combat rations or in the dining facility. Body composition was estimated from skinfold thickness measurements on days 0 and 64 of the course. Simulated urban combat elicited that largest energy deficit (11.3 ± 2.3 MJ·day−1 (2700 ± 550 kcal·day−1); p < 0.05), and reduction in body mass (3.3 ± 1.9 kg; p < 0.05), during SUT, while energy balance was maintained during weapons familiarization training and platoon size raids. Over the entire course body mass decreased by 4.2 ± 3.7 kg (p < 0.01), with fat mass decreasing by 2.8 ± 2.0 kg (p < 0.01) and fat-free mass decreasing by 1.4 ± 2.8 kg (p < 0.05). The overall reduction in body mass suggests that soldiers were in a negative energy balance during SUT, with high energy deficit being observed during strenuous field training.
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Affiliation(s)
- Lee M. Margolis
- United States Army Research Institute of Environmental Medicine, 42 Kansas St, Natick, MA 01760, USA
| | - Jennifer Rood
- Pennington Biomedical Research Center, 6400 Perkins Rd, Baton Rouge, LA 70808, USA
| | - Catherine Champagne
- Pennington Biomedical Research Center, 6400 Perkins Rd, Baton Rouge, LA 70808, USA
| | - Andrew J. Young
- United States Army Research Institute of Environmental Medicine, 42 Kansas St, Natick, MA 01760, USA
| | - John W. Castellani
- United States Army Research Institute of Environmental Medicine, 42 Kansas St, Natick, MA 01760, USA
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Abstract
Adventure racing requires competitors to perform various disciplines ranging from, but not limited to, mountain biking, running, kayaking, climbing, mountaineering, flat- and white-water boating and orienteering over a rugged, often remote and wilderness terrain. Races can vary from 6 hours to expedition-length events that can last up to 10-consecutive days or more. The purpose of this article is to provide evidence-based nutritional recommendations for adventure racing competitors. Energy expenditures of 365-750 kcal/hour have been reported with total energy expenditures of 18 000-80 000 kcal required to complete adventure races, and large negative energy balances during competitions have been reported. Nutrition, therefore, plays a major role in the successful completion of such ultra-endurance events. Conducting research in these events is challenging and the limited studies investigating dietary surveys and nutritional status of adventure racers indicate that competitors do not meet nutrition recommendations for ultra-endurance exercise. Carbohydrate intakes of 7-12 g/kg are needed during periods of prolonged training to meet requirements and replenish glycogen stores. Protein intakes of 1.4-1.7 g/kg are recommended to build and repair tissue. Adequate replacement of fluid and electrolytes are crucial, particularly during extreme temperatures; however, sweat rates can vary greatly between competitors. There is considerable evidence to support the use of sports drinks, gels and bars, as they are a convenient and portable source of carbohydrate that can be consumed during exercise, in training and in competition. Similarly, protein and amino acid supplements can be useful to help meet periods of increased protein requirements. Caffeine can be used as an ergogenic aid to help competitors stay awake during prolonged periods, enhance glycogen resynthesis and enhance endurance performance.
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Affiliation(s)
- Mayur K Ranchordas
- Sheffield Hallam University, Academy of Sport and Physical Activity, Collegiate Crescent Campus, Sheffield, UK.
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306
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Storey A, Smith HK. Unique aspects of competitive weightlifting: performance, training and physiology. Sports Med 2013; 42:769-90. [PMID: 22873835 DOI: 10.1007/bf03262294] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Weightlifting is a dynamic strength and power sport in which two, multijoint, whole-body lifts are performed in competition; the snatch and clean and jerk. During the performance of these lifts, weightlifters have achieved some of the highest absolute and relative peak power outputs reported in the literature. The training structure of competitive weightlifters is characterized by the frequent use of high-intensity resistance exercise movements. Varied coaching and training philosophies currently exist around the world and further research is required to substantiate the best type of training programme for male and female weightlifters of various age groups. As competitive weightlifting is contested over eight male and seven female body weight categories, the anthropometric characteristics of the athletes widely ranges. The body compositions of weightlifters are similar to that of athletes of comparable body mass in other strength and power sports. However, the shorter height and limb lengths of weightlifters provide mechanical advantages when lifting heavy loads by reducing the mechanical torque and the vertical distance that the barbell must be displaced. Furthermore, the shorter body dimensions coincide with a greater mean skeletal muscle cross-sectional area that is advantageous to weightlifting performance. Weightlifting training induces a high metabolic cost. Although dietary records demonstrate that weightlifters typically meet their required daily energy intake, weightlifters have been shown to over consume protein and fat at the expense of adequate carbohydrate. The resulting macronutrient imbalance may not yield optimal performance gains. Cross-sectional data suggest that weightlifting training induces type IIX to IIA fibre-type transformation. Furthermore, weightlifters exhibit hypertrophy of type II fibres that is advantageous to weightlifting performance and maximal force production. As such, the isometric peak force and contractile rate of force development of weightlifters is ~15-20% and ~13-16% greater, respectively, than in other strength and power athletes. In addition, weightlifting training has been shown to reduce the typical sex-related difference in the expression of neuromuscular strength and power. However, this apparent sex-related difference appears to be augmented with increasing adult age demonstrating that women undergo a greater age-related decline in muscle shortening velocity and peak power when compared with men. Weightlifting training and competition has been shown to induce significant structural and functional adaptations of the cardiovascular system. The collective evidence shows that these adaptations are physiological as opposed to pathological. Finally, the acute exercise-induced testosterone, cortisol and growth hormone responses of weightlifters have similarities to that of following conventional strength and hypertrophy protocols involving large muscle mass exercises. The routine assessment of the basal testosterone : cortisol ratio may be beneficial when attempting to quantify the adaptive responses to weightlifting training. As competitive weightlifting is becoming increasingly popular around the world, further research addressing the physiological responses and adaptations of female weightlifters and younger (i.e. ≤17 years of age) and older (i.e. ≥35 years of age) weightlifters of both sexes is required.
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Affiliation(s)
- Adam Storey
- Department of Sport and Exercise Science, The University of Auckland, Auckland, New Zealand.
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307
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Molina-López J, Molina JM, Chirosa LJ, Florea DI, Sáez L, Planells E. Effect of folic acid supplementation on homocysteine concentration and association with training in handball players. J Int Soc Sports Nutr 2013; 10:10. [PMID: 23432819 PMCID: PMC3605276 DOI: 10.1186/1550-2783-10-10] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 12/31/2012] [Indexed: 02/07/2023] Open
Abstract
Background Strenuous physical activity can alter the status of folic acid, a vitamin directly associated with homocysteine (Hcy); alterations in this nutrient are a risk factor for cardiovascular disease. Handball players are a population at risk for nutrient deficiency because of poor dietary habits. Objective The aims of this study were to evaluate nutritional status for macronutrients and folic acid in members of a high-performance handball team, and determine the effect of a nutritional intervention with folic acid supplementation and education. Design A total of 14 high-performance handball players were monitored by recording training time, training intensity (according to three levels of residual heart rate (RHR): <60%, 60%–80% and >80%), and subjective perceived exertion (RPE) during a 4-month training period. Nutritional, laboratory and physical activity variables were recorded at baseline (Week 0), after 2 months of dietary supplementation with 200 μg folic acid (50% of the recommended daily allowance) (Week 8) and after 2 months without supplementation (Week 16). We compared training load and analyzed changes in plasma concentrations of Hcy before and after the intervention. Results Bivariate analysis showed a significant negative correlation (P < 0.01) between Hcy and folic acid concentrations (r = −0.84) at Week 8, reflecting a significant change in Hcy concentration (P < 0.05) as a result of hyperhomocysteinemia following the accumulation of high training loads. At Week 16 we observed a significant negative correlation (P < 0.01) between Hcy concentration and training time with an RHR <60%, indicating that aerobic exercise avoided abrupt changes in Hcy and may thus reduce the risk of cardiovascular accidents in high-performance athletes. Conclusion Integral monitoring and education are needed for practitioners of handball sports to record their folic acid status, a factor that directly affects Hcy metabolism. Folic acid supplementation may protect athletes against alterations that can lead to cardiovascular events related to exertion during competition.
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Affiliation(s)
- Jorge Molina-López
- Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada 18071, Spain
| | - José M Molina
- Department of Physical Education and Sports, Faculty of Sports Sciences, University of Granada, Granada 18071, Spain
| | - Luís J Chirosa
- Department of Physical Education and Sports, Faculty of Sports Sciences, University of Granada, Granada 18071, Spain
| | - Daniela I Florea
- Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada 18071, Spain
| | - Laura Sáez
- Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada 18071, Spain
| | - Elena Planells
- Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada 18071, Spain
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308
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Hill KM, Stathis CG, Grinfeld E, Hayes A, McAinch AJ. Co-ingestion of carbohydrate and whey protein isolates enhance PGC-1α mRNA expression: a randomised, single blind, cross over study. J Int Soc Sports Nutr 2013; 10:8. [PMID: 23402493 PMCID: PMC3577454 DOI: 10.1186/1550-2783-10-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 02/07/2013] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Whey protein isolates (WPI) supplementation is known to improve resistance training adaptations. However, limited information is available on the effects of WPI plus carbohydrate (CHO) supplementation on endurance training adaptations. METHOD Six endurance trained male cyclists and triathletes (age 29 ± 4 years, weight 74 ± 2 kg, VO2 max 63 ± 3 ml oxygen. kg-1. Min-1, height 183 ± 5 cm; mean ± SEM) were randomly assigned to one of two dietary interventions in a single blind cross over design; CHO or CHO + WPI. Each dietary intervention was followed for 16 days which included the last 2 days having increased CHO content, representing a CHO loading phase. The dietary interventions were iso-caloric and carbohydrate content matched. On completion of the dietary intervention, participants performed an exercise bout, consisting of cycling for 60 min at 70% VO2 max, followed by time trial to exhaustion at 90% VO2 max and recovered in the laboratory for 6 hours. Blood samples and muscle biopsies were taken at various time points at rest and through the exercise trial and recovery. RESULTS Compared to CHO, CHO + WPI increased plasma insulin during recovery at 180 mins (P < 0.05) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) mRNA expression at the end of 6 hours of recovery (P < 0.05). Muscle glycogen did not differ between the two trials. CONCLUSION This study showed co-ingestion of CHO + WPI may have beneficial effects on recovery and adaptations to endurance exercise via, increased insulin response and up regulation of PGC-1α mRNA expression.
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Affiliation(s)
- Karen M Hill
- Biomedical and Lifestyle Diseases Unit, College of Health and Biomedicine, Victoria University, PO Box 14428, Melbourne, VIC 8001, Australia.
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309
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Santos DA, Gobbo LA, Matias CN, Petroski EDIOL, Gonçalves EM, Cyrino ES, Minderico CS, Sardinha LB, Silva AM. Body composition in taller individuals using DXA: A validation study for athletic and non-athletic populations. J Sports Sci 2013; 31:405-13. [PMID: 23092580 DOI: 10.1080/02640414.2012.734918] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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310
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Lane SC, Bird SR, Burke LM, Hawley JA. Effect of a carbohydrate mouth rinse on simulated cycling time-trial performance commenced in a fed or fasted state. Appl Physiol Nutr Metab 2013; 38:134-9. [DOI: 10.1139/apnm-2012-0300] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is presently unclear whether the reported ergogenic effect of a carbohydrate (CHO) mouth rinse on cycling time-trial performance is affected by the acute nutritional status of an individual. Hence, the aim of this study was to investigate the effect of a CHO mouth rinse on a 60-min simulated cycling time-trial performance commenced in a fed or fasted state. Twelve competitive male cyclists each completed 4 experimental trials using a double-blinded Latin square design. Two trials were commenced 2 h after a meal that contained 2.5 g·kg−1 body mass of CHO (FED) and 2 after an overnight fast (FST). Prior to and after every 12.5% of total time during a performance ride, either a 10% maltodextrin (CHO) or a taste-matched placebo (PLB) solution was mouth rinsed for 10 s then immediately expectorated. There were significant main effects for both pre-ride nutritional status (FED vs. FST; p < 0.01) and CHO mouth rinse (CHO vs. PLB; p < 0.01) on power output with an interaction evident between the interventions (p < 0.05). The CHO mouth rinse improved mean power to a greater extent after an overnight fast (282 vs. 273 W, 3.4%; p < 0.01) compared with a fed state (286 vs. 281 W, 1.8%; p < 0.05). We concluded that a CHO mouth rinse improved performance to a greater extent in a fasted compared with a fed state; however, optimal performance was achieved in a fed state with the addition of a CHO mouth rinse.
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Affiliation(s)
- Stephen C. Lane
- Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Stephen R. Bird
- Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Louise M. Burke
- Sports Nutrition, Australian Institute of Sport, Belconnen, ACT 2626, Australia
| | - John A. Hawley
- Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, VIC 3083, Australia
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311
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Bartlett JD, Louhelainen J, Iqbal Z, Cochran AJ, Gibala MJ, Gregson W, Close GL, Drust B, Morton JP. Reduced carbohydrate availability enhances exercise-induced p53 signaling in human skeletal muscle: implications for mitochondrial biogenesis. Am J Physiol Regul Integr Comp Physiol 2013; 304:R450-8. [PMID: 23364526 DOI: 10.1152/ajpregu.00498.2012] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The mechanisms that regulate the enhanced skeletal muscle oxidative capacity observed when training with reduced carbohydrate (CHO) availability are currently unknown. The aim of the present study was to test the hypothesis that reduced CHO availability enhances p53 signaling and expression of genes associated with regulation of mitochondrial biogenesis and substrate utilization in human skeletal muscle. In a repeated-measures design, muscle biopsies (vastus lateralis) were obtained from eight active males before and after performing an acute bout of high-intensity interval running with either high (HIGH) or low CHO availability (LOW). Resting muscle glycogen (HIGH, 467 ± 19; LOW, 103 ± 9 mmol/kg dry wt) was greater in HIGH compared with LOW (P < 0.05). Phosphorylation (P-) of ACC(Ser79) (HIGH, 1.4 ± 0.4; LOW, 2.9 ± 0.9) and p53(Ser15) (HIGH, 0.9 ± 0.4; LOW, 2.6 ± 0.8) was higher in LOW immediately postexercise and 3 h postexercise, respectively (P < 0.05). Before and 3 h postexercise, mRNA content of pyruvate dehydrogenase kinase 4, mitochondrial transcription factor A, cytochrome-c oxidase IV, and PGC-1α were greater in LOW compared with HIGH (P < 0.05), whereas carnitine palmitoyltransferase-1 showed a trend toward significance (P = 0.09). However, only PGC-1α expression was increased by exercise (P < 0.05), where three-fold increases occurred independently of CHO availability. We conclude that the exercise-induced increase in p53 phosphorylation is enhanced in conditions of reduced CHO availability, which may be related to upstream signaling through AMPK. Given the emergence of p53 as a molecular regulator of mitochondrial biogenesis, such nutritional modulation of contraction-induced p53 activation has implications for both athletic and clinical populations.
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Affiliation(s)
- Jonathan D Bartlett
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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312
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Koehler K, Achtzehn S, Braun H, Mester J, Schaenzer W. Comparison of self-reported energy availability and metabolic hormones to assess adequacy of dietary energy intake in young elite athletes. Appl Physiol Nutr Metab 2013; 38:725-33. [PMID: 23980730 DOI: 10.1139/apnm-2012-0373] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous intervention studies suggest that leptin, insulin, insulin-like growth factor 1 (IGF-1), and triiodthyronine (T3) are sensitive markers of inadequate energy intake in relation to exercise expenditures. Because of limitations in metabolic hormone measurements, self-reported energy availability (EA) based on food and activity records may present an alternative for characterizing energy status in young athletes. The purpose of the current study was to assess whether self-reported EA is related to leptin, insulin, IGF-1, and T3 in 352 young athletes. Sex, body composition, sport participation, and acute weight changes were considered as confounding variables. Multiple linear regression revealed that EA was negatively associated with leptin (p < 0.05) but not with insulin, IGF-1, or T3. Female athletes with low EA (<30 kcal·kg(-1) fat-free mass (FFM)) had higher leptin concentrations (5.0 ± 4.7 ng·mL(-1)) and more body fat (18.3% ± 5.1%) than did females with normal EA (leptin, 3.1 ± 2.4 ng·mL(-1); body fat, 15.8% ± 4.2%; both, p < 0.001). Athletes reporting acute weight loss (>1 kg·week(-1)) had a lower EA (18.9 ± 7.4 kcal·kg(-1) FFM) than did weight-stable athletes (30.0 ± 11.2 kcal·kg(-1) FFM) or athletes reporting weight gain (>1 kg; 49.7 ± 13.1 kcal·kg(-1) FFM). IGF-1 and T3 were also reduced in athletes who lost weight (p < 0.01). This cross-sectional study reveals a lack of association between self-reported EA and metabolic hormones indicative of energy status in young athletes. Further studies are needed to investigate whether self-reported EA and metabolic hormones are in better agreement when measured repeatedly.
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Affiliation(s)
- Karsten Koehler
- Institute of Biochemistry, German Sport University, Am Sportpark Muengersdorf 6, D-50933 Cologne, Germany.
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313
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Colombani PC, Mannhart C, Mettler S. Carbohydrates and exercise performance in non-fasted athletes: a systematic review of studies mimicking real-life. Nutr J 2013; 12:16. [PMID: 23356905 PMCID: PMC3570376 DOI: 10.1186/1475-2891-12-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 01/22/2013] [Indexed: 11/10/2022] Open
Abstract
There is a consensus claiming an ergogenic effect of carbohydrates ingested in the proximity of or during a performance bout. However, in performance studies, the protocols that are used are often highly standardized (e.g. fasted subjects, constant exercise intensity with time-to-exhaustion tests), and do not necessarily reflect competitive real-life situations. Therefore, we aimed at systematically summarizing all studies with a setting mimicking the situation of a real-life competition (e.g., subjects exercising in the postprandial state and with time-trial-like performance tests such as fixed distance or fixed time tests). We performed a PubMed search by using a selection of search terms covering inclusion criteria for sport, athletes, carbohydrates, and fluids, and exclusion criteria for diseases and animals. This search yielded 16,658 articles and the abstract of 16,508 articles contained sufficient information to identify the study as non-eligible for this review. The screening of the full text of the remaining 150 articles yielded 17 articles that were included in this review. These articles described 22 carbohydrate interventions covering test durations from 26 to 241 min (mostly cycling). We observed no performance improvement with half of the carbohydrate interventions, while the other half of the interventions had significant improvement between 1% and 13% (improvement with one of five interventions lasting up to 68 min and with 10 of 17 interventions lasting between 70 and 241 min). Thus, when considering only studies with a setting mimicking real-life competition, there is a mixed general picture about the ergogenic effect of carbohydrates ingested in the proximity of or during a performance bout with an unlikely effect with bouts up to perhaps 70 min and a possible but not compelling ergogenic effect with performance durations longer than about 70 min.
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Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study. Nutr J 2013; 12:13. [PMID: 23320854 PMCID: PMC3554439 DOI: 10.1186/1475-2891-12-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Accepted: 01/11/2013] [Indexed: 12/14/2022] Open
Abstract
Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74) and control (CON, n = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (p < 0.001 vs. CON). Exercise-induced BM loss was 2.4 (1.2)% (p < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (p > 0.05 vs. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (p < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON. Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.
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315
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Torres-McGehee TM, Pritchett KL, Zippel D, Minton DM, Cellamare A, Sibilia M. Sports nutrition knowledge among collegiate athletes, coaches, athletic trainers, and strength and conditioning specialists. J Athl Train 2013; 47:205-11. [PMID: 22488287 DOI: 10.4085/1062-6050-47.2.205] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Coaches, athletic trainers (ATs), strength and conditioning specialists (SCSs), and registered dietitians are common nutrition resources for athletes, but coaches, ATs, and SCSs might offer only limited nutrition information. Little research exists about sports nutrition knowledge and current available resources for nutrition information for athletes, coaches, ATs, and SCSs. OBJECTIVE To identify resources of nutrition information that athletes, coaches, ATs, and SCSs use; to examine nutrition knowledge among athletes, coaches, ATs, and SCSs; and to determine confidence levels in the correctness of nutrition knowledge questions within all groups. DESIGN Cross-sectional study. SETTING National Collegiate Athletic Association Division I, II, and III institutions across the United States. PATIENTS AND OTHER PARTICIPANTS The 579 participants consisted of athletes (n = 185), coaches (n = 131), ATs (n = 192), and SCSs (n = 71). MAIN OUTCOME MEASURE(S) Participants answered questions about nutrition resources and domains regarding basic nutrition, supplements and performance, weight management, and hydration. Adequate sports nutrition knowledge was defined as an overall score of 75% in all domains (highest achievable score was 100%). RESULTS Participants averaged 68.5% in all domains. The ATs (77.8%) and SCSs (81.6%) had the highest average scores. Adequate knowledge was found in 35.9% of coaches, 71.4% of ATs, 83.1% of SCSs, and only 9% of athletes. The most used nutrition resources for coaches, ATs, and SCSs were registered dietitians. CONCLUSIONS Overall, we demonstrated that ATs and SCSs have adequate sports nutrition knowledge, whereas most coaches and athletes have inadequate knowledge. Athletes have frequent contact with ATs and SCSs; therefore, proper nutrition education among these staff members is critical. We suggest that proper nutrition programming should be provided for athletes, coaches, ATs, and SCSs. However, a separate nutrition program should be integrated for ATs and SCSs. This integrative approach is beneficial for the continuity of care, as both categories of professionals might be developing and integrating preventive or rehabilitative programs for athletes.
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316
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Coelho GMDO, de Farias MLF, de Mendonça LMC, de Mello DB, Lanzillotti HS, Ribeiro BG, Soares EDA. The prevalence of disordered eating and possible health consequences in adolescent female tennis players from Rio de Janeiro, Brazil. Appetite 2013; 64:39-47. [PMID: 23318655 DOI: 10.1016/j.appet.2013.01.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 12/23/2012] [Accepted: 01/06/2013] [Indexed: 10/27/2022]
Abstract
The aim of this study was to estimate the prevalence of disordered eating and possible health consequences in adolescent female tennis players. This cross-sectional controlled study investigated the pubertal development (Tanner stages); body composition (dual energy X-ray absorptiometry-DXA); dietary intake (food record); presence of disordered eating (EAT-26, BITE and BSQ); menstrual status (questionnaire) and bone mineral density (DXA). The Female Athlete Triad (FAT) was divided into two severity stages. The study included 45 adolescents (24 athletes and 21 controls) at some pubertal developmental stage. The athletes exhibited better body composition profiles. We found that 91.7%, 33.3% and 25% of athletes and 71.4%, 9.5% and 33.3% of controls met criteria for disordered eating and/or low energy availability, menstrual irregularities and low bone mass, respectively. A greater percentage of athletes than controls presented with 1 and 2 FAT components (stage I), and 4.2% presented with the full syndrome. In conclusion, tennis players appear to present with more severe disorders than controls and should be monitored to avoid damage to their performance and health.
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317
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Campbell B, Wilborn C, La Bounty P, Taylor L, Nelson MT, Greenwood M, Ziegenfuss TN, Lopez HL, Hoffman JR, Stout JR, Schmitz S, Collins R, Kalman DS, Antonio J, Kreider RB. International Society of Sports Nutrition position stand: energy drinks. J Int Soc Sports Nutr 2013; 10:1. [PMID: 23281794 PMCID: PMC3538552 DOI: 10.1186/1550-2783-10-1] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 12/31/2012] [Indexed: 12/18/2022] Open
Abstract
Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the safety and efficacy of the use of energy drinks (ED) or energy shots (ES). The ISSN has concluded the following. 1. Although ED and ES contain a number of nutrients that are purported to affect mental and/or physical performance, the primary ergogenic nutrients in most ED and ES appear to be carbohydrate and/or caffeine. 2. The ergogenic value of caffeine on mental and physical performance has been well-established but the potential additive benefits of other nutrients contained in ED and ES remains to be determined. 3. Consuming ED 10-60 minutes before exercise can improve mental focus, alertness, anaerobic performance, and/or endurance performance. 4. Many ED and ES contain numerous ingredients; these products in particular merit further study to demonstrate their safety and potential effects on physical and mental performance. 5. There is some limited evidence that consumption of low-calorie ED during training and/or weight loss trials may provide ergogenic benefit and/or promote a small amount of additional fat loss. However, ingestion of higher calorie ED may promote weight gain if the energy intake from consumption of ED is not carefully considered as part of the total daily energy intake. 6. Athletes should consider the impact of ingesting high glycemic load carbohydrates on metabolic health, blood glucose and insulin levels, as well as the effects of caffeine and other stimulants on motor skill performance. 7. Children and adolescents should only consider use of ED or ES with parental approval after consideration of the amount of carbohydrate, caffeine, and other nutrients contained in the ED or ES and a thorough understanding of the potential side effects. 8. Indiscriminant use of ED or ES, especially if more than one serving per day is consumed, may lead to adverse events and harmful side effects. 9. Diabetics and individuals with pre-existing cardiovascular, metabolic, hepatorenal, and neurologic disease who are taking medications that may be affected by high glycemic load foods, caffeine, and/or other stimulants should avoid use of ED and/or ES unless approved by their physician.
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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
| | - Colin Wilborn
- Human Performance Laboratory, University of Mary Hardin-Baylor, Belton, TX, 76513, USA
| | - Paul La Bounty
- Department of Health, Human Performance, and Recreation, Baylor University, Box 97313, Waco, TX, 76798, USA
| | - Lem Taylor
- Human Performance Laboratory, University of Mary Hardin-Baylor, Belton, TX, 76513, USA
| | - Mike T Nelson
- Department of Health and Human Performance, University of St.Thomas, St. Paul, MN, 55105, USA
| | - Mike Greenwood
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, Texas, TX, 77843-4243, USA
| | | | - Hector L Lopez
- The Center for Applied Health Sciences, Stow, OH, 44224, USA
| | - Jay R Hoffman
- Institute of Exercise Physiology and Wellness, Department of Sport and Exercise Science, University of Central Florida, Orlando, FL, 32816, USA
| | - Jeffrey R Stout
- Institute of Exercise Physiology and Wellness, Department of Sport and Exercise Science, University of Central Florida, Orlando, FL, 32816, USA
| | - Stephen Schmitz
- Medical Surveillance and Risk Management, Shire HGT, 300 Shire Way, Lexington, MA, 02421, USA
| | | | - Doug S Kalman
- Miami Research Associates, Endocrinology & Nutrition Department, 6141 Sunset Drive - Suite 301, Miami, FL, 33143, USA
| | - Jose Antonio
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Richard B Kreider
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, Texas, TX, 77843-4243, USA
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NANA ALISA, SLATER GARYJ, HOPKINS WILLG, BURKE LOUISEM. Effects of Exercise Sessions on DXA Measurements of Body Composition in Active People. Med Sci Sports Exerc 2013; 45:178-85. [DOI: 10.1249/mss.0b013e31826c9cfd] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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319
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Chatterton JM, Petrie TA. Prevalence of disordered eating and pathogenic weight control behaviors among male collegiate athletes. Eat Disord 2013; 21:328-41. [PMID: 23767673 DOI: 10.1080/10640266.2013.797822] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The aim of this study was to determine the prevalence of disordered eating and pathogenic weight control behaviors in male collegiate athletes. Male collegiate athletes (N = 732) from the across the U.S. completed questionnaires online. Results suggested that (a) most eating disturbances occur at the subclinical level, (b) exercising and dieting were the most commonly used weight control practices, and (c) athletes who participate in weight class sports are more likely to be classified as symptomatic and engage in pathogenic eating and weight control behaviors compared to endurance sport or ball game athletes. Implications for professionals working with athletes and recommendations for future research are discussed.
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320
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Rodek J, Sekulic D, Kondric M. Dietary supplementation and doping-related factors in high-level sailing. J Int Soc Sports Nutr 2012; 9:51. [PMID: 23217197 PMCID: PMC3536606 DOI: 10.1186/1550-2783-9-51] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 12/03/2012] [Indexed: 01/26/2023] Open
Abstract
Background Although dietary supplements (DSs) in sports are considered a natural need resulting from athletes’ increased physical demands, and although they are often consumed by athletes, data on DS usage in Olympic sailing are scarce. The aim of this study was to study the use of and attitudes towards DSs and doping problems in high-level competitive sailing. Methods The sample consisted of 44 high-level sailing athletes (5 of whom were female; total mean age 24.13 ± 6.67 years) and 34 coaches (1 of whom was female; total mean age 37.01 ± 11.70). An extensive, self-administered questionnaire of substance use was used, and the subjects were asked about sociodemographic data, sport-related factors, DS-related factors (i.e., usage of and knowledge about DSs, sources of information), and doping-related factors. The Kruskal-Wallis ANOVA was used to determine the differences in group characteristics, and Spearman’s rank order correlation and a logistic regression analysis were used to define the relationships between the studied variables. Results DS usage is relatively high. More than 77% of athletes consume DSs, and 38% do so on a regular basis (daily). The athletes place a high degree of trust in their coaches and/or physicians regarding DSs and doping. The most important reason for not consuming DSs is the opinion that DSs are useless and a lack of knowledge about DSs. The likelihood of doping is low, and one-third of the subjects believe that doping occurs in sailing (no significant differences between athletes and coaches). The logistic regression found crew number (i.e., single vs. double crew) to be the single significant predictor of DS usage, with a higher probability of DS consumption among single crews. Conclusion Because of the high consumption of DSs future investigations should focus on real nutritional needs in sailing sport. Also, since athletes reported that their coaches are the primary source of information about nutrition and DSs, further studies are necessary to determine the knowledge about nutrition, DSs and doping problems among athletes and their support teams (i.e., coaches, physicians, and strength and conditioning specialists).
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Affiliation(s)
- Jelena Rodek
- Faculty of Kinesiology, University of Split, Teslina 6, Split, 21000, Croatia.
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Bratland-Sanda S, Sundgot-Borgen J. Eating disorders in athletes: overview of prevalence, risk factors and recommendations for prevention and treatment. Eur J Sport Sci 2012; 13:499-508. [PMID: 24050467 DOI: 10.1080/17461391.2012.740504] [Citation(s) in RCA: 205] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The prevalence of disordered eating and eating disorders vary from 0-19% in male athletes and 6-45% in female athletes. The objective of this paper is to present an overview of eating disorders in adolescent and adult athletes including: (1) prevalence data; (2) suggested sport- and gender-specific risk factors and (3) importance of early detection, management and prevention of eating disorders. Additionally, this paper presents suggestions for future research which includes: (1) the need for knowledge regarding possible gender-specific risk factors and sport- and gender-specific prevention programmes for eating disorders in sports; (2) suggestions for long-term follow-up for female and male athletes with eating disorders and (3) exploration of a possible male athlete triad.
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Affiliation(s)
- Solfrid Bratland-Sanda
- a Department of Sport and Outdoor Life Science , Telemark University College , Bø , Norway
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322
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Rüst CA, Knechtle B, Rosemann T. Women achieve peak freestyle swim speed at earlier ages than men. Open Access J Sports Med 2012; 3:189-99. [PMID: 24198602 PMCID: PMC3781914 DOI: 10.2147/oajsm.s38174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background The age of peak swim performance has been investigated for freestyle swimmers for distances ranging from 50 m to 1500 m among swimmers aged 19 to 99 years. However, studies have yet to investigate the 10 to 19 year-old age group. The aims of the present study were (1) to investigate the age range of peak freestyle swim speed, and (2) to find differences in age range and peak freestyle swim speed between male and female freestyle swimmers from 50 m to 1500 m at a national level. Methods The changes in age range and peak freestyle swim speed among Swiss elite freestyle swimmers aged 0–9 years and 70–79 years who were ranked on the Swiss high score list between 2006 and 2010 were analyzed using linear regression analyses and analysis of variance. Results Men were fastest at ages 22–23 years for 100 m and 200 m; at ages 24–25 years for 400 m and 800 m; and at 26–27 years for 50 m and 1500 m. Women achieved peak freestyle swim speed at ages 20–21 years for all distances with the exception of 800 m. In the 800 m, women were fastest at ages 26–27 years. The difference in peak freestyle swim speed decreased with increasing swim distance from 50 m to 800 m (ie, 13.1% ± 1.3% in 50 m; 13.2% ± 0.9% in 100 m; 10.8% ± 0.9% in 200 m; 7.9% ± 1.3% in 400 m; and 4.2% ± 2.0% in 800 m). For 1500 m, however, the gender difference increased to 6.4% ± 2.3%. Conclusion These findings suggest that peak freestyle swim speed is achieved at lower age ranges in women when compared to men at 50 m to 1500 m, but not at 800 m. The gender difference in peak freestyle swim speed decreased with increasing swim distance from 50 m to 800 m, but not for 1500 m. These data should be confirmed with swimmers at an international level.
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Affiliation(s)
- Christoph Alexander Rüst
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland
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323
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Metabolism and performance during extended high-intensity intermittent exercise after consumption of low- and high-glycaemic index pre-exercise meals. Br J Nutr 2012; 108 Suppl 1:S81-90. [PMID: 22916819 DOI: 10.1017/s0007114512000840] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The metabolic and performance benefits of prior consumption of low-glycaemic index (GI) meals v. high-GI meals were determined in extended high-intensity intermittent exercise. Participants (ten males and four females, aged 25·8 (sd 7·3) years) completed two testing days (each consisting of back-to-back 90-min intermittent high-intensity treadmill running protocols separated by 3 h) spaced by at least 7 d. Using a randomised counterbalanced cross-over design, low-GI, lentil-based meals (GI about 42) or high-GI, potato-based meals (GI about 78) matched for energy value were consumed 2 h before, and within 1 h after, the first exercise session. Performance was measured by the distance covered during five 1-min sprints (separated by 2·5 min walking) at the end of each exercise session. Peak postprandial blood glucose was higher by 30·8 % in the high-GI trial compared with the low-GI trial, as was insulin (P = 0·039 and P = 0·003, respectively). Carbohydrate oxidation was lower by 5·5 % during the low-GI trials compared with the high-GI trials at the start of the first exercise session (P < 0·05). Blood lactate was significantly higher (6·1 v. 2·6 mmol/l; P = 0·019) and blood glucose significantly lower (4·8 v. 5·4 mmol/l; P = 0·039) at the end of the second exercise session during the high-GI trial compared with the low-GI trial. Sprint distance was not significantly different between conditions. A low-GI meal improved the metabolic profile before and during extended high-intensity intermittent exercise, but did not affect performance. Improvements in metabolic responses when consuming low-GI meals before exercise may be beneficial to the long-term health of athletes.
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324
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Ranchordas MK. Nutrition for adventure racing. Sports Med 2012. [PMID: 23006142 DOI: 10.2165/11635130-000000000-00000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Adventure racing requires competitors to perform various disciplines ranging from, but not limited to, mountain biking, running, kayaking, climbing, mountaineering, flat- and white-water boating and orienteering over a rugged, often remote and wilderness terrain. Races can vary from 6 hours to expedition-length events that can last up to 10-consecutive days or more. The purpose of this article is to provide evidence-based nutritional recommendations for adventure racing competitors. Energy expenditures of 365-750 kcal/hour have been reported with total energy expenditures of 18 000-80 000 kcal required to complete adventure races, and large negative energy balances during competitions have been reported. Nutrition, therefore, plays a major role in the successful completion of such ultra-endurance events. Conducting research in these events is challenging and the limited studies investigating dietary surveys and nutritional status of adventure racers indicate that competitors do not meet nutrition recommendations for ultra-endurance exercise. Carbohydrate intakes of 7-12 g/kg are needed during periods of prolonged training to meet requirements and replenish glycogen stores. Protein intakes of 1.4-1.7 g/kg are recommended to build and repair tissue. Adequate replacement of fluid and electrolytes are crucial, particularly during extreme temperatures; however, sweat rates can vary greatly between competitors. There is considerable evidence to support the use of sports drinks, gels and bars, as they are a convenient and portable source of carbohydrate that can be consumed during exercise, in training and in competition. Similarly, protein and amino acid supplements can be useful to help meet periods of increased protein requirements. Caffeine can be used as an ergogenic aid to help competitors stay awake during prolonged periods, enhance glycogen resynthesis and enhance endurance performance.
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Affiliation(s)
- Mayur K Ranchordas
- Sheffield Hallam University, Academy of Sport and Physical Activity, Collegiate Crescent Campus, Sheffield, UK.
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325
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Rüst CA, Knechtle B, Knechtle P, Rosemann T. Comparison of anthropometric and training characteristics between recreational male marathoners and 24-hour ultramarathoners. Open Access J Sports Med 2012; 3:121-9. [PMID: 24198595 PMCID: PMC3781907 DOI: 10.2147/oajsm.s37389] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Of the anthropometry and training variables used to predict race performance in a 24-hour ultrarun, the personal best marathon time is the strongest predictor in recreational male 24-hour ultramarathoners. This finding raises the question of whether similarities exist between male recreational 24-hour ultramarathoners and male recreational marathoners. Methods The association between age, anthropometric variables (ie, body mass, body height, body mass index, percent body fat, skeletal muscle mass, limb circumference, and skinfold thickness at the pectoral, mid axillary, triceps, subscapular, abdominal, suprailiac, front thigh, and medial calf sites), previous experience and training characteristics (ie, volume, speed, and personal best time), and race time for 79 male recreational 24-hour ultramarathoners and 126 male recreational marathoners was investigated using bivariate and multivariate analysis. Results The 24-hour ultramarathoners were older (P < 0.05), had a lower circumference at both the upper arm (P < 0.05) and thigh (P < 0.01), and a lower skinfold thickness at the pectoral, axillary, and suprailiac sites (P < 0.05) compared with the marathoners. During training, the 24-hour ultramarathoners were running for more hours per week (P < 0.001) and completed more kilometers (P < 0.001), but were running slower (P < 0.01) compared with the marathoners. In the 24-hour ultramarathoners, neither anthropometric nor training variables were associated with kilometers completed in the race (P > 0.05). In the marathoners, percent body fat (P < 0.001) and running speed during training (P < 0.0001) were related to marathon race times. Conclusion In summary, differences in anthropometric and training predictor variables do exist between male recreational 24-hour ultramarathoners and male recreational marathoners for race performance.
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326
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Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males. Nutr Metab (Lond) 2012; 9:91. [PMID: 23067428 PMCID: PMC3514209 DOI: 10.1186/1743-7075-9-91] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/14/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. METHODS Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8), 4x20g every 3h (intermediate, INT; n=7), or 2x40g every 6h (BOLUS; n=8) after an acute bout of bilateral knee extension exercise (4x10 repetitions at 80% maximal strength). Whole-body protein turnover (Q), synthesis (S), breakdown (B), and net balance (NB) were measured throughout 12h of recovery by a bolus ingestion of [15N]glycine with urinary [15N]ammonia enrichment as the collected end-product. RESULTS PULSE Q rates were greater than BOLUS (~19%, P<0.05) with a trend towards being greater than INT (~9%, P=0.08). Rates of S were 32% and 19% greater and rates of B were 51% and 57% greater for PULSE as compared to INT and BOLUS, respectively (P<0.05), with no difference between INT and BOLUS. There were no statistical differences in NB between groups (P=0.23); however, magnitude-based inferential statistics revealed likely small (mean effect±90%CI; 0.59±0.87) and moderate (0.80±0.91) increases in NB for PULSE and INT compared to BOLUS and possible small increase (0.42±1.00) for INT vs. PULSE. CONCLUSION We conclude that the pattern of ingested protein, and not only the total daily amount, can impact whole-body protein metabolism. Individuals aiming to maximize NB would likely benefit from repeated ingestion of moderate amounts of protein (~20g) at regular intervals (~3h) throughout the day.
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327
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Bosse JD, Dixon BM. Dietary protein to maximize resistance training: a review and examination of protein spread and change theories. J Int Soc Sports Nutr 2012; 9:42. [PMID: 22958314 PMCID: PMC3518828 DOI: 10.1186/1550-2783-9-42] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/04/2012] [Indexed: 11/10/2022] Open
Abstract
An appreciable volume of human clinical data supports increased dietary protein for greater gains from resistance training, but not all findings are in agreement. We recently proposed "protein spread theory" and "protein change theory" in an effort to explain discrepancies in the response to increased dietary protein in weight management interventions. The present review aimed to extend "protein spread theory" and "protein change theory" to studies examining the effects of protein on resistance training induced muscle and strength gains. Protein spread theory proposed that there must have been a sufficient spread or % difference in g/kg/day protein intake between groups during a protein intervention to see muscle and strength differences. Protein change theory postulated that for the higher protein group, there must be a sufficient change from baseline g/kg/day protein intake to during study g/kg/day protein intake to see muscle and strength benefits. Seventeen studies met inclusion criteria. In studies where a higher protein intervention was deemed successful there was, on average, a 66.1% g/kg/day between group intake spread versus a 10.2% g/kg/day spread in studies where a higher protein diet was no more effective than control. The average change in habitual protein intake in studies showing higher protein to be more effective than control was +59.5% compared to +6.5% when additional protein was no more effective than control. The magnitudes of difference between the mean spreads and changes of the present review are similar to our previous review on these theories in a weight management context. Providing sufficient deviation from habitual intake appears to be an important factor in determining the success of additional protein in enhancing muscle and strength gains from resistance training. An increase in dietary protein favorably effects muscle and strength during resistance training.
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Affiliation(s)
- John D Bosse
- USANA Health Sciences, Inc, 3838 West Parkway Boulevard, Salt Lake City, UT, 84120, USA
- Division of Nutrition, University of Utah, 250 South 1850 East #214, Salt Lake City, UT, 84112, USA
| | - Brian M Dixon
- USANA Health Sciences, Inc, 3838 West Parkway Boulevard, Salt Lake City, UT, 84120, USA
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Gunzer W, Konrad M, Pail E. Exercise-induced immunodepression in endurance athletes and nutritional intervention with carbohydrate, protein and fat-what is possible, what is not? Nutrients 2012; 4:1187-1212. [PMID: 23112908 PMCID: PMC3475230 DOI: 10.3390/nu4091187] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 08/23/2012] [Accepted: 08/24/2012] [Indexed: 01/08/2023] Open
Abstract
Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI). The aim of this review is to provide a critical up-to-date review of existing evidence on the immunomodulatory potential of selected macronutrients and to evaluate their efficacy. The results of 66 placebo-controlled and/or crossover trials were compared and analysed. Among macronutrients, the most effective approach to maintain immune function in athletes is to consume ≥6% carbohydrate during prolonged exercise. Because inadequate nutrition affects almost all aspects of the immune system, a well-balanced diet is also important. Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent. Using a single nutrient may not be as effective as a mixture of several nutritional supplements. Due to limited research evidence, with the exception of carbohydrate, no explicit recommendations to reduce post-exercise URTI symptoms with single macronutrients can be derived.
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Affiliation(s)
| | - Manuela Konrad
- Author to whom correspondence should be addressed; ; Tel.: +43-316-5453-6762; Fax: +43-316-5453-6741
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329
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Storey A, Smith HK. Unique aspects of competitive weightlifting: performance, training and physiology. SPORTS MEDICINE (AUCKLAND, N.Z.) 2012. [PMID: 22873835 DOI: 10.2165/11633000-000000000-00000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Weightlifting is a dynamic strength and power sport in which two, multijoint, whole-body lifts are performed in competition; the snatch and clean and jerk. During the performance of these lifts, weightlifters have achieved some of the highest absolute and relative peak power outputs reported in the literature. The training structure of competitive weightlifters is characterized by the frequent use of high-intensity resistance exercise movements. Varied coaching and training philosophies currently exist around the world and further research is required to substantiate the best type of training programme for male and female weightlifters of various age groups. As competitive weightlifting is contested over eight male and seven female body weight categories, the anthropometric characteristics of the athletes widely ranges. The body compositions of weightlifters are similar to that of athletes of comparable body mass in other strength and power sports. However, the shorter height and limb lengths of weightlifters provide mechanical advantages when lifting heavy loads by reducing the mechanical torque and the vertical distance that the barbell must be displaced. Furthermore, the shorter body dimensions coincide with a greater mean skeletal muscle cross-sectional area that is advantageous to weightlifting performance. Weightlifting training induces a high metabolic cost. Although dietary records demonstrate that weightlifters typically meet their required daily energy intake, weightlifters have been shown to over consume protein and fat at the expense of adequate carbohydrate. The resulting macronutrient imbalance may not yield optimal performance gains. Cross-sectional data suggest that weightlifting training induces type IIX to IIA fibre-type transformation. Furthermore, weightlifters exhibit hypertrophy of type II fibres that is advantageous to weightlifting performance and maximal force production. As such, the isometric peak force and contractile rate of force development of weightlifters is ~15-20% and ~13-16% greater, respectively, than in other strength and power athletes. In addition, weightlifting training has been shown to reduce the typical sex-related difference in the expression of neuromuscular strength and power. However, this apparent sex-related difference appears to be augmented with increasing adult age demonstrating that women undergo a greater age-related decline in muscle shortening velocity and peak power when compared with men. Weightlifting training and competition has been shown to induce significant structural and functional adaptations of the cardiovascular system. The collective evidence shows that these adaptations are physiological as opposed to pathological. Finally, the acute exercise-induced testosterone, cortisol and growth hormone responses of weightlifters have similarities to that of following conventional strength and hypertrophy protocols involving large muscle mass exercises. The routine assessment of the basal testosterone : cortisol ratio may be beneficial when attempting to quantify the adaptive responses to weightlifting training. As competitive weightlifting is becoming increasingly popular around the world, further research addressing the physiological responses and adaptations of female weightlifters and younger (i.e. ≤17 years of age) and older (i.e. ≥35 years of age) weightlifters of both sexes is required.
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Affiliation(s)
- Adam Storey
- Department of Sport and Exercise Science, The University of Auckland, Auckland, New Zealand.
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330
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Liu Y, Lange R, Langanky J, Hamma T, Yang B, Steinacker JM. Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial. J Int Soc Sports Nutr 2012; 9:37. [PMID: 22857787 PMCID: PMC3467174 DOI: 10.1186/1550-2783-9-37] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 07/24/2012] [Indexed: 11/10/2022] Open
Abstract
Background Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is “exercise-induced hyperammonemia”. Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. Methods Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session). Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9), branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12) or isocaloric placebo (control group, n = 12) daily. Results The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ± 35, 390 ± 29 and 273 ± 47, P<0.05) than in the control group (92 ± 70, 381 ± 67 and 233 ± 43). The general stress and emotional exhaustion as assessed by the rest-stress-questionnaire-sport after the 3rd week of training increased significantly in the control group (P<0.05), but not in the KAS groups. Conclusions Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance by KAS is associated with effects on ammonia homeostasis requires further observation.
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Affiliation(s)
- Yuefei Liu
- Section of Sports and Rehabilitation Medicine, Department of Internal Medicine II, University of Ulm, Ulm, D-89070, Germany.
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331
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Abstract
It is recognised that regular physical activity and a high level of fitness are powerful predictors of positive health outcomes. There is a long and rich history of significant feats of human endurance with some, for example, the death of the first marathon runner, Pheidippides, associated with negative health outcomes. Early studies on endurance running used X-ray and interview techniques to evaluate competitors and comment on performance. Since then, comparatively few studies have looked at runners competing in distances longer than a marathon. Those that have, tend to show significant musculoskeletal injuries and a remarkable level of adaptation to this endurance load. The TransEurope Footrace Project followed ultra-endurance runners aiming to complete 4,500 Km of running in 64 days across Europe. This pioneering study will assess the impact of extreme endurance on human physiology; analysing musculoskeletal and other tissue/organ injuries, and the body's potential ability to adapt to extreme physiological stress. The results will be of interest not only to endurance runners, but to anyone interested in the limits of human performance. Please see related article: http://www.biomedcentral.com/1741-7015/10/78.
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332
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Gravina L, Ruiz F, Diaz E, Lekue JA, Badiola A, Irazusta J, Gil SM. Influence of nutrient intake on antioxidant capacity, muscle damage and white blood cell count in female soccer players. J Int Soc Sports Nutr 2012; 9:32. [PMID: 22812729 PMCID: PMC3409051 DOI: 10.1186/1550-2783-9-32] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 07/19/2012] [Indexed: 01/06/2023] Open
Abstract
Background Soccer is a form of exercise that induces inflammatory response, as well as an increase in free radicals potentially leading to muscle injury. Balanced nutritional intake provides important antioxidant vitamins, including vitamins A, C and E, which may assist in preventing exercise-related muscle damage. The purpose of the present study was to determine the effect of macro/micronutrient intake on markers of oxidative stress, muscle damage, inflammatory and immune response in female soccer players. Methods Twenty-eight female players belonging to two soccer teams of the same professional soccer club participated in this study after being informed about the aims and procedures and after delivering written consent. Each team completed an 8-day dietary record and played one competition match the same week. Participants were divided into two groups: the REC group (who complied with recommended intakes) and the NO-REC group (who were not compliant). Laboratory blood tests were carried out to determine hematological, electrolytic and hormonal variables, as well as to monitor markers of cell damage and oxidative stress. Blood samples were obtained 24 h before, immediately after and 18 h after official soccer matches. Student t-test or Mann–Whitney U-test was used to compare both groups throughout the match. Results At rest, we observed that the REC group had higher levels of total antioxidant status (TAS), glutathione peroxidase (GPx), and lower levels of creatine kinase (CK) and lactate dehydrogenase (LDH) in comparison to the NO-REC group. Immediately after the match, levels of TAS, GPx, superoxide dismutase (SOD), LDH and % lymphocytes were higher and the % of neutrophils were lower in the REC group compared to the NO-REC group. These differences were also maintained 18 h post-match, only for TAS and GPx. Conclusions Our data reveal an association between nutritional intake and muscle damage, oxidative stress, immunity and inflammation markers. The benefit of the intake of specific nutrients may contribute to preventing the undesirable physiological effects provoked by soccer matches.
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Affiliation(s)
- Leyre Gravina
- Department of Nursing I, School of Nursing, University of the Basque Country (UPV/EHU), B° Sarriena s/n, 48940, Leioa, Bizkaia, Spain.
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333
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Abstract
CONTEXT Time allowing, euhydration can be achieved in the vast majority of individuals by drinking and eating normal beverages and meals. Important to the competitive athlete is prevention and treatment of dehydration and exercise-associated muscle cramps, as they are linked to a decline in athletic performance. Intravenous (IV) prehydration and rehydration has been proposed as an ergogenic aid to achieve euhydration more effectively and efficiently. EVIDENCE ACQUISITION PubMed database was searched in November 2011 for all English-language articles related to IV utilization in sport using the keywords intravenous, fluid requirements, rehydration, hydration, athlete, sport, exercise, volume expansion, and performance. RESULTS Limited evidence exists for prehydration with IV fluids. Although anecdotal evidence does exist, at this time there are no high-level studies confirming that IV prehydration prevents dehydration or the onset of exercise-associated muscle cramps. Currently, there are no published studies describing IV fluid use during the course of an event, at intermission, or after the event as an ergogenic aid. CONCLUSION The use of IV fluid may be beneficial for a subset of fluid-sensitive athletes; this should be reserved for high-level athletes with strong histories of symptoms in well-monitored settings. Volume expanders may also be beneficial for some athletes. IV fluids and plasma binders are not allowed in World Anti-Doping Agency-governed competitions. Routine IV therapy cannot be recommended as best practice for the majority of athletes.
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334
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Rüst CA, Knechtle B, Knechtle P, Rosemann T. Similarities and differences in anthropometry and training between recreational male 100-km ultra-marathoners and marathoners. J Sports Sci 2012; 30:1249-57. [PMID: 22724447 DOI: 10.1080/02640414.2012.697182] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Several recent investigations showed that the best marathon time of an individual athlete is also a strong predictor variable for the race time in a 100-km ultra-marathon. We investigated similarities and differences in anthropometry and training characteristics between 166 100-km ultra-marathoners and 126 marathoners in recreational male athletes. The association of anthropometric variables and training characteristics with race time was assessed by using bi- and multi-variate analysis. Regarding anthropometry, the marathoners had a significantly lower calf circumference (P < 0.05) and a significantly thicker skinfold at pectoral (P < 0.01), axilla (P < 0.05), and suprailiacal sites (P < 0.05) compared to the ultra-marathoners. Considering training characteristics, the marathoners completed significantly fewer hours (P < 0.001) and significantly fewer kilometres (P < 0.001) during the week, but they were running significantly faster during training (P < 0.001). The multi-variate analysis showed that age (P < 0.0001), body mass (P = 0.011), and percent body fat (P = 0.019) were positively and weekly running kilometres (P < 0.0001) were negatively related to 100-km race times in the ultra-marathoners. In the marathoners, percent body fat (P = 0.002) was positively and speed in running training (P < 0.0001) was negatively associated with marathon race times. In conclusion, these data suggest that performance in both marathoners and 100-km ultra-marathoners is inversely related to body fat. Moreover, marathoners rely more on speed in running during training whereas ultra-marathoners rely on volume in running training.
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Affiliation(s)
- Christoph Alexander Rüst
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland
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335
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Too BW, Cicai S, Hockett KR, Applegate E, Davis BA, Casazza GA. Natural versus commercial carbohydrate supplementation and endurance running performance. J Int Soc Sports Nutr 2012; 9:27. [PMID: 22704463 PMCID: PMC3464793 DOI: 10.1186/1550-2783-9-27] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 06/15/2012] [Indexed: 11/15/2022] Open
Abstract
Background We examined the metabolic, performance and gastrointestinal (GI) effects of supplementation with a natural food product (raisins) compared to a commercial product (sport chews). Methods Eleven male (29.3 ± 7.9 yrs; mean and SD) runners completed three randomized trials (raisins, chews and water only) separated by seven days. Each trial consisted of 80-min (75%VO2max) treadmill running followed by a 5-km time trial (TT). Heart rate (HR), respiratory exchange ratio (RER), blood lactate, serum free fatty acids (FFA), glycerol and insulin, plasma glucose and creatine kinase, GI symptoms and rating of perceived exertion (RPE) were recorded every 20-min. We employed a within-subject two-way analysis of variance (ANOVA) for repeated measures with a Fisher’s post hoc analysis to determine significant differences. Results VO2, HR, lactate, glycerol and RPE did not differ due to treatment. Average plasma glucose was maintained at resting levels (5.3 ± 0.4 mmol·L-1) during the sub-maximal exercise bout (5.9 ± 0.6, 5.7 ± 0.6 and 5.5 ± 0.5 mmol·L-1 for chews, raisins and water respectively), and was significantly higher with chews than water only. RER and % of non-protein macronutrient oxidation derived from carbohydrate was highest with chews, followed by raisins and water was the lowest (74.4 ± 6.4, 70.0 ± 7.0 and 65.1 ± 8.7% for chews, raisins and water respectively) during the sub-maximal exercise period. Serum FFA was higher in the water treatment versus both raisins and chews at 80 min of sub-maximal exercise. Serum insulin was higher with the chews than both raisins and water (5.1 ± 2.0, 3.1 ± 0.8, 1.9 ± 0.6 uU·ml-1 for chews, raisins and water respectively). Plasma creatine kinase, corrected for baseline values, for the last 40 min of the sub-maximal exercise bout, was higher with raisins compared to other treatments. The TT was faster for both carbohydrate supplements (20.6 ± 2.6, 20.7 ± 2.5, 21.6 ± 2.7 min for raisin, chews and water respectively). GI disturbance was mild for all treatments. Conclusion Raisins and chews promoted higher carbohydrate oxidation and improved running performance compared to water only. Running performance was similar between the raisins and chews, with no significant GI differences.
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Affiliation(s)
- Brandon W Too
- Sports Performance Laboratory, University of California, Davis, Medical Center Sports Medicine Program, Sacramento, CA, USA.
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336
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Poortmans JR, Carpentier A, Pereira-Lancha LO, Lancha A. Protein turnover, amino acid requirements and recommendations for athletes and active populations. Braz J Med Biol Res 2012; 45:875-90. [PMID: 22666780 PMCID: PMC3854183 DOI: 10.1590/s0100-879x2012007500096] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/25/2012] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers (13C-lysine, 15N-glycine, 2H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg−1·day−1 compared to 0.8 g·kg−1·day−1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.
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Affiliation(s)
- J R Poortmans
- Laboratory for Biometry and Sport Nutrition, Faculty of Motor Sciences, Free University of Brussels, Brussels, Belgium
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337
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Shephard RJ. The impact of Ramadan observance upon athletic performance. Nutrients 2012; 4:491-505. [PMID: 22822448 PMCID: PMC3397348 DOI: 10.3390/nu4060491] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 05/18/2012] [Accepted: 05/30/2012] [Indexed: 11/16/2022] Open
Abstract
Ramadan observance requires a total abstention from food and drink from sunrise to sunset for a period of one month. Such intermittent fasting has only minor effects upon the overall nutrition and physiological responses of the general sedentary population. Larger meals are consumed at night and in the early morning. Body mass usually remains unchanged, the total energy intake remains roughly constant, and there is little alteration in the relative consumption of protein, fats and carbohydrates. However, Ramadan observance may be of greater consequence for the training and performance of the competitive athlete, particularly when the festival is celebrated in the hotter part of the year and daylight hours are long, as is the case for the 2012 Summer Olympic Games in London, England. The normal sleeping time then tends to be shortened, and blood sugar and tissue hydration decrease progressively throughout the hours of daylight. Some limitation of anaerobic effort, endurance performance and muscle strength might be anticipated from the decrease in muscle glycogen and body fluid reserves, and a reduced blood glucose may cause a depressed mood state, an increased perception of effort, and poorer team work. This review considers empirical data on the extent of such changes, and their likely effect upon anaerobic, aerobic and muscular performance, suggesting potential nutritional and behavioral tactics for minimizing such effects in the Muslim competitor.
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Affiliation(s)
- Roy J Shephard
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada.
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338
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Pfeiffer B, Stellingwerff T, Hodgson AB, Randell R, Pöttgen K, Res P, Jeukendrup AE. Nutritional intake and gastrointestinal problems during competitive endurance events. Med Sci Sports Exerc 2012; 44:344-51. [PMID: 21775906 DOI: 10.1249/mss.0b013e31822dc809] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED There is little information about the actual nutrition and fluid intake habits and gastrointestinal (GI) symptoms of athletes during endurance events. PURPOSE This study aimed to quantify and characterize energy, nutrient, and fluid intakes during endurance competitions and investigate associations with GI symptoms. METHOD A total of 221 endurance athletes (male and female) were recruited from two Ironman triathlons (IM Hawaii and IM GER), a half-Ironman (IM 70.3), a MARATHON, a 100/150-km CYCLE race. Professional cyclists (PRO) were investigated during stage racing. A standardized postrace questionnaire quantified nutrient intake and assessed 12 GI symptoms on a scale from 0 (no problem) to 9 (worst it has ever been) in each competition. RESULTS Mean CHO intake rates were not significantly different between IM Hawaii, IM GER, and IM 70.3 (62 ± 26, 71 ± 25, and 65 ± 25 g·h(-1), respectively), but lower mean CHO intake rates were reported during CYCLE (53 ± 22 g·h(-1), P = 0.044) and MARATHON (35 ± 26 g·h(-1), P < 0.01). Prevalence of serious GI symptoms was highest during the IM races (∼31%, P = 0.001) compared with IM 70.3 (14%), CYCLE (4%), MARATHON (4%), and PRO (7%) and correlated to a history of GI problems. In all data sets, scores for upper and lower GI symptoms correlated with a reported history of GI distress (r = 0.37 and r = 0.51, respectively, P < 0.001). Total CHO intake rates were positively correlated with nausea and flatulence but were negatively correlated with finishing time during both IM (r = -0.55 and r = -0.48, P < 0.001). CONCLUSIONS The present study demonstrates that CHO intake rates vary greatly between events and individual athletes (6-136 g·h(-1)). High CHO intake during exercise was related not only to increased scores for nausea and flatulence but also to better performance during IM races.
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Affiliation(s)
- Beate Pfeiffer
- School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
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339
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Allen PJ. Creatine metabolism and psychiatric disorders: Does creatine supplementation have therapeutic value? Neurosci Biobehav Rev 2012; 36:1442-62. [PMID: 22465051 PMCID: PMC3340488 DOI: 10.1016/j.neubiorev.2012.03.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 03/07/2012] [Accepted: 03/14/2012] [Indexed: 12/12/2022]
Abstract
Athletes, body builders, and military personnel use dietary creatine as an ergogenic aid to boost physical performance in sports involving short bursts of high-intensity muscle activity. Lesser known is the essential role creatine, a natural regulator of energy homeostasis, plays in brain function and development. Creatine supplementation has shown promise as a safe, effective, and tolerable adjunct to medication for the treatment of brain-related disorders linked with dysfunctional energy metabolism, such as Huntington's Disease and Parkinson's Disease. Impairments in creatine metabolism have also been implicated in the pathogenesis of psychiatric disorders, leaving clinicians, researchers and patients alike wondering if dietary creatine has therapeutic value for treating mental illness. The present review summarizes the neurobiology of the creatine-phosphocreatine circuit and its relation to psychological stress, schizophrenia, mood and anxiety disorders. While present knowledge of the role of creatine in cognitive and emotional processing is in its infancy, further research on this endogenous metabolite has the potential to advance our understanding of the biological bases of psychopathology and improve current therapeutic strategies.
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Affiliation(s)
- Patricia J Allen
- Department of Psychology, Tufts University, Psychology Building, 490 Boston Ave., Medford, MA 02155, USA.
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340
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Park SG, Bae YJ, Lee YS, Kim BJ. Effects of rehydration fluid temperature and composition on body weight retention upon voluntary drinking following exercise-induced dehydration. Nutr Res Pract 2012; 6:126-31. [PMID: 22586501 PMCID: PMC3349034 DOI: 10.4162/nrp.2012.6.2.126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 01/25/2012] [Accepted: 02/01/2012] [Indexed: 11/04/2022] Open
Abstract
The purpose of this study was to determine the effects of beverage temperature and composition on weight retention and fluid balance upon voluntary drinking following exercise induced-dehydration. Eight men who were not acclimated to heat participated in four randomly ordered testing sessions. In each session, the subjects ran on a treadmill in a chamber maintained at 37℃ without being supplied fluids until 2% body weight reduction was reached. After termination of exercise, they recovered for 90 min under ambient air conditions and received one of the following four test beverages: 10℃ water (10W), 10℃ sports drink (10S), 26℃ water (26W), and 26℃ sports drink (26S). They consumed the beverages ad libitum. The volume of beverage consumed and body weight were measured at 30, 60, and 90 min post-recovery. Blood samples were taken before and immediately after exercise as well as at the end of recovery in order to measure plasma parameters and electrolyte concentrations. We found that mean body weight decreased by 1.8-2.0% following exercise. No differences in mean arterial pressure, plasma volume, plasma osmolality, and blood electrolytes were observed among the conditions. Total beverage volumes consumed were 1,164 ± 388, 1,505 ± 614, 948 ± 297, and 1,239 ± 401 ml for 10W, 10S, 26W, and 26S respectively (P > 0.05). Weight retention at the end of recovery from dehydration was highest in 10S (1.3 ± 0.7 kg) compared to 10W (0.4 ± 0.5 kg), 26W (0.4 ± 0.4 kg), and (0.6 ± 0.4 kg) (P < 0.005). Based on these results, carbohydrate/electrolyte-containing beverages at cool temperature were the most favorable for consumption and weight retention compared to plain water and moderate temperature beverages.
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Affiliation(s)
- Sung Geon Park
- Exercise Physiology Laboratory, Kookmin University, Jeongneung-ro 77, Seongbuk-gu, Seoul 136-705, Korea
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341
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Rowlands DS, Swift M, Ros M, Green JG. Composite versus single transportable carbohydrate solution enhances race and laboratory cycling performance. Appl Physiol Nutr Metab 2012; 37:425-36. [PMID: 22468766 DOI: 10.1139/h2012-013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When ingested at high rates (1.8-2.4 g·min(-1)) in concentrated solutions, carbohydrates absorbed by multiple (e.g., fructose and glucose) vs. single intestinal transporters can increase exogenous carbohydrate oxidation and endurance performance, but their effect when ingested at lower, more realistic, rates during intermittent high-intensity endurance competition and trials is unknown. Trained cyclists participated in two independent randomized crossover investigations comprising mountain-bike races (average 141 min; n = 10) and laboratory trials (94-min high-intensity intervals followed by 10 maximal sprints; n = 16). Solutions ingested during exercise contained electrolytes and fructose + maltodextrin or glucose + maltodextrin in 1:2 ratio ingested, on average, at 1.2 g carbohydrate·kg(-1)·h(-1). Exertion, muscle fatigue, and gastrointestinal discomfort were recorded. Data were analysed using mixed models with gastrointestinal discomfort as a mechanism covariate; inferences were made against substantiveness thresholds (1.2% for performance) and standardized difference. The fructose-maltodextrin solution substantially reduced race time (-1.8%; 90% confidence interval = ±1.8%) and abdominal cramps (-8.1 on a 0-100 scale; ±6.6). After accounting for gastrointestinal discomfort, the effect of the fructose-maltodextrin solution on lap time was reduced (-1.1%; ±2.4%), suggesting that gastrointestinal discomfort explained part of the effect of fructose-maltodextrin on performance. In the laboratory, mean sprint power was enhanced (1.4%; ±0.8%) with fructose-maltodextrin, but the effect on peak power was unclear (0.7%; ±1.5%). Adjusting out gastrointestinal discomfort augmented the fructose-maltodextrin effect on mean (2.6%; ±1.9%) and peak (2.5%; ±3.0%) power. Ingestion of multiple transportable vs. single transportable carbohydrates enhanced mountain-bike race and high-intensity laboratory cycling performance, with inconsistent but not irreconcilable effects of gut discomfort as a possible mediating mechanism.
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Affiliation(s)
- David S Rowlands
- Institute of Food, Nutrition, and Human Health, Massey University, Wellington, New Zealand.
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Costa RJS, Crockford MJ, Moore JP, Walsh NP. Heat acclimation responses of an ultra-endurance running group preparing for hot desert-based competition. Eur J Sport Sci 2012; 14 Suppl 1:S131-41. [PMID: 24444197 DOI: 10.1080/17461391.2012.660506] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Heat acclimation induces adaptations that improve exercise tolerance in hot conditions. Here we report novel findings into the effects of ultra-marathon specific exercise load in increasing hot ambient conditions on indices of heat acclimation. Six male ultra-endurance runners completed a standard pre-acclimation protocol at 20°C ambient temperature (T amb), followed by a heat acclimation protocol consisting of six 2 h running exercise-heat exposures (EH) at 60% VO2max on a motorised treadmill in an environmental chamber. Three EH were performed at 30°C T amb, followed by another three EH at 35°C T amb. EH were separated by 48 h within T amb and 72 h between T amb. Nude body mass (NBM), blood and urine samples were collected pre-exercise; while NBM and urine were collected post-exercise. Rectal temperature (T re), heart rate (HR), thermal comfort rating (TCR) and rating of perceived exertion were measured pre-exercise and monitored every 5 min during exercise. Water was provided ad libitum during exercise. Data were analysed using a repeated measures and one-way analysis of variance (ANOVA), with post hoc Tukey's HSD. Significance was accepted as P< 0.05. Overall mean T re was significantly lower during 30°C EH3 and 35°C EH3 compared with their respective EH1 (-0.20 and-0.23°C, respectively; P<0.05). Similarly, overall mean HR was significantly lower during 30°C EH3 and 35°C EH3 compared with their respective EH1 (8 and 7 bpm respectively; P<0.05). A significant decrease in overall mean TCR was observed during 35°C EH3, compared with 35°C EH1 (P< 0.05). Significant increases in resting pre-exercise plasma volume (estimated from Hb and Hct) were observed by 30°C EH3 (7.9%; P< 0.05). Thereafter, plasma volume remained above baseline throughout the experimental protocol. Two EH of 2 h at 60% VO2max at 30°C T amb was sufficient to initiate heat acclimation in all ultra-endurance runners. Further, heat acclimation responses occurred with increasing EH to 35°C T amb. Preventing exertional heat illnesses and optimising performance outcomes in ultra-endurance runners may occur with exposure to at least 2 h of exercise-heat stress on at least two occasions in the days leading up to multi-stage ultra-marathon competition in the heat.
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Affiliation(s)
- Ricardo J S Costa
- a Department of Health Professions , Coventry University , Coventry , UK
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Cosio-Lima LM, Desai B, Stelzer JW, Schuler PB. Effects of 4:1 carbohydrate/protein solution versus a carbohydrate-alone solution on IL-6, TNF-α, and cortisol during prolonged cycling in hot environmental conditions. Open Access J Sports Med 2012; 3:21-6. [PMID: 24198583 PMCID: PMC3781895 DOI: 10.2147/oajsm.s28176] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Intense or prolonged exercise and/or heat stress might affect the immune system creating a response similar to trauma or inflammation, resulting in an increase in the susceptibility to viral infections. For example, during prolonged exercise, inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and the stress hormone cortisol are produced and released. Although there have been several studies examining the effects of nutritional supplementation on cytokine release in elite athletes, few studies have investigated the effects of different energy drinks during exercise in adverse environmental conditions. Therefore, the purpose of this study was to compare plasma levels of inflammatory cytokines TNF-α and IL-6, and the stress hormone cortisol, during prolonged cycling under hot environmental conditions while ingesting fluid that contains a ratio of 4:1 carbohydrates and protein (4:1 CHO/PRO) versus a carbohydrate-only drink (CHO). Methods Six male cyclists (aged 27 ± 8 years; weight 75.5 ± 3.4 kg; VO2max = 66 ± 2.7 mL/kg/min, mean ± standard error) rode on a stationary ergometer on two separate sessions for 2.5 hours at 75% VO2max in an environmental chamber set at 35°C and 60% relative humidity. During the first session the cyclists were given 4 mL/kg body weight of a 6% carbohydrate solution every 15 minutes. During the second session they were given 4 mL/kg body weight of a 4:1 carbohydrate/protein drink every 15 minutes. Subjects were not aware of which drink they were given in each trial. Blood samples were taken pre-, immediately post-, and 12 hours post-exercise. SPSS (IBM Corp, Armonk, NY) was utilized to analyze data through repeated measures analysis of variance. Results No significant main effect was observed between treatments in either cortisol (P = 0.97), IL-6 (P = 0.64), or TNF-α (P = 0.37) responses. Total cortisol concentrations were significantly elevated (P < 0.05) immediately post-exercise, and from pre- to 12 hours post-exercise with both the 4:1 CHO/PRO and the CHO-alone solutions. TNF-α concentrations were only significantly (P = 0.045) elevated post-exercise with the CHO-alone solution. A significant (P < 0.05) elevation of IL-6 was seen immediately post-exercise and 12 hours post-exercise with both the CHO-alone and 4:1 CHO/PRO solutions. Conclusions Consuming a 4:1 CHO/PRO solution during prolonged cycling under hot environmental conditions has comparable effects on inflammatory cytokines to drinking a CHO-alone solution.
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Affiliation(s)
- Ludmila M Cosio-Lima
- Department of Health, Leisure, and Exercise Science, University of West Florida, Pensacola, FL, USA
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Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. Eur J Sport Sci 2012; 13:295-303. [PMID: 23679146 DOI: 10.1080/17461391.2011.643923] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Strength training and positive energy intake are the most important factors related to lean body mass (LBM) gain. Most studies investigating weight-gain interventions are based recreationally active subjects and less is known about optimal weight-gain protocols in elite athletes. The purpose of this study was to evaluate the effect of nutritional guidance in an 8- to 12-week weight-gain period in elite athletes. Thirty-nine elite athletes were randomised to either a 'nutritional counseling group' (NCG, n=21, 19.1±2.9 years, 70.9±8.9 kg) or 'ad libitum group' (ALG, n=18, 19.6±2.7 years, 75.0±5.9 kg). All athletes continued their sport-specific training which included an additional four strength-training sessions per week. NCG followed a meal plan providing a positive energy balance, while the ALG athletes had an ad libitum energy intake. Body weight (BW), body composition, one repetition maximum (1RM), 40 m sprint and counter movement jump (CMJ) were measured pre- and post-intervention. Energy intake was higher in the NCG than in the ALG (3585±601 vs. 2964±884 kcal) and consequently BW increased more in NCG than in ALG (3.9±0.6% vs. 1.5±0.4%). Fat mass (FM) increased more in NCG than in ALG (15±4 vs. 3±3%), but gain in LBM was not different between groups. All 1RM results improved in both groups (6-12%), whereas 40 m sprint and CMJ remained unchanged, except for a significant decrease in 40 m sprint for the athletes in NCG. Athletes with nutritional guidance increased BW more, however, excess energy intake in a weight-gain protocol should be considered carefully due to undesirable increases in body fat.
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Affiliation(s)
- Ina Garthe
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway.
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345
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Pasiakos SM, Karl JP, Lutz LJ, Murphy NE, Margolis LM, Rood JC, Cable SJ, Williams KW, Young AJ, McClung JP. Cardiometabolic risk in US Army recruits and the effects of basic combat training. PLoS One 2012; 7:e31222. [PMID: 22384004 PMCID: PMC3285625 DOI: 10.1371/journal.pone.0031222] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 01/04/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Cardiometabolic disease risk in US military recruits and the effects of military training have not been determined. This study examined lifestyle factors and biomarkers associated with cardiometabolic risk in US Army recruits (209; 118 male, 91 female, 23 ± 5 yr) before, during, and after basic combat training (BCT). METHODOLOGY/PRINCIPAL FINDINGS Anthropometrics; fasting total (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol; triglycerides (TG); glucose; and insulin were measured at baseline and every 3 wks during the 10 wk BCT course. At baseline, 14% of recruits were obese (BMI>30 kg/m(2)), 27% were cigarette smokers, 37% were sedentary, and 34% reported a family history of cardiometabolic disease. TC was above recommended levels in 8%, LDL in 39%, TG in 5%, and glucose in 8% of recruits, and HDL was below recommended levels in 33% of recruits at baseline. By week 9, TC decreased 8%, LDL 10%, TG 13%, glucose 6% and homeostasis model assessment of insulin resistance (HOMA-IR) 40% in men (P<0.05). In women, TC, LDL, glucose and HOMA-IR were decreased from baseline at weeks 3 and 6 (P<0.05), but were not different from baseline levels at week 9. During BCT, body weight declined in men but not women, while body fat percentage declined in both men and women (P<0.05). CONCLUSIONS/SIGNIFICANCE At the start of military service, the prevalence of cardiometabolic risk in US military recruits is comparable to that reported in similar, college-aged populations. Military training appears to be an effective strategy that may mitigate risk in young people through improvements in lipid profiles and glycemic control.
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Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - J. Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - Laura J. Lutz
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - Nancy E. Murphy
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - Lee M. Margolis
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - Jennifer C. Rood
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Sonya J. Cable
- Directorate of Basic Combat Training, Fort Jackson, South Carolina, United States of America
| | - Kelly W. Williams
- Directorate of Basic Combat Training, Fort Jackson, South Carolina, United States of America
| | - Andrew J. Young
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
| | - James P. McClung
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States of America
- * E-mail:
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346
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Drenowatz C, Eisenmann JC, Carlson JJ, Pfeiffer KA, Pivarnik JM. Energy expenditure and dietary intake during high-volume and low-volume training periods among male endurance athletes. Appl Physiol Nutr Metab 2012; 37:199-205. [PMID: 22360344 DOI: 10.1139/h11-155] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The primary purpose of this study was to examine dietary intake in endurance-trained athletes during a week of high-volume and a week of low-volume training while measuring exercise energy expenditure (EEE), resting metabolic rate (RMR), and nonexercise activity thermogenesis (NEAT). In addition, compliance with current American College of Sports Medicine/American Dietetic Association nutrition and performance recommendations for macronutrients was evaluated. Energy expenditure and dietary intake were measured in 15 male endurance athletes during 2 nonconsecutive weeks resembling a high-volume and a low-volume training period. Anthropometric measurements were taken and percentage body fat was determined at the beginning and end of each week of training. Total daily energy expenditure (TDEE) was calculated by summing RMR, NEAT, and EEE. Dietary intake was assessed with an online food-frequency questionnaire completed at the end of each week of data collection. Despite significant differences between TDEE and energy intake, no difference in body composition between the beginning and end of either week of training was observed, suggesting underreporting of caloric intake. Further, no changes in total caloric intake or macronutrient intake occurred even though TDEE increased significantly during the high-volume training. Reported carbohydrate intake (4.5 g·kg(-1)) and fiber intake (25 g·day(-1)) were below recommendations, whereas fat intake (1.3 g·kg(-1)) was slightly above recommendations. In summary, no short-term dietary adjustments occurred in response to differences in training regimen. Because these athletes were generally consuming a Western diet, they may have required some support to achieve desirable intakes for health and performance.
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Affiliation(s)
- Clemens Drenowatz
- Department of Kinesiology, Michigan State University, East Lansing, MI 48824, USA.
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347
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A critical review of recommendations to increase dietary protein requirements in the habitually active. Nutr Res Rev 2012; 25:142-9. [PMID: 22340626 DOI: 10.1017/s0954422412000030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Some scientists and professional organisations have called for an increase in dietary protein for those who reach a threshold level of exercise, i.e. endurance athletes. But there are individual scientists who question this recommendation. Limitations in the procedures used to justify changing the recommended daily allowance (RDA) are at issue. N balance has been used to justify this increase; but it is limiting even when measured in a well-controlled clinical research centre. Experimental shortcomings are only exacerbated when performed in a sports or exercise field setting. Another laboratory method used to justify this increase, the isotope infusion procedure, has methodological problems as well. Stable isotope infusion data collected during and after exercise cannot account for fed-state gains that counterbalance those exercise losses over a 24 h dietary period. The present review concludes that an adaptive metabolic demand model may be needed to accurately study the protein health of the active individual.
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348
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Bescós R, Rodríguez FA, Iglesias X, Knechtle B, Benítez A, Marina M, Padullés JM, Torrado P, Vazquez J, Rosemann T. Nutritional behavior of cyclists during a 24-hour team relay race: a field study report. J Int Soc Sports Nutr 2012; 9:3. [PMID: 22309475 PMCID: PMC3287968 DOI: 10.1186/1550-2783-9-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 02/06/2012] [Indexed: 11/10/2022] Open
Abstract
Background Information about behavior of energy intake in ultra-endurance cyclists during a 24-hour team relay race is scarce. The nutritional strategy during such an event is an important factor which athletes should plan carefully before the race. The purpose of this study was to examine and compare the nutritional intake of ultra-endurance cyclists during a 24-hour team relay race with the current nutritional guidelines for endurance events. Additionally, we analyzed the relationship among the nutritional and performance variables. Methods Using a observational design, nutritional intake of eight males (mean ± SD: 36.7 ± 4.7 years; 71.6 ± 4.9 kg; 174.6 ± 7.3 cm; BMI 23.5 ± 0.5 kg/m2) participating in a 24-hour team relay cycling race was assessed. All food and fluid intake by athletes were weighed and recorded. Additionally, distance and speed performed by each rider were also recorded. Furthermore, before to the race, all subjects carried out an incremental exercise test to determine two heart rate-VO2 regression equations which were used to estimate the energy expenditure. Results The mean ingestion of macronutrients during the event was 943 ± 245 g (13.1 ± 4.0 g/kg) of carbohydrates, 174 ± 146 g (2.4 ± 1.9 g/kg) of proteins and 107 ± 56 g (1.5 ± 0.7 g/kg) of lipids, respectively. This amount of nutrients reported an average nutrient intake of 22.8 ± 8.9 MJ which were significantly lower compared with energy expenditure 42.9 ± 6.8 MJ (P = 0.012). Average fluid consumption corresponded to 10497 ± 2654 mL. Mean caffeine ingestion was 142 ± 76 mg. Additionally, there was no relationship between the main nutritional variables (i.e. energy intake, carbohydrates, proteins, fluids and caffeine ingestion) and the main performance variables (i.e. distance and speed). Conclusions A 24-hour hours cycling competition in a team relay format elicited high energy demands which were not compensated by energy intake of the athletes despite that dietary consumption of macronutrients did not differ to the nutritional guidelines for longer events.
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Affiliation(s)
- Raúl Bescós
- Institut Nacional d'Educació Física de Catalunya, Sports Sciences Research Group, Universitat de Barcelona, Spain.
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349
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Becker GF, Macedo RCO, Cunha GDS, Martins JB, Laitano O, Reischak-Oliveira A. Combined effects of aerobic exercise and high-carbohydrate meal on plasma acylated ghrelin and levels of hunger. Appl Physiol Nutr Metab 2012; 37:184-92. [DOI: 10.1139/h11-149] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study investigated the effect of an aerobic exercise bout associated with a high-carbohydrate (CHO) meal on plasma levels of acylated ghrelin and hunger sensation. Eight healthy males performed an exercise (ET) and a control (CT) trial. In ET, participants performed a 60-min cycling exercise (∼70% of maximal oxygen uptake) after consuming a high-CHO meal. In the CT, participants remained at rest throughout the whole period after consuming the high-CHO meal. Hunger sensation was assessed and blood samples were taken to determine the levels of acylated ghrelin, glucose, insulin, total cholesterol (TC), and triglycerides (TG). There was suppression of hunger after consuming the meal in ET and CT (p = 0.028 and p = 0.011, respectively). Hunger increased in CT in the period correspondent to the exercise session (p = 0.017) and remained suppressed in the ET. The area under the curve for acylated ghrelin showed that its levels were lower in the ET compared with CT in the period of the exercise plus the immediate period (1 h) postexercise (60.7 vs. 96.75 pg·mL–1·2 h–1, respectively; p = 0.04). Inverse correlations between acylated ghrelin levels and insulin, TC, and TG levels at different time points were observed. In conclusion, these findings suggest that 1 bout of aerobic exercise maintains the meal-induced suppression of hunger. The mechanism underlying this effect may involve the exercise-induced suppression of acylated ghrelin. These results implicate that the combination of a high-CHO meal and aerobic exercise may effectively improve appetite control and body weight management.
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Affiliation(s)
- Geórgia Franco Becker
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rodrigo Cauduro Oliveira Macedo
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Giovani dos Santos Cunha
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Jocelito Bijoldo Martins
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Orlando Laitano
- School of Physical Education, Federal University of Vale do São Francisco, Petrolina, PE, Brazil
| | - Alvaro Reischak-Oliveira
- Exercise Research Laboratory, School of Physical Education, Federal University of the State of Rio Grande do Sul, Porto Alegre, RS, Brazil
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