| 1. |
- Hansen, Mette, et al.
(författare)
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The female handball player
- 2018. - 1
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Ingår i: Handball Sports Medicine. - : Springer. - 9783662558911 - 9783662558928 ; , s. 553-570
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Bokkapitel (refereegranskat)
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| 2. |
- Fahrenholtz, I. L., et al.
(författare)
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Within-day energy deficiency and reproductive function in female endurance athletes
- 2018
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 28:3, s. 1139-1146
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to estimate and compare within-day energy balance (WDEB) in athletes with eumenorrhea and menstrual dysfunction (MD) with similar 24-hour energy availability/energy balance (EA/EB). Furthermore, to investigate whether within-day energy deficiency is associated with resting metabolic rate (RMR), body composition, S-cortisol, estradiol, T-3, and fasting blood glucose. We reanalyzed 7-day dietary intake and energy expenditure data in 25 elite endurance athletes with eumenorrhea (n=10) and MD (n=15) from a group of 45 subjects where those with disordered eating behaviors (n=11), MD not related to low EA (n=5), and low dietary record validity (n=4) had been excluded. Besides gynecological examination and disordered eating evaluation, the protocol included RMR measurement; assessment of body composition by dual-energy X-ray absorptiometry, blood plasma analysis, and calculation of WDEB in 1-hour intervals. Subjects with MD spent more hours in a catabolic state compared to eumenorrheic athletes; WDEB<0kcal: 23.0hour (20.8-23.4) vs 21.1hour (4.7-22.3), P=.048; WDEB<-300kcal: 21.8hour (17.8-22.4) vs 17.6hour (3.9-20.9), P=.043, although similar 24-hour EA: 35.6 (11.6) vs 41.3 (12.7) kcal/kg FFM/d, (P=.269), and EB: -659 (551) vs -313 (596) kcal/d, (P=.160). Hours with WDEB <0kcal and <-300kcal were inversely associated with RMRratio (r=-.487, P=.013, r=-.472, P=.018), and estradiol (r=-.433, P=.034, r=-.516, P=.009), and positively associated with cortisol (r=.442, P=.027, r=.463, P=.019). In conclusion, although similar 24-hour EA/EB, the reanalysis revealed that MD athletes spent more time in a catabolic state compared to eumenorrheic athletes. Within-day energy deficiency was associated with clinical markers of metabolic disturbances.
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| 3. |
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| 4. |
- Burke, Louise M, et al.
(författare)
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International Association of Athletics Federations Consensus Statement 2019 : Nutrition for Athletics.
- 2019
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 29:2, s. 73-84
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Tidskriftsartikel (refereegranskat)abstract
- The International Association of Athletics Federations recognizes the importance of nutritional practices in optimizing an Athlete's well-being and performance. Although Athletics encompasses a diverse range of track-and-field events with different performance determinants, there are common goals around nutritional support for adaptation to training, optimal performance for key events, and reducing the risk of injury and illness. Periodized guidelines can be provided for the appropriate type, amount, and timing of intake of food and fluids to promote optimal health and performance across different scenarios of training and competition. Some Athletes are at risk of relative energy deficiency in sport arising from a mismatch between energy intake and exercise energy expenditure. Competition nutrition strategies may involve pre-event, within-event, and between-event eating to address requirements for carbohydrate and fluid replacement. Although a "food first" policy should underpin an Athlete's nutrition plan, there may be occasions for the judicious use of medical supplements to address nutrient deficiencies or sports foods that help the athlete to meet nutritional goals when it is impractical to eat food. Evidence-based supplements include caffeine, bicarbonate, beta-alanine, nitrate, and creatine; however, their value is specific to the characteristics of the event. Special considerations are needed for travel, challenging environments (e.g., heat and altitude); special populations (e.g., females, young and masters athletes); and restricted dietary choice (e.g., vegetarian). Ideally, each Athlete should develop a personalized, periodized, and practical nutrition plan via collaboration with their coach and accredited sports nutrition experts, to optimize their performance.
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| 5. |
- Burke, Louise M., et al.
(författare)
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Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes
- 2018
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 28:4, s. 350-363
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Forskningsöversikt (refereegranskat)abstract
- The human body requires energy for numerous functions including, growth, thermogenesis, reproduction, cellular maintenance, and movement. In sports nutrition, energy availability (EA) is defined as the energy available to support these basic physiological functions and good health once the energy cost of exercise is deducted from energy intake (EI), relative to an athlete's fat-free mass (FFM). Low EA provides a unifying theory to link numerous disorders seen in both female and male athletes, described by the syndrome Relative Energy Deficiency in Sport, and related to restricted energy intake, excessive exercise or a combination of both. These outcomes are incurred in different dose-response patterns relative to the reduction in EA below a "healthy" level of similar to 45 kcal.kg FFM-1.day(-1). Although EA estimates are being used to guide and monitor athletic practices, as well as support a diagnosis of Relative Energy Deficiency in Sport, problems associated with the measurement and interpretation of EA in the field should be explored. These include the lack of a universal protocol for the calculation of EA, the resources needed to achieve estimates of each of the components of the equation, and the residual errors in these estimates. The lack of a clear definition of the value for EA that is considered "low" reflects problems around its measurement, as well as differences between individuals and individual components of "normal"/"healthy" function. Finally, further investigation of nutrition and exercise behavior including within-and between-day energy spread and dietary characteristics is warranted since it may directly contribute to low EA or its secondary problems.
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| 6. |
- Carr, Amelia, et al.
(författare)
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Nutritional Intake in Elite Cross-Country Skiers During Two Days of Training and Competition
- 2019
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - Birmingham : Human Kinetics. - 1526-484X .- 1543-2742. ; 29:3, s. 273-281
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the energy, macronutrient, and fluid intakes, as well as hydration status (urine specific gravity), in elite cross-country skiers during a typical day of training (Day 1) and a sprint skiing competition the following day (Day 2). A total of 31 (18 males and 13 females) national team skiers recorded their food and fluid intakes and urine specific gravity was measured on Days 1 and 2. In addition, the females completed the Low Energy Availability in Females Questionnaire to assess their risk of long-term energy deficiency. Energy intake for males was 65 ± 9 kcal/kg on Day 1 versus 58 ± 9 kcal/kg on Day 2 (p = .002) and for females was 57 ± 10 on Day 1 versus 55 ± 5 kcal/kg on Day 2 (p = .445). Carbohydrate intake recommendations of 10-12 g·kg-1·day-1 were not met by 89% of males and 92% of females. All males and females had a protein intake above the recommended 1.2-2.0 g/kg on both days and a postexercise protein intake above the recommended 0.3 g/kg. Of the females, 31% were classified as being at risk of long-term energy deficiency. In the morning of Day 1, 50% of males and 46% of females were dehydrated; on Day 2, this was the case for 56% of males and 38% of females. In conclusion, these data suggest that elite cross-country skiers ingested more protein and less carbohydrate than recommended and one third of the females were considered at risk of long-term energy deficiency. Furthermore, many of the athletes were dehydrated prior to training and competition.
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| 7. |
- Helge, E. Wulff, et al.
(författare)
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BMD in elite female triathletes is related to isokinetic peak torque without any association to sex hormone concentrations
- 2012
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Ingår i: Journal of Sports Medicine and Physical Fitness. - : Edizioni Minerva Medica. - 0022-4707 .- 1827-1928. ; 52:5, s. 489-500
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Tidskriftsartikel (refereegranskat)abstract
- Aim. Female endurance athletes suffering from low energy availability and reproductive hormonal disorders are at risk of low BMD. Muscle forces acting on bone may have a reverse site-specific effect. Therefore we wanted to test how BMD in female elite triathletes was associated to isokinetic peak torque (IPT) and reproductive hormone concentrations (RHC). A possible effect of oral contraceptives (OCON's) is taken into consideration. Methods. Eight female elite triathletes (training 8-24 hrs/wk) and seven sedentary controls, age 21-37 years, participated. Total body and regional BIVID (g.cm(-2)) were measured by DXA. IPT were measured during knee extension, and trunk extension and flexion (Nm). Serum RHC and biochemical bone markers were evaluated. Energy balance was estimated from 7-days training-and weighed food records. Results. Despite a high training volume, BMD in triathletes was not higher than in controls. In triathletes trunk flexion IPT, but not RHC, was a strong predictor of BMD in both total body and femur (0.70
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| 8. |
- Logue, Danielle M., et al.
(författare)
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Low Energy Availability in Athletes 2020 : An Updated Narrative Review of Prevalence, Risk, Within-Day Energy Balance, Knowledge and Impact of Sports Performance
- 2020
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 12:3, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Low energy availability (EA) underpins the female and male athlete triad and relative energy deficiency in sport (RED-S). The condition arises when insufficient calories are consumed to support exercise energy expenditure, resulting in compromised physiological processes, such as menstrual irregularities in active females. The health concerns associated with longstanding low EA include menstrual/libido, gastrointestinal and cardiovascular dysfunction and compromised bone health, all of which can contribute to impaired sporting performance. This narrative review provides an update of our previous review on the prevalence and risk of low EA, within-day energy deficiency, and the potential impact of low EA on performance. The methods to assess EA remain a challenge and contribute to the methodological difficulties in identifying "true" low EA. Screening female athletic groups using a validated screening tool such as the Low Energy Availability in Females Questionnaire (LEAF-Q) has shown promise in identifying endurance athletes at risk of low EA. Knowledge of RED-S and its potential implications for performance is low among coaches and athletes alike. Development of sport and gender-specific screening tools to identify adolescent and senior athletes in different sports at risk of RED-S is warranted. Education initiatives are required to raise awareness among coaches and athletes of the importance of appropriate dietary strategies to ensure that sufficient calories are consumed to support training.
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| 9. |
- Logue, Danielle M., et al.
(författare)
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Self-reported reproductive health of athletic and recreational active males in Ireland : potential health effects interfering with perfromance
- 2021
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Ingår i: European Journal of Sport Science. - : Taylor & Francis Group. - 1746-1391 .- 1536-7290. ; 21:2, s. 275-284
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The syndrome of Relative Energy Deficiency in Sport (RED-S) consensus statements recognise that male athletes might have impaired fertility in terms of the Exercise Hypogonodal Male Condition (ExHMC). Thus, the aims of this study were to (1) identify risk of ExHMC in active males in various sports and (2) determine if associations between risk of ExHMC and health problems interfering with training and competition exist. Methods: A questionnaire was distributed online (November 2018–January 2019) using questions derived from the “Androgen Deficiency in the Aging Male Questionnaire” (ADAM-Q) to assess risk of ExHMC. Additional questions were included to collect information on participant demographics, injury and illness history and dietary habits. Logistic regression analyses explored differences between groups. Results: Risk of ExHMC was identified in 23.3% (n = 185) of 794 questionnaire participants. Following multivariate analyses, risk of ExHMC was independently associated with a lower than normal sex drive rating within the last month (OR 7.62, 95%CI 4.99–11.63) and less than three morning erections per week within the last month (OR: 4.67, 95%CI 3.23–6.76). Risk of ExHMC was associated with 15–21 days absence from training or competition during the previous 6 months due to overload injuries in the univariate analysis (OR = 2.69, 95% CI = 1.24–5.84). Conclusion: Risk of ExHMC and associated symptoms in this heterogeneous sample may be indicative of RED-S. Confounding factors such as over-training, medication use, fatigue and psychological stress need to be considered. Identification of male athletes exhibiting physiological symptoms associated with RED-S requires more research.
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| 10. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Disordered Eating and Eating Disorders in Aquatic Sports
- 2014
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 24:4, s. 450-459
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Tidskriftsartikel (refereegranskat)abstract
- Disordered eating behavior (DE) and eating disorders (EDs) are of great concern because of their associations with physical and mental health risks and, in the case of athletes, impaired performance. The syndrome originally known as the Female Athlete Triad, which focused on the interaction of energy availability, reproductive function, and bone health in female athletes, has recently been expanded to recognize that Relative Energy Deficiency in Sport (RED-S) has a broader range of negative effects on body systems with functional impairments in both male and female athletes. Athletes in leanness-demanding sports have an increased risk for RED-S and for developing EDs/DE. Special risk factors in aquatic sports related to weight and body composition management include the wearing of skimpy and tight-fitting bathing suits, and in the case of diving and synchronized swimming, the involvement of subjective judgments of performance. The reported prevalence of DE and EDs in athletic populations, including athletes from aquatic sports, ranges from 18 to 45% in female athletes and from 0 to 28% in male athletes. To prevent EDs, aquatic athletes should practice healthy eating behavior at all periods of development pathway, and coaches and members of the athletes' health care team should be able to recognize early symptoms indicating risk for energy deficiency, DE, and EDs. Coaches and leaders must accept that DE/EDs can be a problem in aquatic disciplines and that openness regarding this challenge is important.
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| 11. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Energy availability and the female athlete triad in elite endurance athletes
- 2015
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 25:5, s. 610-622
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Tidskriftsartikel (refereegranskat)abstract
- The female athlete triad (Triad), links low energy availability (EA), with menstrual dysfunction (MD), and impaired bone health. The aims of this study were to examine associations between EA/MD and energy metabolism and the prevalence of Triad-associated conditions in endurance athletes. Forty women [26.2 +/- 5.5 years, body mass index (BMI) 20.6 +/- 2.0 kg/m(2), body fat 20.0 +/- 3.0%], exercising 11.4 +/- 4.5 h/week, were recruited from national teams and competitive clubs. Protocol included gynecological examination; assessment of bone health; indirect respiratory calorimetry; diet and exercise measured 7 days to assess EA; eating disorder (ED) examination; blood analysis. Subjects with low/reduced EA (< 45 kcal/kg FFM/day), had lower resting metabolic rate (RMR) compared with those with optimal EA [28.4 +/- 2.0 kcal/kg fat-free mass (FFM)/day vs 30.5 +/- 2.2 kcal/kg FFM/day, P < 0.01], as did subjects with MD compared with eumenorrheic subjects (28.6 +/- 2.4 kcal/kg FFM/day vs 30.2 +/- 1.8 kcal/kg FFM/day, P < 0.05). 63% had low/reduced EA, 25% ED, 60% MD, 45% impaired bone health, and 23% had all three Triad conditions. 53% had low RMR, 25% hypercholesterolemia, and 38% hypoglycemia. Conclusively, athletes with low/reduced EA and/or MD had lowered RMR. Triad-associated conditions were common in this group of athletes, despite a normal BMI range. The high prevalence of ED, MD, and impaired bone health emphasizes the importance of prevention, early detection, and treatment of energy deficiency.
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| 12. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Energy Availability in Athletics : Health, Performance, and Physique
- 2019
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 29:2, s. 152-164
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Forskningsöversikt (refereegranskat)abstract
- The reported prevalence of low energy availability (LEA) in female and male track and field athletes is between 18% and 58% with the highest prevalence among athletes in endurance and jump events. In male athletes, LEA may result in reduced testosterone levels and libido along with impaired training capacity. In female track and field athletes, functional hypothalamic amenorrhea as consequence of LEA has been reported among 60% of elite middle- and long-distance athletes and 23% among elite sprinters. Health concerns with functional hypothalamic amenorrhea include impaired bone health, elevated risk for bone stress injury, and cardiovascular disease. Furthermore, LEA negatively affects recovery, muscle mass, neuromuscular function, and increases the risk of injuries and illness that may affect performance negatively. LEA in track and field athletes may occur due to intentional alterations in body mass or body composition, appetite changes, time constraints, or disordered eating behavior. Long-term LEA causes metabolic and physiological adaptations to prevent further weight loss, and athletes may therefore be weight stable yet have impaired physiological function secondary to LEA. Achieving or maintaining a lower body mass or fat levels through long-term LEA may therefore result in impaired health and performance as proposed in the Relative Energy Deficiency in Sport model. Preventive educational programs and screening to identify athletes with LEA are important for early intervention to prevent long-term secondary health consequences. Treatment for athletes is primarily to increase energy availability and often requires a team approach including a sport physician, sports dietitian, physiologist, and psychologist.
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| 13. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Impact of Menstrual Function on Hormonal Response to Repeated Bouts of Intense Exercise
- 2019
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 10, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Strenous exercise stimulates the hypothalamic-pituitary (HP) axis in order to ensure homeostasis and promote anabolism. Furthermore, exercise stimulates a transient increase in the neurotrophin brain-derived neurotrophic factor (BDNF) suggested to mediate the anxiolytic effects of exercise. Athletes with secondary functional hypothalamic amenorrhea (FHA) have been reported to have lower BDNF, and a blunted HP axis response to exercise as athletes with overtraining syndrome. Aim: The aim of the study was to investigate the hormonal and BDNF responses to a two-bout maximal exercise protocol with four hours of recovery in between in FHA and eumenorrheic (EUM) athletes. Methods: Eumenorrheic (n = 16) and FHA (n = 14) endurance athletes were recruited from national teams and competitive clubs. Protocols included gynecological examination; body composition (DXA); 7-day assessment of energy availability; blood sampling pre and post the two exercises tests. Results: There were no differences between groups in hormonal responses to the first exercise bout. After the second exercise bout IGFBP-3 increased more in FHA compared with EUM athletes (2.1 +/- 0.5 vs. 0.6 +/- 0.6 mu g/L, p = 0.048). There were non-significant trends toward higher increase in IGF-1 (39.3 +/- 4.3 vs. 28.0 +/- 4.6 mu g/L, p = 0.074), BDNF (96.5 +/- 22.9 vs. 34.4 +/- 23.5 mu g/L, p = 0.058), GH to cortisol ratio (0.329 +/- 0.010 vs. 0.058 +/- 0.010, p = 0.082), and decrease in IGF-1 to IGFBP-3 ratio (-2.04 +/- 1.2 vs. 0.92 +/- 1.22, p = 0.081) in athletes with FHA compared with EUM athletes. Furthermore, there was a non-significant trend toward a higher increase in prolactin to cortisol ratio in EUM athletes compared with athletes with FHA (0.60 +/- 0.15 vs. 0.23 +/- 0.15, p = 0.071). No differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function were found. Conclusion: No major differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function could be detected.
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| 14. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Low-energy density and high fiber intake are dietary concerns in female endurance athletes
- 2016
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 26:9, s. 1060-1071
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Tidskriftsartikel (refereegranskat)abstract
- Low or reduced energy availability (LEA) is linked to functional hypothalamic oligomenorrhea/amenorrhea (FHA), which is frequently reported in weight-sensitive sports. This makes LEA a major nutritional concern for female athletes. The aim of this study was to describe dietary characteristics of athletes with LEA and/or FHA. Endurance athletes (n=45) were recruited from national teams and competitive clubs. Protocols included gynecological examination, body composition, eating disorder evaluation, and 7-day dietary intake and EA assessment. Athletes with disordered eating behavior/eating disorders (n=11), menstrual dysfunction other than FHA (n=5), and low dietary record validity (n=4) were excluded. Remaining subjects (n=25) were characterized by EA [optimal:45kcal (188kJ)/kg fat-free mass (FFM)/day (n=11), LEA:<45kcal (188kJ)/kg FFM/day (n=14)] and reproductive function [eumenorrhea (EUM; n=10), FHA (n=15)]. There was no difference in EA between FHA and EUM subjects. However, FHA and LEA subjects shared the same dietary characteristics of lower energy density (ED) [(P=0.012; P=0.020), respectively], and fat content [(P=0.047; P=0.027), respectively]. Furthermore, FHA subjects had a lower intake of carbohydrate-rich foods (P=0.019), higher fiber content (P<0.001), and drive for thinness score (P=0.003). Conclusively, low ED together with high fiber content may constitute targets for dietary intervention in order to prevent and treat LEA and FHA in female athletes.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Needleman, I, et al.
(författare)
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Nutrition and oral health in sport : time for action
- 2018
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Ingår i: British Journal of Sports Medicine. - : BMJ Publishing Group Ltd. - 0306-3674 .- 1473-0480. ; 52:23, s. 1483-1484
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 19. |
- Staal, Sarah, et al.
(författare)
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Low RMRratio as a Surrogate Marker for Energy Deficiency, the Choice of Predictive Equation Vital for Correctly Identifying Male and Female Ballet Dancers at Risk
- 2018
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 28:4, s. 412-418
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Tidskriftsartikel (refereegranskat)abstract
- Ballet dancers are reported to have an increased risk for energy deficiency with or without disordered eating behavior. A low ratio between measured ((m)) and predicted ((p)) resting metabolic rate (RMRratio < 0.90) is a recognized surrogate marker for energy deficiency. We aimed to evaluate the prevalence of suppressed RMR using different methods to calculate pRMR and to explore associations with additional markers of energy deficiency. Female (n = 20) and male (n = 20) professional ballet dancers, 19-35 years of age, were enrolled. mRMR was assessed by respiratory calorimetry (ventilated open hood). pRMR was determined using the Cunningham and Harris-Benedict equations, and different tissue compartments derived from whole-body dual-energy X-ray absorptiometry assessment. The protocol further included assessment of body composition and bone mineral density, blood pressure, disordered eating (Eating Disorder Inventory-3), and for females, the Low Energy Availability in Females Questionnaire. The prevalence of suppressed RMR was generally high but also clearly dependent on the method used to calculate pRMR, ranging from 25% to 80% in males and 35% to 100% in females. Five percent had low bone mineral density, whereas 10% had disordered eating and 25% had hypotension. Forty percent of females had elevated Low Energy Availability in Females Questionnaire score and 50% were underweight. Suppressed RMR was associated with elevated Low Energy Availability in Females Questionnaire score in females and with higher training volume in males. In conclusion, professional ballet dancers are at risk for energy deficiency. The number of identified dancers at risk varies greatly depending on the method used to predict RMR when using RMRratio as a marker for energy deficiency.
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| 20. |
- Stenqvist, Thomas Birkedal, et al.
(författare)
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Impact of a 4-Week Intensified Endurance Training Intervention on Markers of Relative Energy Deficiency in Sport (RED-S) and Performance Among Well-Trained Male Cyclists
- 2020
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Ingår i: Frontiers in Endocrinology. - : Frontiers Media S.A.. - 1664-2392. ; 11, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Cyclists often apply block periodization to high training volumes in meso- and macrocycles to optimize training adaptation and to prepare for competition. Body mass influences performance in many sports, including endurance disciplines, and conditions related to the syndrome Relative Energy Deficiency in Sports (RED-S) such as metabolic adaptations and premature osteoporosis have also been reported in male cyclists. This study aimed to determine how a 4-week mesocycle of intensified endurance training designed to increase performance, would affect markers of RED-S in well-trained male cyclists. Twenty-two participants (age: 33.5 +/- 6.6 years, height: 181.4 +/- 5.2 cm, weight: 76.5 +/- 7.4 kg, peak oxygen uptake (VO2peak): 63.5 +/- 6.6 mL center dot kg(-1)center dot min(-1)) were recruited and instructed to maintain their background training load and to follow a supervised training protocol consisting of three high-intensity interval training sessions per week with a work duration of 32 min per session. Protocols included pre- and postintervention assessment of resting metabolic rate (RMR) using a ventilated hood, body composition and bone health by dual-energy X-ray absorptiometry (DXA), blood samples, energy intake, and aerobic performance. The interval training increased participants' aerobic performance-peak power output [4.8%,p< 0.001], VO2peak[2.4%,p= 0.005], and functional threshold power [6.5%,p< 0.001] as well as total testosterone levels [8.1%,p= 0.011]-while no changes were observed in free testosterone [4.1%,p= 0.326]. Bodyweight, body composition, and energy intake were unchanged from pre- to post-test. Triiodothyronine (T-3) [4.8%,p= 0.008], absolute RMR [3.0%,p= 0.010], relative RMR [2.6%,p= 0.013], and RMRratio[3.3%,p= 0.011] decreased, and cortisol levels increased [12.9%,p= 0.021], while no change were observed in the total testosterone:cortisol ratio [1.6%,p= 0.789] or the free testosterone:cortisol (fT:cor) ratio [3.2%,p= 0.556]. A subgroup analysis of the five participants with the largest increase in fT:cor ratio, revealed a greater improvement in functional threshold power (9.5 vs. 2.5%,p= 0.037), and higher relative RMR (0.6 vs. -4.2%p= 0.039, respectively). In conclusion, 4 weeks of intensified endurance interval training increased the athletes' aerobic performance and testosterone levels. However, negative changes in markers related to RED-S, such as a reduction in RMR and T-3, and an increase in cortisol were observed. These results indicate the complexity involved, and that male athletes are at risk of developing clinical indications of RED-S even during a short 4-week endurance training mesocycle.
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| 21. |
- Tornberg, Åsa B.B., et al.
(författare)
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Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes
- 2017
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Ingår i: Medicine & Science in Sports & Exercise. - : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 49:12, s. 2478-2485
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Secondary functional hypothalamic amenorrhea (SFHA) is common among female athletes, especially in weight-sensitive sports. The aim of this study was to investigate the link between SFHA and neuromuscular performance in elite endurance athletes. Methods Sixteen eumenorrheic (EUM) and 14 SFHA athletes from national teams and competitive clubs participated. Methods included gynecological examination, body composition (dual-energy x-ray absorptiometry), resting metabolic rate and work efficiency, exercise capacity, knee muscular strength (KMS) and knee muscular endurance (KME), reaction time (RT), blood sampling performed on the third to fifth days of the menstrual cycle, and 7-d assessment of energy availability. Results SFHA athletes had lower estrogen (0.12 0.03 vs 0.17 +/- 0.09 nmolL(-1), P < 0.05), triiodothyronine (T-3) (1.4 +/- 0.2 vs 1.7 +/- 0.3 nmolL(-1), P < 0.01), and blood glucose (3.8 +/- 0.3 vs 4.4 +/- 0.3 mmolL(-1), P < 0.001) but higher cortisol levels (564 +/- 111 vs 400 +/- 140 nmolL(-1), P < 0.05) compared with EUM athletes. SFHA had a lower body weight (55.0 +/- 5.8 vs 60.6 +/- 7.1 kg, P < 0.05), but no difference in exercise capacity between groups was found (56.4 +/- 5.8 vs 54.0 +/- 6.3 mL O(2)min(-1)kg(-1)). RT was 7% longer, and KMS and KME were 11% and 20% lower compared with EUM athletes. RT was negatively associated with glucose (r = -0.40, P < 0.05), T-3 (r = -0.37, P < 0.05), and estrogen (r = -0.43, P < 0.05), but positively associated with cortisol (r = 0.38, P < 0.05). KMS and KME correlated with fat-free mass in the tested leg (FFMleg; r = 0.52, P < 0.001; r = 0.58, P < 0.001) but were negatively associated with cortisol (r = -0.42, P < 0.05; r = -0.59, P < 0.001). FFMleg explained the differences in KMS, while reproductive function and FFMleg independently explained the variability in KME. Conclusions We found lower neuromuscular performance among SFHA compared with EUM athletes linked to a lower FFMleg, glucose, estrogen, T-3, and elevated cortisol levels.
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| 22. |
- Torstveit, Monica Klungland, et al.
(författare)
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Within-Day Energy Deficiency and Metabolic Perturbation in Male Endurance Athletes
- 2018
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 28:4, s. 419-427
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Tidskriftsartikel (refereegranskat)abstract
- Endurance athletes are at increased risk of relative energy deficiency associated with metabolic perturbation and impaired health. We aimed to estimate and compare within-day energy balance in male athletes with suppressed and normal resting metabolic rate (RMR) and explore whether within-day energy deficiency is associated with endocrine markers of energy deficiency. A total of 31 male cyclists, triathletes, and long-distance runners recruited from regional competitive sports clubs were included. The protocol comprised measurements of RMR by ventilated hood and energy intake and energy expenditure to predict RMR-ratio (measured RMR/predicted RMR), energy availability, 24-hr energy balance and within-day energy balance in 1-hr intervals, assessment of body composition by dual-energy X-ray absorptiometry, and blood plasma analysis. Subjects were categorized as having suppressed (RMRratio < 0.90, n = 20) or normal (RMRratio > 0.90, n = 11) RMR. Despite there being no observed differences in 24-hr energy balance or energy availability between the groups, subjects with suppressed RMR spent more time in an energy deficit exceeding 400 kcal (20.9 [18.8-21.8] hr vs. 10.8 [2.5-16.4], p =.023) and had larger single-hour energy deficits compared with subjects with normal RMR (3,265 +/- 1,963 kcal vs. -1,340 +/- 2,439, p =.023). Larger single-hour energy deficits were associated with higher cortisol levels (r = -.499, p =.004) and a lower testosterone: cortisol ratio (r =.431, p =.015), but no associations with triiodothyronine or fasting blood glucose were observed. In conclusion, within-day energy deficiency was associated with suppressed RMR and catabolic markers in male endurance athletes.
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