| 1. |
- 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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| 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. |
- 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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| 4. |
- Lundy, Bronwen, et al.
(författare)
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Screening for Low Energy Availability in Male Athletes : Attempted Validation of LEAM-Q
- 2022
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- A questionnaire-based screening tool for male athletes at risk of low energy availability (LEA) could facilitate both research and clinical practice. The present options rely on proxies for LEA such screening tools for disordered eating, exercise dependence, or those validated in female athlete populations. in which the female-specific sections are excluded. To overcome these limitations and support progress in understanding LEA in males, centres in Australia, Norway, Denmark, and Sweden collaborated to develop a screening tool (LEAM-Q) based on clinical investigations of elite and sub-elite male athletes from multiple countries and ethnicities, and a variety of endurance and weight-sensitive sports. A bank of questions was developed from previously validated questionnaires and expert opinion on various clinical markers of LEA in athletic or eating disorder populations, dizziness, thermoregulation, gastrointestinal symptoms, injury, illness, wellbeing, recovery, sleep and sex drive. The validation process covered reliability, content validity, a multivariate analysis of associations between variable responses and clinical markers, and Receiver Operating Characteristics (ROC) curve analysis of variables, with the inclusion threshold being set at 60% sensitivity. Comparison of the scores of the retained questionnaire variables between subjects classified as cases or controls based on clinical markers of LEA revealed an internal consistency and reliability of 0.71. Scores for sleep and thermoregulation were not associated with any clinical marker and were excluded from any further analysis. Of the remaining variables, dizziness, illness, fatigue, and sex drive had sufficient sensitivity to be retained in the questionnaire, but only low sex drive was able to distinguish between LEA cases and controls and was associated with perturbations in key clinical markers and questionnaire responses. In summary, in this large and international cohort, low sex drive was the most effective self-reported symptom in identifying male athletes requiring further clinical assessment for LEA.
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| 5. |
- 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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| 6. |
- 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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