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- Ekman, Carl, et al.
(author)
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Less pronounced response to exercise in healthy relatives to type 2 diabetic subjects compared with controls
- 2015
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In: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 119:9, s. 953-960
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Journal article (peer-reviewed)abstract
- Healthy first-degree relatives with heredity of type 2 diabetes (FH+) are known to have metabolic inflexibility compared with subjects without heredity for diabetes (FH-). In this study, we aimed to test the hypothesis that FH+ individuals have an impaired response to exercise compared with FH-. Sixteen FH+ and 19 FH- insulin-sensitive men similar in age, peak oxygen consumption ((V) over dot(O2 peak)), and body mass index completed an exercise intervention with heart rate monitored during exercise for 7 mo. Before and after the exercise intervention, the participants underwent a physical examination and tests for glucose tolerance and exercise capacity, and muscle biopsies were taken for expression analysis. The participants attended, on average, 39 training sessions during the intervention and spent 18.8 MJ on exercise. (V) over dot(O2 peak)/kg increased by 14%, and the participants lost 1.2 kg of weight and 3 cm waist circumference. Given that the FH- group expended 61% more energy during the intervention, we used regression analysis to analyze the response in the FH+ and FH- groups separately. Exercise volume had a significant effect on (V) over dot(O2 peak), weight, and waist circumference in the FH- group, but not in the FH+ group. After exercise, expression of genes involved in metabolism, oxidative phosphorylation, and cellular respiration increased more in the FH- compared with the FH+ group. This suggests that healthy, insulin-sensitive FH+ and FH- participants with similar age, (V) over dot(O2 peak), and body mass index may respond differently to an exercise intervention. The FH+ background might limit muscle adaptation to exercise, which may contribute to the increased susceptibility to type 2 diabetes in FH+ individuals.
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| 2. |
- Tornberg, Åsa B.B., et al.
(author)
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Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes
- 2017
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In: Medicine & Science in Sports & Exercise. - : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 49:12, s. 2478-2485
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Journal article (peer-reviewed)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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