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Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes

Tornberg, Åsa B.B. LU ; Melin, Anna LU ; Manderson Koivula, Fiona; Johansson, Anders LU ; Skouby, Sven; Faber, Jens and Sjödin, Anders (2017) In Medicine and Science in Sports and Exercise
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 (DXA);; 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 3rd-5th day of the menstrual cycle, and 7-day assessment of energy availability. RESULTS: SFHA athletes had lower estrogen... (More)

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 (DXA);; 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 3rd-5th day of the menstrual cycle, and 7-day assessment of energy availability. RESULTS: SFHA athletes had lower estrogen (0.12 ±0.03 vs. 0.17 ±0.09 nmol/L, p<0.05), triiodothyronine (T3) (1.4 ±0.2 vs. 1.7 ±0.3 nmol/L, p<0.01), and blood glucose (3.8 ±0.3 vs 4.4 ±0.3 mmol/L, p<0.001) but higher cortisol levels (564 ±111 vs. 400 ±140 nmol/L, p<0.05) compared to 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 O2/min/kg). RT was 7% longer, and KMS and KME were 11% and 20% lower compared to EUM athletes. RT was negatively associated with glucose (r=-0.40, p<0.05), T3 (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 differences in KMS, while reproductive function and FFMleg independently explained the variability in KME. CONCLUSION: We found lower neuromuscular performance among SFHA compared to EUM athletes linked to a lower FFMleg, glucose, estrogen, T3 and elevated cortisol levels.

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publication status
epub
subject
in
Medicine and Science in Sports and Exercise
publisher
Lippincott Williams & Wilkins
external identifiers
  • scopus:85025160119
ISSN
0195-9131
DOI
10.1249/MSS.0000000000001383
language
English
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yes
id
db0c2670-2403-4550-9801-c4e25c6b26a2
date added to LUP
2017-08-28 16:33:45
date last changed
2017-08-29 03:00:02
@article{db0c2670-2403-4550-9801-c4e25c6b26a2,
  abstract     = {<p>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 (DXA);; 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 3rd-5th day of the menstrual cycle, and 7-day assessment of energy availability. RESULTS: SFHA athletes had lower estrogen (0.12 ±0.03 vs. 0.17 ±0.09 nmol/L, p&lt;0.05), triiodothyronine (T3) (1.4 ±0.2 vs. 1.7 ±0.3 nmol/L, p&lt;0.01), and blood glucose (3.8 ±0.3 vs 4.4 ±0.3 mmol/L, p&lt;0.001) but higher cortisol levels (564 ±111 vs. 400 ±140 nmol/L, p&lt;0.05) compared to EUM athletes. SFHA had a lower body weight (55.0 ±5.8 vs. 60.6 ±7.1 kg, p&lt;0.05), but no difference in exercise capacity between groups was found (56.4 ±5.8 vs. 54.0 ±6.3 ml O2/min/kg). RT was 7% longer, and KMS and KME were 11% and 20% lower compared to EUM athletes. RT was negatively associated with glucose (r=-0.40, p&lt;0.05), T3 (r=-0.37, p&lt;0.05) and estrogen (r=-0.43, p&lt;0.05), but positively associated with cortisol (r=0.38, p&lt;0.05). KMS and KME correlated with fat free mass in the tested leg (FFMleg)(r=0.52, p&lt;0.001; r=0.58, p&lt;0.001) but were negatively associated with cortisol (r=-0.42, p&lt;0.05; r=-0.59, p&lt;0.001). FFMleg explained differences in KMS, while reproductive function and FFMleg independently explained the variability in KME. CONCLUSION: We found lower neuromuscular performance among SFHA compared to EUM athletes linked to a lower FFMleg, glucose, estrogen, T3 and elevated cortisol levels.</p>},
  author       = {Tornberg, Åsa B.B. and Melin, Anna and Manderson Koivula, Fiona and Johansson, Anders and Skouby, Sven and Faber, Jens and Sjödin, Anders},
  issn         = {0195-9131},
  language     = {eng},
  month        = {07},
  publisher    = {Lippincott Williams & Wilkins},
  series       = {Medicine and Science in Sports and Exercise},
  title        = {Reduced Neuromuscular Performance in Amenorrheic Elite Endurance Athletes},
  url          = {http://dx.doi.org/10.1249/MSS.0000000000001383},
  year         = {2017},
}