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Within‐day energy deficiency and reproductive function in female endurance athletes
Author(s) -
Fahrenholtz I. L.,
Sjödin A.,
Benardot D.,
Tornberg Å. B.,
Skouby S.,
Faber J.,
SundgotBorgen J. K.,
Melin A. K.
Publication year - 2018
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.13030
Subject(s) - basal metabolic rate , medicine , endocrinology , athletes , energy balance , elite athletes , zoology , physical therapy , biology , ecology
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 < 0 kcal: 23.0 hour (20.8‐23.4) vs 21.1 hour (4.7‐22.3), P = .048; WDEB < −300 kcal: 21.8 hour (17.8‐22.4) vs 17.6 hour (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 <0 kcal and <−300 kcal were inversely associated with RMR ratio ( 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.