TY - JOUR
T1 - Sex differences and indications of metabolic compensation in within-day energy balance in elite Division 1 swimmers
AU - Lundstrom, Emily A.
AU - Souza, Mary Jane De
AU - Canil, Hannah N.
AU - Williams, Nancy I.
N1 - Funding Information:
The authors thank the members of the Women’s Health and Exercise Laboratory, particularly laboratory technician Ellen Bingham, and statistician consultant Prabhani Kurup-pumullage Don for their important contributions to this research. We also appreciate the extraordinary cooperation of the swimming athletes, coaching staff, and support staff.
Publisher Copyright:
© 2022 The Author(s).
PY - 2023/1
Y1 - 2023/1
N2 - To determine whether mismatched energy intake and expenditure across the day and associated sex differences may be related with metabolic compensation and/or negative health outcomes, we assessed total-day and hourly energy balance (TDEB and EB), total-day and hourly energy intake (TDEI and EI), total-day and hourly energy expenditure (TDEE and EE) and within-day energy balance (WDEB) in elite male and female swimmers (n = 25; 18–22 years). Total triiodothyronine (TT3 ), resting metabolic rate (RMR), and the ratio of actual-to-predicted RMR were determined. Males exhibited higher TDEB (+758 ± 702 kcal vs +52 ± 505 kcal, t-test; p = 0.007) than females. Males exhibited a more positive hourly EB, driven by greater hourly EI at 11:00, 13:00, 16:00, and 19:00 h (ANOVA, p < 0.05), while EE did not differ. TT3 was negatively correlated with consecutive hours of negative EB (R = −0.604, p = 0.049) and positively correlated to hours in EB (R = 0.740, p = 0.009) in those exhibiting metabolic suppression (n = 12). In individuals in TDEB (n = 21), “backloaders” (consumption of ≥50% daily kcals at or after 1700 h) had lower TT3 (79.3 ng/dL vs 92.9 ng/dL, p = 0.009) than “nonbackloaders” (n = 12). WDEB analyses indicate a greater risk of energy deficiency in females and may capture indices of metabolic compensation not evident with EB analyses alone.
AB - To determine whether mismatched energy intake and expenditure across the day and associated sex differences may be related with metabolic compensation and/or negative health outcomes, we assessed total-day and hourly energy balance (TDEB and EB), total-day and hourly energy intake (TDEI and EI), total-day and hourly energy expenditure (TDEE and EE) and within-day energy balance (WDEB) in elite male and female swimmers (n = 25; 18–22 years). Total triiodothyronine (TT3 ), resting metabolic rate (RMR), and the ratio of actual-to-predicted RMR were determined. Males exhibited higher TDEB (+758 ± 702 kcal vs +52 ± 505 kcal, t-test; p = 0.007) than females. Males exhibited a more positive hourly EB, driven by greater hourly EI at 11:00, 13:00, 16:00, and 19:00 h (ANOVA, p < 0.05), while EE did not differ. TT3 was negatively correlated with consecutive hours of negative EB (R = −0.604, p = 0.049) and positively correlated to hours in EB (R = 0.740, p = 0.009) in those exhibiting metabolic suppression (n = 12). In individuals in TDEB (n = 21), “backloaders” (consumption of ≥50% daily kcals at or after 1700 h) had lower TT3 (79.3 ng/dL vs 92.9 ng/dL, p = 0.009) than “nonbackloaders” (n = 12). WDEB analyses indicate a greater risk of energy deficiency in females and may capture indices of metabolic compensation not evident with EB analyses alone.
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U2 - 10.1139/apnm-2022-0161
DO - 10.1139/apnm-2022-0161
M3 - Article
C2 - 36260936
AN - SCOPUS:85146139955
SN - 1715-5312
VL - 48
SP - 74
EP - 87
JO - Applied Physiology, Nutrition and Metabolism
JF - Applied Physiology, Nutrition and Metabolism
IS - 1
ER -