The aim of this study is to determine the contribution of intramuscular vs circulating sources of lipid and carbohydrate to exercise fuel utilization in males and females and to determine the post-exercise changes in hormone and fuel metabolism. It has previously been shown that females utilize proportionally more fat, whereas males utilize proportionally more carbohydrate, during moderate exercise. The combination of indirect calorimetry and stable isotope techniques will be used to determine potential gender differences in the contribution of intramuscular vs circulating fuels to whole body lipid and carbohydrate oxidation. Simultaneously, the circulating hormone environment will be determined to ascertain any relationship with patterns of nutrient utilization. Subjects follow 3 days of controlled diet and are studied in the morning after an overnight fast. Following resting measurements, cycle exercise is performed for 90 minutes, at a steady state intensity of 90% lactate threshold. Subjects then rest for 3 hours with measurements continuing throughout the post-exercise period. It is hypothesized that a) the greater proportional fat oxidation in females will be due to a greater utilization of intramuscular triglyceride (and possibly very-low density lipoprotein triglyceride) b) the greater proportional carbohydrate oxidation in males will be due to a greater utilization of both muscle glycogen and blood glucose c) post-exercise circulating FFA oxidation will be greater in males whereas FFA re-esterification will be greater in females. In this way, females may minimize both utilization of peripheral lipid stores and endogenous glucose. This has implications for gender differences in the mechanisms controlling body fat stores and lipid/carbohydrate interactions.

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University of Colorado Denver
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Millstein, Richard J; Pyle, Laura L; Bergman, Bryan C et al. (2018) Sex-specific differences in insulin resistance in type 1 diabetes: The CACTI cohort. J Diabetes Complications 32:418-423
Martin, Maureen P; Naranbhai, Vivek; Shea, Patrick R et al. (2018) Killer cell immunoglobulin-like receptor 3DL1 variation modifies HLA-B*57 protection against HIV-1. J Clin Invest 128:1903-1912
Nowak, Kristen L; You, Zhiying; Gitomer, Berenice et al. (2018) Overweight and Obesity Are Predictors of Progression in Early Autosomal Dominant Polycystic Kidney Disease. J Am Soc Nephrol 29:571-578
Haas, David W; Bradford, Yuki; Verma, Anurag et al. (2018) Brain neurotransmitter transporter/receptor genomics and efavirenz central nervous system adverse events. Pharmacogenet Genomics 28:179-187
Venuto, Charles S; Lim, Jihoon; Messing, Susan et al. (2018) Inflammation investigated as a source of pharmacokinetic variability of atazanavir in AIDS Clinical Trials Group protocol A5224s. Antivir Ther 23:345-351
Li, Binglan; Verma, Shefali S; Veturi, Yogasudha C et al. (2018) Evaluation of PrediXcan for prioritizing GWAS associations and predicting gene expression. Pac Symp Biocomput 23:448-459
Hayden, Kathleen M; Baker, Laura D; Bray, George et al. (2018) Long-term impact of intensive lifestyle intervention on cognitive function assessed with the National Institutes of Health Toolbox: The Look AHEAD study. Alzheimers Dement (Amst) 10:41-48
Shah, V N; Sippl, R; Joshee, P et al. (2018) Trabecular bone quality is lower in adults with type 1 diabetes and is negatively associated with insulin resistance. Osteoporos Int 29:733-739
Jensen, Thomas; Bjornstad, Petter; Johnson, Richard J et al. (2018) Copeptin and Estimated Insulin Sensitivity in Adults With and Without Type 1 Diabetes: The CACTI Study. Can J Diabetes :
Dad, Taimur; Abebe, Kaleab Z; Bae, K Ty et al. (2018) Longitudinal Assessment of Left Ventricular Mass in Autosomal Dominant Polycystic Kidney Disease. Kidney Int Rep 3:619-624

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