Sadler 2023 MiP2023

Early life exercise training counters metabolic perturbations imparted by low parental cardiorespiratory fitness.

Link: MiP2023 Obergurgl AT

Sadler Daniel (2023)

Event: MiP2023 Obergurgl AT

Introduction: Low cardiorespiratory fitness (CRF) is associated with a greater risk for metabolic disease. The potential for early life exercise training to overcome metabolic perturbations imparted by low intrinsic CRF remains unknown. We tested the hypothesis that early life exercise training would overcome whole-body and tissue metabolic defects imparted by low CRF.

Methods: At 26 days of age, rat low-capacity runners (LCR, n=20) and high-capacity runners (HCR, n=20) generated by artificial selection were assigned to either sedentary control (CTRL, n=10) or voluntary wheel running (VWR, n=10) for 6 weeks. Post-intervention, whole-body metabolic phenotyping was performed, and the respiratory function of isolated skeletal muscle and liver mitochondria assayed. Quantitative proteomics were performed on tissue samples.

Results and discussion: HCR-VWR performed 1.8-fold greater volume of wheel running than LCR-VWR (P<0.001). In LCR, VWR reduced body fat (P<0.001), increased total daily energy expenditure (+16 %, P=0.030), and enhanced glucose tolerance (P=0.040). Muscle mitochondrial respiratory function was unaffected by VWR in both strains, although VWR increased muscle mitochondrial protein content (both P<0.05). VWR enhanced the respiratory capacity of HCR hepatic mitochondria (+23%, P=0.040). Proteomic analyses revealed lower capacity for fatty acid oxidation in muscle and liver of LCR-CTRL versus HCR-CTRL, which was not rescued by VWR. VWR reduced hepatic pyruvate kinase abundance in both strains (both P<0.013), indicating VWR may shift fuel preferences of hepatic mitochondria. These results reveal early life exercise training partially overcomes the metabolic phenotype imparted by low intrinsic CRF, although proteomic adaptations to early exercise training remain influenced by intrinsic CRF.

• Keywords: exercise, aerobic capacity, mitochondria, metabolism

• O2k-Network Lab: US AR Little Rock Borsheim E

Labels: MiParea: Exercise physiology;nutrition;life style 

Organism: Rat  Tissue;cell: Skeletal muscle, Liver 

Event: E2 

Funding: This study was supported by the USDA-ARS (USDA ARS 6026-51000-012-06S) and in part, by Arkansas Children’s Research Institute and the Arkansas Biosciences Institute; ABIPG4622.