Increased Brain Glucose Uptake After 12 Weeks of Aerobic High-Intensity Interval Training in Young and Older Adults

Abstract

Context: Aerobic exercise training can increase brain volume and blood flow, but the impact on brain metabolism is less known.

Objective: We determined whether high-intensity interval training (HIIT) increases brain metabolism by measuring brain glucose uptake in younger and older adults.

Design: Brain glucose uptake was measured before and after HIIT or a sedentary (SED) control period within a larger exercise study.

Setting: Study procedures were performed at the Mayo Clinic in Rochester, MN.

Participants: Participants were younger (18 to 30 years) or older (65 to 80 years) SED adults who were free of major medical conditions. Group sizes were 15 for HIIT (nine younger and six older) and 12 for SED (six younger and six older).

Intervention: Participants completed 12 weeks of HIIT or SED. HIIT was 3 days per week of 4 × 4 minute intervals at over 90% of peak aerobic capacity (VO2peak) with 2 days per week of treadmill walking at 70% VO2peak.

Main outcome measures: Resting brain glucose uptake was measured using 18F-fluorodeoxyglucose positron emission tomography scans at baseline and at week 12. Scans were performed at 96 hours after exercise. VO2peak was measured by indirect calorimetry.

Results: Glucose uptake increased significantly in the parietal-temporal and caudate regions after HIIT compared with SED. The gains with HIIT were not observed in all brain regions. VO2peak was increased for all participants after HIIT and did not change with SED.

Conclusion: We demonstrate that brain glucose metabolism increased after 12 weeks of HIIT in adults in regions where it is reduced in Alzheimer's disease.

Trial registration: ClinicalTrials.gov NCT01738568.

Copyright © 2017 Endocrine Society

Figures

Figure 1.

(A) Individual data points for change from premeasurement to postmeasurements of brain glucose uptake by 18FDG-PET in left parietal and temporal lobes and the right caudate nucleus after 12 weeks of SED or HIIT in young and older adults. (B) The change in ΔVO2peak from baseline was greater after HIIT than after SED. (C) There was no correlation between ΔVO2peak after HIIT and change in regional brain glucose uptake (left parietal region displayed). For panels (A) and (B), the horizontal bars indicate mean for SED or HIIT, and the dotted line at zero indicates no change from baseline. *P < 0.05; ***P < 0.001 for the main effect of training from two-way ANOVA (age × training).