Vascular and skeletal muscle function decline with age and are associated with decreased nitric oxide (NO) bioavailability. Dietary nitrate supplementation in the form of beet root juice increases NO bioavailability and improves exercise tolerance in younger adults, yet its effects on fatigability in older adults are largely unknown. The proposed research will investigate the impact of increased NO bioavailability on vascular function, skeletal muscle bioenergetics, and fatigability in older (≥65 yrs) men and women.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Enrollment
40
7 days of 140 mL per day of beetroot juice
7 days of 140 mL per day of placebo beetroot juice
Marquette University
Milwaukee, Wisconsin, United States
RECRUITINGChange in fatigability of the knee extensor muscles with beetroot juice supplementation
Fatigability will be quantified as the reduction in limb muscle power output during a 4-minute dynamic fatiguing exercise task using a dynamometer. Fatigability after 7 days of beetroot juice supplementation will be compared with fatigability after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions.
Time frame: Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation)
Change in femoral artery blood flow with beetroot juice supplementation
Femoral artery blood flow will be quantified as the change in femoral artery blood flow during a 4-minute dynamic fatiguing exercise task using a ultrasonography. Femoral artery blood flow after 7 days of beetroot juice supplementation will be compared with Femoral artery blood flow after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions.
Time frame: Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation)
Change in muscle efficiency with beetroot juice supplementation
Muscle efficiency will be quantified as the ATP cost of contraction using phosphorus magnetic resonance spectroscopy (P-MRS). Muscle efficiency after 7 days of beetroot juice supplementation will be compared with muscle efficiency after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions.
Time frame: Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.