Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
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.
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Beetroot Juice | Active Comparator | The subject will ingest 140mL of a nitrate-rich beetroot juice each day for 7 consecutive days. |
|
| Placebo Beetroot Juice | Placebo Comparator | The subject will ingest 140mL of a placebo (nitrate-depleted) beetroot juice each day for 7 consecutive days. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Beetroot Juice | Dietary Supplement | 7 days of 140 mL per day of beetroot juice |
|
| Measure | Description | Time Frame |
|---|---|---|
| Change 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. | 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) |
| Measure | Description | Time Frame |
|---|---|---|
| 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. |
| Measure | Description | Time Frame |
|---|---|---|
| Change in plasma nitrate concentration with beetroot juice supplementation | Plasma nitrate concentration will be quantified using a nitrate colorimetric assay. Plasma nitrate concentration after 7 days of beetroot juice supplementation will be compared with plasma nitrate concentration after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
| Name | Role | Phone | Extension | |
|---|---|---|---|---|
| Timothy Fulton, PhD | Contact | 319-290-5529 | timothy.fulton@marquette.edu |
Not provided
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Marquette University | Recruiting | Milwaukee | Wisconsin | 53233 | United States |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Placebo Beetroot Juice | Other | 7 days of 140 mL per day of placebo beetroot juice |
|
| 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. | 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) |
| 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 plasma nitrite concentration with beetroot juice supplementation | Plasma nitrite concentration will be quantified using a nitrite colorimetric assay. Plasma nitrite concentration after 7 days of beetroot juice supplementation will be compared with plasma nitrite concentration after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. | 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) |