Dietary Supplements, Healthy
Conditions
Brief summary
This study aimed to assess if nitrate supplementation influence motor unit (MU) activity following a sustained ischemic contraction and whether this is affected by blood flow restriction (BFR) during the recovery period. Fourteen male participants (mean ± SD, 25 ± 6 years) completed two experimental trials following 5-days of supplementation with either nitrate-rich (NIT) or nitrate-depleted (PLA) beetroot juice in a randomized, double-blinded, cross-over design. Intramuscular electromyography was used to assess MU potential (MUP) size and firing rates (MUFR) during a submaximal (25% MVC) sustained isometric contraction with BFR. These variables were also assessed during a 90 s recovery period with the first half completed with, and the second half completed without, BFR. Nitrate supplementation can expedite the recovery of MUP duration following a sustained ischemic contraction in healthy adults. These novel observations improve understanding of the effects of nitrate on the recovery of neuromuscular function post-exercise and might have implications for recovery of muscle contractile function.
Interventions
DIETARY_SUPPLEMENTNitrate supplementation
Participants ingested 2 × 70 mL/day shots of concentrate nitrate-rich (\ 12.8 mmol/day nitrate) or nitrate-depleted (\ 0.08 mmol/day nitrite) beetroot juice (Beet It, James White Drinks Ltd., Ipswich, UK). Two shots were supplemented for 5 days; one each morning (\ 9 am) and one each evening (\ 9 pm) except for the day of the experimental trial when both shots were taken together 2.5 h before the experimental trial.
DIETARY_SUPPLEMENTPlacebo supplementtaion
2 × 70 mL/day shots of concentrate nitrate-depleted (\ 0.08 mmol/day NO3-) beetroot juice. Two shots were supplemented for 5 days; one each morning (\ 9 am) and one each evening (\ 9 pm) except for the day of the experimental trial when both shots were taken together 2.5 h before the experimental trial.
Sponsors
Manchester Metropolitan University
Northumbria University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)
Masking description
Supplements were allocated in a randomised order and double-blind design by an independent technician who had no further involvement in this study. The randomization and blinding were held until the end of the study.
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Male between 18 - 30 years * free from known respiratory insufficiency, cardiovascular disease and neuro-musculo-skeletal problems at present or in the preceding 6 months. * having at least 5 years competitively (team) sport experience.
Exclusion criteria
* having cardiovascular disease, neuromuscular disease and any lower limb injury and treatment for chronic respiratory complaints.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma Nitrite Level | Pre-exercise | concentration \[nmol\] |
| Motor Unit Activity | Pre-exercise, post-exercise, recovery (45 s) | Duration (ms), area (uV.ms), firing rate (Hz) |
Countries
United Kingdom
Outcome results
None listed