Healthy Adults
Conditions
Keywords
isometric strength, beetroot, nitrates, local muscle endurance, supplementation
Brief summary
This is a double-blind placebo-controlled cross-over trial that aims to determine the acute effect of beetroot juice ingestion on isometric knee extension strength, explosive strength and local muscular endurance.
Detailed description
The study aims to determine whether concentrated beetroot juice has an acute effect on isometric strength of the knee muscles and the rate of force development in knee extension, as well as endurance of the same muscle. This will be a cross-over study. 20 subjects will be randomly selected to the experimental group or control group; after 1 week, participants will repeat the measurements in the other condition. Subjects will consume 140 ml of beetroot juice extract 2.5 hours before the measurement or placebo (140 ml of blackcurrant juice with added appropriate amount of sugar to equalize the carbohydrate value and lemon juice fort the taste). An isometric dynamometer will be used to measure the isometric strength of the knee extensors. Investigators will quantify peak force, rate of force development, endurance of knee extensors at 50 % of the maximal force, and the force recovery after a fatiguing protocol.
Interventions
DIETARY_SUPPLEMENTBeetroot juice concentrate (140 ml)
A beetroot juice concentrate (140 ml) will be administered to participants in experimental conditions.
DIETARY_SUPPLEMENTBlackcurrant juice (placebo)
140 ml of blackcurrant juice with added appropriate amount of sugar to equalize the carbohydrate value and lemon juice fort the taste.
Sponsors
University of Primorska
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Age between 18 and 30 years * Physically active and healthy athletes (recreational or professional)
Exclusion criteria
* Cardiovascular, pulmonary, metabolic, neurological diseases and musculoskeletal injuries * Smokers * Consumption of drugs such as antacids and proton pump inhibitors in the previous 3 months * Pregnant or breastfeeding women * Beetroot allergic participants
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Knee extension strength | 2 hours after the ingestion of beetroot juice or placebo | The peak force during maximal voluntary contraction of knee extensors |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Knee extension explosive strength | 2 hours after the ingestion of beetroot juice or placebo | The rate of force development during maximal voluntary contraction of knee extensors |
| Knee extension local muscle endurance | 2 hours after the ingestion of beetroot juice or placebo | Time to failure of knee muscles at 50 % of maximal force |
Countries
Slovenia
Outcome results
None listed