Healthy
Conditions
Brief summary
The present study will seek to quantify whether a period of HIIT alongside β-alanine supplementation will improve the adaptation to training, and therefore performance, more than a period of HIIT alone.
Detailed description
Whilst high-intensity interval training (HIIT) is a powerful stimulus to increase endurance exercise performance, there are potential nutritional interventions that can be put in place to further increase performance gains. Energy for the contraction of muscles is created in the mitochondria. HIIT can improve the function of mitochondria, therefore improving performance. Β-alanine is a commonly used supplement that can improve exercise performance by increasing the amount of carnosine in muscle. Carnosine has many functions that may help improve exercise capacity. The present study will seek to quantify whether a period of HIIT alongside β-alanine supplementation will improve the adaptation to training, and therefore performance, more than a period of HIIT alone.
Interventions
DIETARY_SUPPLEMENTBeta-alanine
N/A: see arm description
DIETARY_SUPPLEMENTPlacebo
N/A: see arm description
Sponsors
University of Exeter
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Masking description
Doubly-blinded & randomised using an online randomisation website.
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Moderately trained (vo2max: 50 - 60 ml/kg/min). * Females must be taking an oral contraceptive, or using a contraceptive implant.
Exclusion criteria
* A recent history of musculoskeletal injury * Diagnosed cardiovascular or metabolic disease * Regular use of beta-alanine supplements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline work done on a cycle ergometer in a cycling capacity test at 110%VO2max following a period of 4 weeks of beta-alanine supplementation and then 8 weeks of beta-alanine supplementation and high intensity interval training | At weeks 0, 4 and 12 of study. | Subjects will have previously performed an incremental test to exhaustion (VO2max test). A work-load that corresponds to 110 % of the peak power output (Wmax) will be calculated, and participants will be asked to cycle at this power output until volitional exhaustion. This test will be preceded but a bout of 90-minute cycling at 65%VO2max. Tests will be performed on a Lode Excalibur Sport, and software linked to the bike will record data. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Substrate utilisation | At weeks 0, 4 and 12 of study. | Substrate utilisation will be calculated from data collected through a metabolic cart and its software. It will be measured during the 90-minute steady-state cycle for 4 periods of 3 minutes. Carbohydrate and lipid oxidation rates will be calculated using equations by Jeukendrup & Wallis (2005). |
| Muscle carnosine concentration | At weeks 0, 4 and 12 of study. | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques |
| Muscle enzyme (citrate synthase, hexokinase, β-HAD, PFK) activity | At weeks 0, 4 and 12 of study. | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques |
| Muscle buffering capacity | At weeks 0, 4 and 12 of study. | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques |
| VO2max | At weeks 0, 4, 8 and 12 of study. | VO2max will be determined from data collected through a metabolic cart. It will be measured during an incremental test to exhaustion performed on a cycle ergometer. |
| Muscle gene expression | At weeks 0, 4 and 12 of study. | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques |
| Plasma metabolites (NEFA, glucose, glycerol, lactate) | At weeks 0, 4 and 12 of study. | A cannula will be used to draw blood from subjects at several time points. Whole blood will be centrifuged immediately and its plasma split into aliquots and stored in a -80°C freezer for later analysis. |
| Heart rate | At weeks 0, 4 and 12 of study, and through whole training period (weeks 8-12) | Heart rate will be measured throughout with the use of a heart rate monitor. |
| Muscle metabolites (AMP, ADP, ATP, Pi, IMP, PCr, Cr, lactate, pyruvate, NAD+/NADH, glucose, G6P, citrate) | At weeks 0, 4 and 12 of study. | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques |
Countries
United Kingdom
Outcome results
None listed