Beta-alanine Supplementation and High-intensity Interval Training

Study Overview
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Brief Summary
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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
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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.

Official Title
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Does Beta-alanine Supplementation Augment the Skeletal Muscle Adaptive Response to 8 Weeks of High-intensity Interval Training

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Beta-alanine
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: HIIT + beta-alanine<br>Participants will ingest an active supplement containing beta-alanine for a period of 12 weeks. During the last 8 weeks of that period, participants will take part in a structured program of high-intensity interval training. | Dietary Supplement: Beta-alanine<br>* N/A: see arm description<br>|
| Experimental: HIIT + placebo<br>Participants will ingest a placebo supplement containing no beta-alanine for a period of 12 weeks. During the last 8 weeks of that period, participants will take part in a structured program of high-intensity interval training. | Dietary Supplement: Placebo<br>* N/A: see arm description<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 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. | At weeks 0, 4 and 12 of study. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VO2max | 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. | At weeks 0, 4, 8 and 12 of study. | 
| Substrate utilisation | 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). | At weeks 0, 4 and 12 of study. | 
| Muscle carnosine concentration | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques | At weeks 0, 4 and 12 of study. | 
| Muscle enzyme (citrate synthase, hexokinase, β-HAD, PFK) activity | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques | At weeks 0, 4 and 12 of study. | 
| Muscle buffering capacity | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques | At weeks 0, 4 and 12 of study. | 
| Muscle metabolites (AMP, ADP, ATP, Pi, IMP, PCr, Cr, lactate, pyruvate, NAD+/NADH, glucose, G6P, citrate) | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques | At weeks 0, 4 and 12 of study. | 
| Muscle gene expression | Using the Bergstrom muscle biopsy technique. Samples will be frozen immediately in liquid nitrogen and will be later analysed using validated techniques | At weeks 0, 4 and 12 of study. | 
| Plasma metabolites (NEFA, glucose, glycerol, lactate) | 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. | At weeks 0, 4 and 12 of study. | 
| Heart rate | Heart rate will be measured throughout with the use of a heart rate monitor. | At weeks 0, 4 and 12 of study, and through whole training period (weeks 8-12) |