Athletic Performance
Conditions
Keywords
Alpha-GPC, Volleyball, Athletes, Executive functions, Vertical jump, Peak power
Brief summary
In order to attain the elite level on the national scene, volleyball players need several attributes. In addition to mastering technical and tactical skills, great jumping ability is another important asset. Maximal power output needed to achieve height during a jump necessitates coordinated neuromuscular recruitment and muscle mass among others. Interestingly, there are claims that alpha-glycerylphosphorylcholine (A-GPC) increases acetylcholine synthesis and enhances exercise-induced increases in plasma growth hormone concentrations, two factors that could theoretically be associated neuromuscular transmission and muscle mass. However, until now only a few studies have investigated the role of A-GPC in human exercise performance. Published results were mixed. One recent study showed that isometric peak force was slightly but significantly increased when subjects had ingested a daily dose of 600 mg of A-GPC over a period of 6 days (Bellar et al., JISSN, 2015). The objective of our study is to evaluate the longer-term effects (4 weeks) using a higher dose (1000 mg/day) of A-GPC on jumping capabilities in elite male and female volleyball players.
Detailed description
Our study design will be a placebo controlled, randomized, double-blind, crossover study. Varsity male and female volleyball players (n=28) will each be asked to participate in both arms of the study, i.e. placebo and A-GPC (1000 mg/kg/day). The duration of each arm of the study will be 4 weeks separated by a 7-day washout period. The order of treatment (placebo or A-GPC) will be determined randomly. Athletes will be asked to maintain their training load during the duration of the experiment.
Interventions
DIETARY_SUPPLEMENTPlacebo
Monitoring of supplementation (e.g., compliance, subject blindness), diet (to control dietary choline ingestion), training volume and adverse effects will be performed on a weekly basis to ensure maximal control of confounding factors as well as the safety of volunteers during the study.
DIETARY_SUPPLEMENTExperimental
Monitoring of supplementation (e.g., compliance, subject blindness), diet (to control dietary choline ingestion), training volume and adverse effects will be performed on a weekly basis to ensure maximal control of confounding factors as well as the safety of volunteers during the study.
Sponsors
Université de Montréal
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Caregiver)
Eligibility
Sex/Gender
ALL
Age
19 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Be a competitive varsity volleyball player
Exclusion criteria
* Regular consumption of alpha-GPC within the last 4 months * Receiving drug treatment except 1) contraception (pill), and 2) treatment against asthma
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in countermovement jump performance at 4 weeks | Assessments at week 0 and at week 4 of supplementation or placebo | Jump height is calculated using two forces plates which measures the time the feet are off the platform. The athlete stands upright with weight evenly distributed over both feet. Hands are placed on the hips, and stay there throughout the test. When all is ready, the athlete squats down until the knees are bent at 90 degrees, then immediately jumps vertically as high as possible, landing back on the platform on both feet at the same time. Allow a good rest between trials. The take-off must be from both feet, with no initial steps or shuffling. They must also not pause at the base of the squat. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in vertical jump - run up at 4 weeks | Assessments at week 0 and at week 4 of supplementation or placebo | Record the standing height of the subject by getting then to stand directly below the apparatus with both feet on tip-toes, and then stretch up one arm and reach as high as possible. The subject then stands the appropriate distance from the base of the apparatus (about 15 feet), and when ready take 3 or so steps before leaping off up off both legs as high as possible, using the arms to assist in projecting the body upwards. The subject should aim to take off just short of the apparatus, so that at the peak of the jump they are directly under it. |
| Executive function | After 4 weeks of supplementation or placebo | Task switching is a useful tool to investigate executive functions in humans. This task allows investigation of the ability to maintain, select and switch among task sets. |
Countries
Canada
Outcome results
None listed