Caffeine, Muscle Strength, Paralympic Athletes, Physical Endurance
Conditions
Brief summary
Background: Sitting volleyball is a sport that relies primarily on upper body strength and anaerobic capacity. In critical in-game skills such as serve and spike, factors such as speed-endurance time and impact power play a decisive role in performance. There are limited studies in the literature examining the effects of low-dose caffeine consumption on these skills. The effects of ergogenic supplements in Paralympic sports have not been sufficiently investigated, and the potential benefits of caffeine on serve and spike performance in sitting volleyball players remain unclear. Purpose: The main purpose of this research was to determine the effects of low-dose caffeine (3 mg/kg) consumption on the serve speed, spike speed and Speed-Endurance performances of elite-level sitting volleyball players. Method: The study was designed using a randomized, double-blind, balanced, and crossover experimental design. 13 elite male athletes from the 2024 Paravolley European Champion Sitting Volleyball Men's National Team participated in the study. Participants were evaluated for serve speed, spike speed, and speed-endurance performances in both 3 mg/kg caffeine (CAF) and placebo (PLA) conditions.
Detailed description
This study aimed to investigate the effects of low-dose caffeine ingestion on key performance parameters in elite-level sitting volleyball athletes. Sitting volleyball is a Paralympic sport that relies heavily on upper body explosive strength and short-term anaerobic power. While caffeine is a well-known ergogenic aid in able-bodied sports, its role in Paralympic contexts remains underexplored. Using a randomized, double-blind, placebo-controlled crossover design, the effects of 3 mg/kg caffeine consumption were assessed in 13 elite male sitting volleyball players. Each participant completed performance assessments under both caffeine and placebo conditions. The primary goal was to examine whether caffeine intake would enhance serve speed, spike speed, and repeated sprint ability. The study provides new insights into the acute ergogenic effects of caffeine in Paralympic team sport athletes, highlighting its selective benefit on explosive upper-body tasks such as serving.
Interventions
DIETARY_SUPPLEMENTCaffeine
A single oral dose of 3 mg of caffeine per kilogram of body weight form approximately 60 minutes before performance testing. Supplied by Oxford Vitality, ISO-certified.
DIETARY_SUPPLEMENTPlacebo
polydextrose used as Placebo
Sponsors
Ulaç Can YILDIRIM
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
No
Inclusion criteria
* Male sitting volleyball players aged between 18 and 40 * Member of the 2024 National Sitting Volleyball Team * At least 3 years of competitive playing experience * No caffeine consumption 48 hours prior to testing * Provided informed consent to participate
Exclusion criteria
* Known cardiovascular, neurological, or metabolic disorders * Current use of medications that may affect caffeine metabolism * Allergy or sensitivity to caffeine * Use of performance-enhancing substances within the last month
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Serve Speed | After 60 minutes ingestion of the supplement on test day (CAF and PLA) | Serve speed will be assessed using a calibrated radar device to record peak velocity of each participant's volleyball serve. |
| Spike Speed | After 60 minutes ingestion of the supplement on test day (CAF and PLA) | Maximum spike speed will be measured in kilometers per hour (km/h) using a radar gun during a standardized spike task conducted after supplementation in each condition. |
| Speed-Endurance | After 60 minutes ingestion of the supplement on test day (CAF and PLA) | The number of maximal shuttle runs completed in a repeated sprint ability (RSA) test protocol will be recorded to assess speed-endurance capacity. |
Countries
Turkey (Türkiye)
Outcome results
None listed