Volleyball Players, Performance
Conditions
Keywords
Caffeine, Caffeinated gum, Volleyball, Athletic performance, Vertical jump
Brief summary
This study examined the acute effects of caffeinated chewing gum on volleyball performance in trained female volleyball players. Caffeine is commonly used by athletes to improve performance, but less is known about whether caffeinated gum is useful during volleyball-specific activity. Participants completed three testing sessions in a randomized crossover design. In one session, they chewed placebo gum. In another session, they chewed caffeinated gum containing a single 300 mg dose of caffeine. In the third session, they received the same total amount of caffeine as three separate 100 mg doses given at 30-minute intervals. The study assessed volleyball-specific skill performance, including attack, block, and defense efficiency, during a volleyball-specific skill game. Vertical jump height, heart rate, perceived exertion, side effects, and condition guessing were also recorded.
Detailed description
This randomized, placebo-controlled, crossover study investigated whether the pattern of caffeinated gum administration affects volleyball-specific performance in trained female volleyball players. Participants completed one familiarization session and three experimental sessions separated by one week. The experimental conditions were placebo gum, single-dose caffeinated gum, and partial-dose caffeinated gum. In the single-dose condition, participants chewed three pieces of caffeinated gum containing a total of 300 mg caffeine for 5 minutes. In the partial-dose condition, participants chewed one piece of caffeinated gum containing 100 mg caffeine at three different time points, with 30-minute intervals between doses. In the placebo condition, participants chewed caffeine-free gum for 5 minutes. Each testing session included volleyball-specific activities and a 30-minute volleyball-specific skill game. Attack, block, and defense efficiency were assessed using video recordings and Data Volley software. Vertical jump height was measured before and after the volleyball-specific activity. Heart rate was recorded during the session, and rating of perceived exertion was assessed before and after the session. Participants were also asked to report side effects and to guess which condition they had received after each session.
Interventions
DIETARY_SUPPLEMENTSingle-dose caffeinated gum
Participants chewed three pieces of caffeinated gum containing 100 mg caffeine per piece, providing a total dose of 300 mg caffeine. The gum was chewed for 5 minutes and then discarded.
DIETARY_SUPPLEMENTPartial-dose caffeinated gum
Participants received three separate pieces of caffeinated gum containing 100 mg caffeine per piece. One piece was chewed for 5 minutes at each administration time point, with doses given at 30-minute intervals, providing a total dose of 300 mg caffeine.
DIETARY_SUPPLEMENTPlacebo gum
Participants chewed caffeine-free placebo gum for 5 minutes. The placebo gum was selected to be similar in shape and color to the caffeinated gum.
Sponsors
Ege University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Female volleyball players aged 18 to 35 years. * Apparently healthy. * Daily caffeine intake ≤300 mg. * Minimum of 5 years of regular volleyball training experience. * Training for at least 120 minutes at least 3 days per week. * Competing in national or international volleyball matches. * Provided written informed consent before participation.
Exclusion criteria
* Serious injury or trauma within the past 6 months that could affect volleyball performance. * Illness or inability to continue the study protocol during the research period. * Development of side effects during caffeinated gum administration that prevented continuation. * Regular alcohol or drug use that could affect the study outcomes.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Attack efficiency | During the 30-minute volleyball-specific skill game in each experimental trial | Attack efficiency was assessed during a 30-minute volleyball-specific skill game using video recordings and Data Volley software. Values were expressed as percentages. |
| Block efficiency | During the 30-minute volleyball-specific skill game in each experimental trial | Block efficiency was assessed during a 30-minute volleyball-specific skill game using video recordings and Data Volley software. Values were expressed as percentages. |
| Defense efficiency | During the 30-minute volleyball-specific skill game in each experimental trial | Defense efficiency was assessed during a 30-minute volleyball-specific skill game using video recordings and Data Volley software. Values were expressed as percentages. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in vertical jump height | From immediately before to immediately after each experimental trial | Vertical jump height was measured before and after each experimental testing session using a photoelectric cell system. Values were expressed in centimeters. |
| Heart rate | Continuously during each experimental trial | Heart rate was recorded during each experimental testing session using a telemetric heart rate monitoring system. Values were expressed as beats per minute. |
| Change in rating of perceived exertion | From immediately before to immediately after each experimental trial | Rating of perceived exertion was assessed before and after each experimental testing session using a 0-10 Borg scale. |
Countries
Turkey (Türkiye)
Outcome results
None listed