Caffeine, Menstrual Cycle, and Performance in Female Volleyball Players

Acute Caffeine Ingestion, Calendar-Based Menstrual-Cycle Window, Time of Day, and Match-Induced Fatigue Independently and Interactively Influence Psychophysiological, Cognitive, and Physical Performance in Elite Female Volleyball Players: A Randomized Double- Blind Placebo-Controlled Crossover Trial

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

PACTR

Registry ID

PACTR202605644954826

Enrollment

Registered

2026-05-20

Start date

2026-05-04

Completion date

Unknown

Last updated

2026-09-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Circulatory System Nutritional, Metabolic, Endocrine

Interventions

acute caffeine ingestion

cellulose placebo group

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: Elite female volleyball players Aged between 18 and 35 years Regular menstrual cycles for the last 6 months (26–32 days) Eumenorrheic status (not using hormonal contraceptives) Active participation in national or international competitions

Exclusion criteria

Exclusion criteria: Use of any hormonal contraceptives or medication affecting the endocrine system History of menstrual cycle irregularities or disorders (e.g., amenorrhea, PCOS) Known sensitivity or allergy to caffeine Musculoskeletal injuries within the last 6 months that limited training Smoking or use of performance-enhancing drugs Pregnancy or breastfeeding

Design outcomes

Primary

Measure	Time frame
Countermovement Jump (CMJ) height and Agility T-test performance	—

Secondary

Measure	Time frame
Cognitive performance (Stroop Test scores) and Psychophysiological measures (Rate of Perceived Exertion - RPE)	—

Countries

Tunisia

Contacts

Public Contactmanel bessifi

High Institute of Sports and Physical Education of Kef University of Jendouba Tunisia

manelbessifii@gmail.com0021697001910

Outcome results

None listed

Source: PACTR (via WHO ICTRP) · Data processed: Sep 19, 2026