Clinical trial NCT06908941: The Cardiovascular Benefits of Resistance Training and Dark Chocolate in Female Adults
Official title: The Cardiovascular Benefits of Dark Chocolate Supplementation Before High-intensity Resistance Exercise in the Early Follicular and Mid-luteal Phases of the Menstrual Cycle
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vascular Function in Healthy Volunteers
Keywords: dark chocolate
estrogen
cardiovascular function
Lead sponsor: National Cheng Kung University
Sponsor class: OTHER
First posted: 2025-04-03
Enrollment: 31
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: EF-MC: early follicular-milk chocolate EF-DC: early follicular-dark chocolate ML-MC: Mid Luteal-milk chocolate ML-DC: Mid Luteal-dark chocolate
Primary purpose: PREVENTION

Brief summary: This study investigates the effects of 85% dark chocolate supplementation on vascular function and nitric oxide (NO) levels during high-intensity resistance exercise in healthy women across menstrual phases. Using a randomized crossover design, 31 women consumed either dark chocolate or milk chocolate before exercising during the early follicular and mid-luteal phases. Vascular markers, including pulse wave velocity (ftPWV), arterial stiffness, blood pressure, and plasma NO levels, were measured at multiple time points.

Detailed description: Background:

Dark chocolate, rich in flavanols, may support vascular health by reducing arterial stiffness and blood pressure across menstrual phases. This study examined the effects of 85% dark chocolate on nitric oxide (NO) levels and vascular function during high-intensity resistance exercise in healthy women across the early follicular and mid-luteal phases.

Methods:

Thirty-one healthy women (aged 20-30 years) with regular menstrual cycles completed a randomized, crossover study (conducted at National Chung Cheng University, Sep-Dec 2023). Participants consumed either 85% dark chocolate or milk chocolate (1g/kg body weight) before high-intensity resistance exercise during the early follicular (days 2-5) and mid-luteal (days 18-24) phases of two menstrual cycles. Finger-toe pulse wave velocity (ftPWV), arterial stiffness, blood pressure, and plasma NO levels were measured at rest, 2 hours after chocolate consumption (baseline), immediately post-exercise (T0), and at 60 (T60) and 120 (T120) minutes post-exercise.

Eligibility criteria: Inclusion Criteria:

* the healthy adult women,
* aged 20-30 years, from a local university campus,
* had a regular menstrual cycles in the past three months.

Exclusion Criteria:

* (1) irregular menstrual cycles (menstrual cycle length \< 21 or \> 35 days in the past three months),
* (2) pregnancy or lactation in the past year,
* (3) history of cardiovascular or uterine surgery in the past six months,
* (4) use of contraceptives or other female hormone medications,
* (5) smoking or alcohol consumption habits,
* (6) hypertension (blood pressure \> 140/90 mmHg), chronic diseases, heart disease, or other cardiovascular conditions, (7) allergy to cocoa products, nuts, or fruits.

Primary outcomes:
measure: Finger-Toe Pulse Wave Velocity (ftPWV)
timeFrame: Finger-toe pulse wave velocity (ftPWV) were measured at rest, 2 hours after chocolate consumption (baseline), immediately post-exercise (T0), and at 60 (T60) and 120 (T120) minutes post-exercise.
Secondary outcomes:
measure: Arterial Index
timeFrame: Arterial index (API and AVI) were measured at rest, 2 hours after chocolate consumption (baseline), immediately post-exercise (T0), and at 60 (T60) and 120 (T120) minutes post-exercise.
Other outcomes:
Locations:
city: Chiayi County, Taiwan
country: Taiwan
facility: National Chung Cheng University
Study officials:
affiliation: National Chung Cheng University
name: Cheng-Shiun He Professor
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gaynor-Metzinger SHA, Triplett NT, Meucci M, Fasczewski KS, Flinchum DH, Collier SR. Central arterial stiffness, wave reflection, and heart rate variability following 4-week high-intensity resistance training intervention in young active women. Eur J Appl Physiol. 2022 Oct;122(10):2283-2293. doi: 10.1007/s00421-022-05003-4. Epub 2022 Jul 19.