The Cardiovascular Benefits of Resistance Training and Dark Chocolate in Female Adults

The Cardiovascular Benefits of Dark Chocolate Supplementation Before High-intensity Resistance Exercise in the Early Follicular and Mid-luteal Phases of the Menstrual Cycle

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.

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.

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.