Related Experiment Video
Updated: Feb 1, 2026

Author Spotlight: Exploring the Impact of Reduced Resistance Exercise Volume on Metabolic Health
Published on: December 1, 2023
Effects of regular high-cocoa chocolate intake on arterial stiffness and metabolic characteristics during exercise
Masato Nishiwaki1, Yuri Nakano1, Naoyuki Matsumoto2
1Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan.
Objective:
The aim of this study was to examine the effects of regular high-cocoa chocolate consumption on arterial stiffness and fat oxidation during light- to moderate-intensity exercise.
Methods:
This randomized, controlled, parallel-group intervention study included 32 Japanese college students (mean age, 20.7 ± 0.3 y; men, n = 24; women, n = 8) who were assigned to either control or intervention groups (n = 16 each). The control group did not alter their habitual diet or physical activity throughout the study period. The intervention group consumed 20 g/d (508 mg of cacao polyphenol) of high-cocoa chocolate for 4 wk. Blood pressure, heart-ankle pulse wave velocity, cardio-ankle vascular index, body composition, and metabolic characteristics during exercise at 50% maximal oxygen uptake level were assessed before and after the intervention.
Results:
Four weeks of high-cocoa chocolate ingestion significantly reduced heart-ankle pulse wave velocity and cardio-ankle vascular index (%change, intervention versus control: -2.3 ± 0.9% versus 0.9 ± 0.9%, and -4.8 ± 1.8% versus 0.7 ± 1.3%, respectively; both P < 0.05). However, blood pressure, weight, body mass index, body fat, waist circumference, and metabolic characteristics during exercise such as respiratory exchange ratio did not significantly change in either group.
Conclusions:
Four weeks of regular high-cocoa chocolate consumption reduced arterial stiffness after considering blood pressure in healthy young men and women. However, the habitual consumption of high-cocoa chocolate for 4 wk did not affect metabolic characteristics during light- to moderate-intensity exercise and body composition.
Related Concept Videos
What is Metabolism?
Regulation of Water Intake
Regulation of Food Intake
Characteristics of Life
Exercise Stress Test
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes
Characteristics of Fluids

