Cocoa Flavanols Beneficial for Oxygen Uptake

The lack of fitness makes the prospect of starting an exercise routine for sedentary people a daunting task. But supplementing with cocoa powder may ease the couch exit. Researchers in Liverpool, England found sedentary adults had faster oxygen uptake kinetics during exercise after supplementing with cocoa flavanols.

Cocoa flavanols are a nutrient extracted from cocoa beans and are found in abundance in cocoa powder and to a lesser extent in dark chocolate. They can also be found in a supplement form. They have in other studies been shown to have a vasodilatory effect which helps increase blood flow.

Scientists from Liverpool Hope University and Liverpool John Moores University wanted to find out if cocoa flavanols would be beneficial in helping sedentary people ease back into exercise. They worked with a group of people in the 40-60 year-old age range and found some interesting results.

"One barrier to starting an exercise plan is poor fitness in the first place, perhaps because of the discomfort associated with what might otherwise be light exercise,” said Simon Marwood from Liverpool Hope University. "Without frequent exercise, aging results in a slowing in the rate at which our oxygen consumption increases at the onset of exercise. This is due to impairments in the ability to supply blood to the exercising muscles at the onset of exercise.”

Marwood said he found in previous studies a slow rate of oxygen uptake had a direct impact on the ability to tolerate exercise.

"The finding of faster increases in oxygen consumption at the onset of exercise with cocoa flavanols supplementation is therefore really encouraging for this age group since it suggests that a simple nutritional supplement can improve exercise tolerance, and therefore enhance the likelihood of sustaining an exercise program,” Marwood said.

The group of study participants went through some stationary bike exercises to establish a baseline measurement for power output and VO2 max, the maximum amount of oxygen the body can use during exercise. They were then given a 400 mg cocoa flavanol supplement or placebo daily for 7 days.

The participants were then tested on the bicycle for VO2 kinetics, the time it takes for oxygen delivery to respond to the demands of exercise. The study group saw their response time decrease from 40 to 34 seconds, which the researchers considered a significant reduction. Scientists said the reduced response time is consistent with what would be expected in younger, healthier individuals.

"These novel effects of cocoa flavanols in this demographic may contribute to improved tolerance of moderate-activity physical activities, which appear commonly present in daily life,” said researcher Daniel Sadler.

Click here to read more in the European Journal of Applied Physiology.