Cranberry Extract Boosts Endurance Performance

Introduction

This study investigated the effects of a polyphenol-rich cranberry extract (CE) supplement on the performance and physiological markers of trained endurance athletes. The researchers wanted to evaluate whether cranberry supplementation could provide any ergogenic (performance-enhancing) benefits for runners.

Research Purpose and Motivation

The main goal of this study was to explore the potential performance-enhancing effects of cranberry supplementation and understand the underlying physiological mechanisms. The researchers were interested in seeing if cranberry extract could improve running performance and influence key markers like muscle oxygenation and

.

Methodology and Study Design

The study involved 14 trained runners who were tested at three different time points:

1. Baseline
2. 2 hours after an acute dose of cranberry extract (CE)
3. 4 weeks after daily CE consumption (0.3 g/kg body mass per day)

At each time point, the runners performed a 1500-m race and a 400-m race. The researchers used

to measure changes in muscle oxygenation, and they also assessed

blood lactate levels

The concentration of lactic acid in the blood, which can increase during intense physical activity as the body produces more lactate than it can remove. Measuring blood lactate levels can provide information about an athlete's fitness and the intensity of their exercise.

 

at rest and after each race.

Results

The key findings of the study were:

1. Chronic CE supplementation (for 28 days) improved aerobic performance during the 1500-m time trial, with significantly faster

   muscle reoxygenation rates
   Muscle reoxygenation rate is a measure of how quickly the muscles are able to replenish their oxygen supply after it has been depleted during exercise. Faster reoxygenation rates indicate the muscles are better able to recover and continue performing.

    
   and a trend towards slower
   deoxygenation rates
   Deoxygenation rate refers to how quickly the muscles use up their oxygen supply during exercise. Slower deoxygenation rates mean the muscles are able to work for longer periods before becoming fatigued.

    
   compared to baseline.

2. Chronic CE consumption buffered the post-exercise lactate response for the 400-m race, but no effects were observed for the longer 1500-m race.

Conclusions and Implications

The results suggest that cranberry supplementation may have ergogenic effects, improving physiological markers of performance during both short- and long-distance running. The researchers propose that the high

of cranberries may help protect against

exercise-induced free radical production

Free radicals are unstable molecules that can damage cells. Intense exercise can increase the production of free radicals in the body. Antioxidants like those found in cranberries may help neutralize these free radicals and reduce their negative impact on exercise performance.

 

, leading to the observed performance benefits.

Relevance, Potential Impact, and Contributions

This was the first study to evaluate the effect of cranberries on muscle oxygenation using

. The researchers also found moderate correlations between

lactate production

The amount of lactic acid produced by the muscles during exercise, which can be used as a measure of how hard the body is working.

 

, muscle deoxygenation, and running performance, suggesting that the improved

oxygen extraction

The process by which the muscles take in and use the oxygen that is delivered to them during exercise.

 

by the muscle may have contributed to the enhanced running performance with CE supplementation.

Limitations of the study included the lack of a placebo powder and the absence of

measurements, which could have provided insights into the bioavailability of cranberry polyphenols and participant compliance. Future studies should aim to address these limitations and further explore the mechanisms by which cranberry supplementation may improve exercise performance.