Effectiveness of green tea extract (Camellia sinensis) capsule supplementation on post-exercise muscle recovery in healthy adults: a systematic review protocol

OBJECTIVE

The objective of the review is to evaluate the effectiveness of green tea extract (Camellia sinensis) capsule supplementation compared with placebo on post-exercise muscle pain and muscle recovery in healthy adults.

INTRODUCTION

Green tea extract is popularly consumed by athletes and practitioners of physical activity, as it is easily accessible in supermarkets and health food stores. It is a source of catechins, which assist the endogenous antioxidant system in combating free radicals produced during exercise that can lead to oxidative stress and, therefore, muscle damage and delayed-onset muscle pain. However, there is no consensus on the effect of green tea extract and the ideal and safe dosage to promote muscle recovery.

INCLUSION CRITERIA

Studies on the effectiveness of supplementation with green tea extract capsules compared with placebo in post-exercise muscle pain and muscle recovery in healthy adults will be included. Studies that are associated with any other source of polyphenols with green tea extract will be excluded.

METHODS

Studies will be identified using the following databases: Cochrane Library, PubMed, Embase, Web of Science, Virtual Health Library, SPORTDiscus, Science Direct, and Scopus. OpenGrey, DART-Europe, and Google Scholar will be used to identify unpublished studies. Two authors will independently screen titles and abstracts following previously defined eligibility criteria. After excluding irrelevant studies, the authors will read the full texts of any articles potentially eligible for further evaluation. Any disagreements will be resolved by discussion or by consulting a third author. The included studies will be assessed on their methodological quality using the appropriate JBI critical appraisal checklist, and the data will be extracted by the two authors. A meta-analysis will be performed using a random effects or fixed effects model. The heterogeneity of the data will be calculated. This review will follow the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) to classify the certainty of the evidence.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020138772.