Biology of Sport
eISSN: 2083-1862
ISSN: 0860-021X
Biology of Sport
Current Issue Manuscripts accepted About the journal Editorial board Abstracting and indexing Archive Ethical standards and procedures Contact Instructions for authors Journal's Reviewers Special Information
Editorial System
Submit your Manuscript
SCImago Journal & Country Rank
vol. 40
Original paper

Effects of Eurycoma longifolia Jack supplementation on eccentric leg press exercise-induced muscle damage in rugby players

Ahmad Zawawi Zakaria
Jad Adrian Washif
Boon Hooi Lim
Kazunori Nosaka

Sports Performance Division, Institut Sukan Negara Malaysia (National Sports Institute of Malaysia), Malaysia
Sports Centre, University of Malaya, Malaysia
Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Australia
Biol Sport. 2023;40(3):691–697
Online publish date: 2022/09/22
View full text Get citation
PlumX metrics:
Eurycoma longifolia Jack (ELJ) is a herbal plant that has androgenic and antioxidant effects. We investigated the short-term effect of ELJ supplementation on muscle damage induced by eccentric exercise. Eighteen young (19–25 years), well-trained rugby 7s players were assigned to an ELJ or a placebo (PLA) group (n = 9/group). Each participant took four 100-mg capsules a day for seven days prior to performing a leg press eccentric exercise to failure in a double-blind fashion. Peak force, peak power and jump height in countermovement jump (CMJ), drop jump reactive strength index (RSI), muscle soreness assessed by a 100-mm visual analogue scale, plasma creatine kinase (CK) activity, and salivary hormones were measured at 24 h before and 0.5, 24, 48, 72, and 96 h after the exercise. Changes in the variables over time were compared between the groups by two-factor mixed-design ANOVA. The number of eccentric contractions performed was similar (P = 0.984) between the ELJ (21±5) and PLA groups (21±5). Salivary testosterone and cortisol concentrations did not change (P > 0.05) after the supplementation for both groups. CMJ peak power (-9.4 ±5.6%) and height (-10.6±4.9%), and RSI (-15.2±16.2%) decreased at 24 h after exercise (P < 0.05), and muscle soreness (peak: 89 ±10 mm) and plasma CK activity (peak: 739±420 IU/L) increased after exercise (P < 0.05) without significant differences between groups. These results showed that 7-day ELJ supplementation prior to the leg press eccentric exercise had no significant effects on hormones, performance and muscle damage markers for the athletes

herb, salivary testosterone, delayed onset muscle soreness, countermovement jump, drop jump, rugby 7s

Quick links
© 2023 Termedia Sp. z o.o.
Developed by Bentus.