Tribulus terrestris L. (TT) ingredients have anti-inflammatory and antioxidant activities, but their effects on exercise-induced muscle damage (EIMD) in trained athletes are uncertain. The purpose of this single-blind placebo-controlled trial, in accordance with CONSORT guidelines, was to examine the effect of 6 weeks of TT supplementation on muscle metabolism, inflammation biomarkers, and oxidant status. Thirty trained male CrossFit® athletes were randomly assigned to be supplemented with 770 mg/day of TT (intervention group (IG)) or receive a placebo daily (control group (CG)) for 6 weeks. Muscle damage enzymes, inflammation biomarkers, and Total Antioxidant Status (TAS) were assessed at baseline (T1), 21 days after baseline (T2), and after 42 days (T3). Grace, a Workout of the Day, was measured in T1 and T3. Statistical significance (p < 0.05) was found between IG and CG in Lactate Dehydrogenase (LDH), C-reactive protein (CRP), and TAS levels at the end of the follow-up. Furthermore, TAS levels were significantly (p < 0.05) lower at T2 and T3 relative to baseline in the IG, also LDH and CRP increased significantly (p < 0.05) at T2 and T3 relative to baseline in the CG. No significant (p > 0.05) decreases in muscle damage or inflammation biomarkers were observed, although a slight downward trend was observed after 6 weeks for supplemented athletes. TT supplementation could attenuate the CrossFit® training program-induced oxidative stress, muscle damage, and inflammation which could be due to the natural antioxidant and anti-inflammatory properties of TT.
Keywords: CrossFit®; Tribulus terrestris L.; exercise-induced oxidative stress; herbal supplementation; inflammation response; muscle damage.