The World Health Organization indicates that regular physical activity is well-known for providing essential health benefits and preventing chronic and non-communicable diseases, including heart disease, stroke, diabetes, and several cancers (1). Even so, several studies have proposed that intensive and unaccustomed exercises can lead to impaired muscle function, athletic performance, and recovery (2, 3). High intensity and endurance exercises lead to an imbalance between oxidants and antioxidants in favor of the oxidants defined as exercise-induced oxidative stress (EIOS) (4). EIOS and the high level of reactive oxygen species can contribute to muscle damage (2, 4). Besides, it should be noted that prolonged muscle contractions can result in a condition called exercise-induced muscle damage (EIMD). EIOS and EIMD are the influencing factors that result in muscle soreness, localized swelling, increased levels of creatine kinase (CK), lactate dehydrogenase (LDH), myoglobin (MYO), and inflammatory markers including C-reactive protein (CRP), Interleukin 1 (IL-1), Interleukin 6 (IL-6), TNF-α (3, 5) which lead to poor athletic performance. Considering the point that oxidative stress is the leading factor of the mentioned phenomenon, there is a growing interest in the use of antioxidant supplements by physically active individuals. Also, it seems that supplements with antioxidant and anti-inflammatory properties will provide more favorable effects. Tribulus terrestris (TT) is one of the herbal supplements with mentioned properties.
TT is a native plant of Iran classified in the family Zygophyllaceae (6, 7). It can be found in a wide range of warm and humid regions such as the Mediterranean, Asia, Australia, Africa, and the warm areas of Europe (8) and contains a high concentration of active ingredients such as sterol saponins, flavonoids, tannins, terpenoids, phenol carboxylic acids, and alkaloids. The leaves, seeds, and fruits of TT are used for therapeutic purposes; however, studies indicate that the highest amount of active ingredients are found in its fruit (6, 8). Studies concentrating on the therapeutic effects of TT have assessed its potential effects regarding sexual enhancement (9), fertility (10), urinary tract stones (11, 12), diabetes (13, 14), cardiovascular disease (15, 16), antioxidant properties (17, 18), anti-inflammatory properties (19, 20). Therefore, a wide range of clinical studies has assessed TT effects. Still, considering the point that there are few randomized clinical trials on the effect of TT in athletes (21) and physically active individuals (22) and also there is no randomized clinical trial in recreational runners; this study has been designed to assess the efficacy of TT on the nutritional, oxidative, inflammatory, and anti-inflammatory status and sport performance of recreational runners.
The present study is designed to determine the effect of TT supplementation on the nutritional, oxidative, inflammatory, and anti-inflammatory status and sport performance in recreational runners.
To assess the effect of TT supplementation on malondialdehyde (MDA), Total antioxidant capacity (TAC), Superoxide dismutase (SOD), hs-CRP, IL-6, IL-10, CK, LDH, and sport performance of recreational runners with TT supplementation and high-intensity interval training (HIIT) training.
To assess the effect of TT supplementation on nutritional status (energy and macronutrient intake), insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), and body composition of recreational runners with TT supplementation and HIIT training.