Effects of oral capsaicinoids and capsinoids supplementation on resistance and high intensity interval training: A systematic review of randomized controlled trials

Abstract

Oral capsaicinoids and capsinoids supplementation has been studied recently for a plausible ergogenic impact on sports performance. However, non-aggregated literature has focused on the impact of this substances in healthy humans' performance. The aim of the present systematic review was to explore the effects of capsaicinoids and capsinoids on resistance training (RT) and HIIT exercise. Studies searches were performed in the PubMed/MEDLINE, Scopus and Web of Science electronic databases. Studies where healthy subjects consumed capsaicinoids or capsinoids acutely or chronically compared to placebo before a RT or HIIT intervention were included. The methodological quality of the included studies was assessed with PEDro checklist. A total of 7 excellent-good quality placebo-controlled trials (i.e., 5 RT and 2 HIIT experiments) were included. The most prevalent protocol used capsaicin (i.e., 6 capsacin and 1 capsiate studies) and acute (i.e., 5 of 7 interventions) supplementation designs. Positive effects were only noted for capsaicin in repetitions until failure (+14.4 to +21.7%), total weight lifted (+13.0 to +23.3%), perceived effort (-6.4%), fatigue index (+15.0%) and peak torque (+6.1%) compared to placebo. Neuromuscular HIIT variables (e.g., total and medium sprint time) were not highly affected by capsaicin except the time to reach 90% VO2 peak (+61.2%) and the number of efforts performed (+14.7%). Collectively, our findings suggest a positive effect of 12 mg of capsaicin on strength endurance, total weight lifted and perceived effort variables in healthy males after acute (i.e., 45 minutes pre-exercise) supplementation.

Effects of Microfiltered Seawater Intake and Variable Resistance Training on Strength, Bone Health, Body Composition, and Quality of Life in Older Women: A 32-Week Randomized, Double-Blinded, Placebo-Controlled Trial

“…Dietary supplements are legal, free-sale nutritional complements that in conjunction with a healthy diet can improve well-being and/or sports performance [ 8 , 9 ]. In this concern, resistance training (RT) and specific nutritional supplementation (e.g., calcium, vitamin D, creatine, and magnesium) have elicited positive results as non-pharmacological strategies to prevent and treat the abovementioned long-term conditions [ 10 , 11 , 12 , 13 , 14 ].…”

Effects of different phenylcapsaicin doses on resistance training performance, muscle damage, protein breakdown, metabolic response, ratings of perceived exertion, and recovery: a randomized, triple-blinded, placebo-controlled, crossover trial

“…Recently, sports nutrition research has focused on the discovery of new active compounds which may be able to improve high-intensity training in different modalities [ 3 , 4 ]. Within this context, capsaicinoids have emerged as a plausible ergogenic aid for strength conditioning and high-intensity sports [ 5 , 6 ]. Capsaicinoids are a group of compounds naturally found in spicy chili peppers which are characterized by their vanilloid structure [ 7 ].…”

“…On the other hand, capsaicin seems to enhance sport performance by reducing ratings of perceived exertion and perceived discomfort while improving mechanical performance (e.g. total volume load) [ 5 , 11 ].…”

“…The feedback from afferents III and IV could directly or indirectly reduce motoneuron firing and motor unit recruitment [ 14 , 15 ]. In this sense, the TRPV1 content of these nerve fibers (mainly in group IV afferents) has been proposed as a target for enhancing physical performance by using capsaicin [ 5 , 6 , 16 ]. Thus, as a TRPV1 agonist, capsaicin could improve muscle contraction by increasing the perceived heat analgesia and the release of calcium from the sarcoplasmic reticulum, which are linked to motor units function [ 5 ].…”

“…To date, capsaicinoid supplementation has mainly been tested on sports performance with encapsulated capsaicin formulations [ 5 ]. Purified acute (i.e.…”