A Pilot Study on Cannabidiol (CBD) and Eccentric Exercise: Impact on Inflammation, Performance, and Pain

Cannabidiol (CBD) is a non-psychoactive cannabinoid purported to reduce symptoms of discomfort. Individuals are now using CBD to treat symptoms of multiple sclerosis, seizures, and chronic pain. Animal models indicate that CBD may be effective at reducing inflammation post fatiguing exercise. However, little evidence is available to evaluate these findings in humans. Therefore, the purpose of this investigation was to evaluate the impact of two doses of CBD oil on inflammation (IL-6), performance, and pain after an eccentric loading protocol. Participants (n = 4) participated in three conditions (placebo, low dose, and high dose), in this randomized, counterbalanced design. Each condition took 72 hours to complete, with a 1-week washout period between conditions. At the beginning of each week, participants were subjected to a loading protocol of six sets of ten eccentric only repetitions in the single-arm bicep curl. Participants consumed capsules of either a placebo, low dose (2mg/kg) or high dose (10mg/kg) of CBD oil immediately following the session and continued every twelve hours for 48 hours. Venipunctures were taken before exercise and repeated at 24, 48, and 72 hours post exercise. Blood samples were centrifuged for 15 minutes in gel and lithium heparin vacutainers. Plasma was separated from cells and stored at -80° until analysis. Samples were analyzed using an immunometric assay for IL-6 (ELISA). Data were analyzed using a three (condition) by four (time) repeated measure ANOVA. There were no differences in inflammation between conditions (F(2,6) = 0.726, p = 0.522, n_p ² = 0.195) or across time (F(3,9) = 0.752, p = 0.548, n_p ² = 0.200), handgrip strength between conditions (F(2,6) = 0.542, p = 0.607, n_p ² = .153) or across time (F(3,9) = 2.235, p = .153, n_p ² = .427), or bicep curl strength between conditions (F(2,6) = 0.675, p = 0.554, n_p ² = .184) or across time (F(3,9) = 3.513, p = .150, n_p ² = .539). There were no differences in pain between conditions (F(2,6) = 0.495, p = 0.633, n_p ² = .142), but there was a difference across time (F(3,9) = 7.028, p = .010, n_p ² = .701). There were no significant interactions to note. Although there was no statistical significance between conditions (likely due to the low sample size), there was a visible increase in IL-6 48 (4.88 ± 6.53) and 72 hours (3.12 ± 4.26) post exercise in the placebo condition which was not observed in the low (48: 0.35 ± 2.22; 72: 1.34 ± 5.6) and high dose condition (48: 1.34 ± 1.34; 72: -0.79 ± 5.34). Future investigations should consider implementing eccentric resistance training across a larger portion of the body to improve ecological validity of the exercise. A larger sample would reduce risk of researchers committing a type II statistical error and give strength to detecting differences between conditions.