Author(s): SCHOUTEN, M., RAMAEKERS, M., PEERS, K., THOMIS, M., DALLE, S., KOPPO, K., Institution: KU LEUVEN, Country: BELGIUM, Abstract-ID: 2352

INTRODUCTION:
Strenuous exercise causes microstructural muscle damage, leading to delayed onset muscle soreness and temporary performance loss. Improved recovery can increase training efficiency and performance in athletes, which is why novel recovery-enhancing strategies are of interest. Supplementation with cannabidiol (CBD), the non‑psychoactive compound of the cannabis plant, that exerts anti‑inflammatory and analgesic effects, might be a promising strategy. Yet, human evidence for its recovery‑enhancing potential is limited, and its effects on a muscle‑molecular level remain unknown. Therefore, this study evaluated the effect of CBD supplementation on functional performance and molecular responses in skeletal muscle tissue to a muscle damaging exercise (MDE) bout.
METHODS:
Ten healthy male participants completed this randomized, double-blind, placebo-controlled, crossover study in which they performed an acute bout of MDE (24x10 eccentric contractions of the knee extensors on an isokinetic dynamometer). At baseline, 24, 48, 72, and 120h following MDE, maximal isometric, concentric and eccentric voluntary contraction, jump height and perceived muscle soreness were measured. Muscle biopsies were collected at baseline and 24h following MDE and were analysed for relative protein expression by western blot. Participants received either 200mg of CBD per day or an appearance-matched placebo for nine consecutive days, beginning immediately after baseline measurements (-96h pre‑exercise) and continuing until the evening before the final test session (120h post‑exercise).
RESULTS:
Isometric (-19.5%), concentric (-28.9%) and eccentric strength (-28.7%), along with squat jump (-9.6%) and counter movement jump height (-8.2%), decreased following MDE (Ptime < 0.0001), without differences between conditions. The drop in performance was accompanied by an increase in perceived muscle soreness (Ptime < 0.0001). Furthermore, MDE increased the expression of the myogenic marker myogenin (+685.5%; Ptime = 0.0011) and of the anabolic marker p-mTOR (+61.0%; Ptime = 0.0001). In addition, LC3B‑I levels increased (+40.6%; Ptime = 0.0295), but other markers of autophagy and inflammation (LC3B‑II, p62, ATG5/12 and CD68) remained unchanged. Besides higher overall expression of p-mTOR in the CBD condition (35.5%; Pcondition = 0.0439), no differences in the expression of molecular markers were observed between conditions.
CONCLUSION:
Within the context of this study, CBD supplementation did not improve muscle soreness, muscle strength and jump performance following MDE. In addition, CBD supplementation had no effect on molecular markers of anabolism, autophagy, inflammation or regeneration in response to MDE.