Does CBD improve recovery from exercise? Original paper

Cannabidiol (CBD) is one of over 100 cannabinoids found in the Cannabis sativa plant and is the second most abundant after THC. CBD has shown promise as a treatment for a variety of conditions (e.g., epilepsy) and is becoming increasingly popular among athletes for its purported anti-inflammatory effects. Does supplementing with CBD improve recovery from resistance exercise?

In this randomized crossover trial, 24 current or previous female collegiate athletes (ages 18–26) completed 10 sets of 10 repetitions of unilateral eccentric leg extensions and supplemented with either 5 mg per kilogram of body weight of CBD (in pill form) or a placebo at 2 hours prior to exercise, immediately after exercise, and at 10 hours after exercise (15 mg per kilogram of body weight total, range of 672 to 1,224 mg of CBD). There was a washout period of about 4 weeks between conditions.

Researchers collected blood samples and assessed subjective fatigue 2.5 hours before exercise and at 4, 24, and 48 hours after exercise. Physical performance was also assessed at 24 and 48 hours after exercise.

The outcomes of interest were interleukin 6 and interleukin 1-beta (markers of inflammation), interleukin 10 (a cytokine with anti-inflammatory properties), myoglobin (a marker of muscle damage), subjective fatigue, vertical jump height, dynamic strength of the quadriceps (measured as peak torque during concentric leg extensions on an isokinetic dynamometer), and isometric strength of the quadriceps.

There were no differences between groups for any of the measured outcomes at any time point.

This study recruited only female athletes, so the results may not be generalizable to male athletes.

Exercise — particularly when it’s strenuous, unfamiliar, and/or involves an eccentric component — causes muscle damage, which initiates an inflammatory response and impairs muscle function. This inflammatory response is necessary for muscle recovery and adaptation, but excessive inflammation can result in prolonged muscle soreness and suboptimal performance. Athletes are not always guaranteed at least 48 hours of rest between bouts of training or competition, so there is immense interest in strategies that can help mitigate excessive inflammation and improve recovery.

In a number of rodent studies, CBD was found to inhibit the production of inflammatory cytokines and reactive oxygen species and stimulate the production of anti-inflammatory cytokines.^[1] CBD’s effects on inflammation seem to be a result of its ability to modulate (directly or indirectly) CB2, TRPV1, PPAR_γ, and adenosine A_2A receptors.^[2]

CBD’s popularity has soared recently because it was removed from the World Anti-Doping Agency’s list of prohibited substances in 2018. The results of a survey published in 2020 showed that among 517 professional rugby players from 25 teams, 26% of respondents were either currently using or previously used CBD. The most common reason for using it was to improve recovery and reduce pain.^[3]

Use of CBD among rugby players

CBD use

8% Currently use cannabis | 18% Previously used cannabis

Reason for use

80% Recovery/pain | 78% Sleep | 32% Anxiety | 14% Other medical conditions (e.g., concussion)

Source of CBD information

73% Internet | 61% Teammates | 16% Team nutritionist | 4% Other team staff members

Despite mechanistic evidence supporting the efficacy of CBD for reducing inflammation and a common notion among athletes that CBD enhances recovery, this study did not find evidence of these benefits. What about other studies?

A randomized controlled trial by Hatchett et al. published in 2020 assigned resistance-trained participants (average age of 22) to ingest a placebo, medium-chain triglyceride oil, or a CBD oil containing medium-chain triglyceride oil and 16.67 mg of CBD after performing 4 sets of 10 repetitions with 80% of their 1-repetition maximum (1RM) on the barbell back squat.

The results suggest that CBD improved muscle recovery, as indicated by perceived muscle soreness scores (measured using visual analog scales) returning to preexercise values more rapidly in the CBD group.^[4] However, there are some concerns about the statistical methods that the researchers used. Additionally, perceived muscle soreness before and immediately after the exercise session were notably higher in the CBD group than the other groups, so it’s unclear how much, if at all, of an effect CBD had on muscle soreness.

A randomized crossover trial by Cochrane-Snyman et al. published in 2021 assigned untrained men (average age of 22) to ingest either 150 mg of CBD (in gel capsules) or placebo after performing 6 sets of 10 repetitions of eccentric biceps curls and at 24 and 48 hours afterward. There were no differences in perceived muscle soreness and maximal voluntary isometric contraction between conditions immediately after exercise or 24, 48, and 72 hours later.^[5]

Lastly, a randomized crossover trial by Isenmann et al. published in 2021 assigned resistance-trained participants to ingest either 60 mg of a special CBD formulation called “solubilistat” or a placebo immediately after a workout consisting of 3 sets of 12 repetitions of barbell back squats at 70% of 1RM and 3 sets of 15 repetitions of drop jumps from a 45 cm box. It was found that at 72 hours after exercise, but not 24 or 48 hours after exercise, supplementation with CBD had a small positive effect on myoglobin and creatine kinase levels and barbell back squat 1RM.

A notable difference between this study and the summarized study is that the outcomes were assessed at 72 hours after exercise, which suggests that it may take at least 72 hours for the potential benefits of CBD to manifest. Although this hypothesis was not supported by the Cochrane-Snyman study, it’s worth noting that different populations (untrained vs. resistance-trained) and muscle groups were studied, which could have influenced the results.

The studies that have investigated the efficacy of CBD improving recovery from exercise have varied in the population studied, the protocol utilized to induce muscle damage, the dose of CBD, and the method of CBD administration. Nonetheless, the available evidence collectively suggests that CBD does not improve recovery from exercise or has very little effect. That said, the studies conducted so far have been acute trials, so it remains unclear whether longer-term supplementation with CBD improves recovery from exercise. Further randomized controlled trials are needed to confirm whether there is a benefit to supplementation with CBD for improving recovery from exercise.