There is a high prevalence of chronic pain in our society, which is detrimental at an individual and country level. Cannabidiol (CBD) has been proposed as a promising treatment for chronic pain, although more high-quality studies are needed in this area. On the other hand, triathlon, running, cycling, and swimming are sports modalities that have an increasing professionalism and importance, albeit not exempt from injuries.

The main goal of this study is to assess the effectiveness of a topical treatment for recurrent chronic pain caused by tendinopathies with a cream containing CBD in triathletes, runners, cyclists, and swimmers. Consequently, the research question for this study is the following: Can the CBD cream be effective in treating chronic pain? The investigators hypothesize that the cream will be able to affect the pain, both in the short and the long term.

The study will be interventional, with a crossover, randomized, and double-blinded design. Two groups of participants will be generated, as well as two treatment options (CBD cream, and a similar one without the CBD). The subjects will apply one of the treatments for one month, followed by a wash-out week without any cream application, and another month with the other treatment. During these weeks, different parameters will be controlled via online questionnaires.

The analyzed variables will include the following: Chronic pain, acute pain, wellness, perceived exertion, quality of life, and satisfaction with the treatment. Different statistical tests will be applied to the collected data, comparing their means and correlations to infer the results.

Inclusion Criteria:

• Being a federated triathlete, runner, cyclist, or swimmer.
• Being 18-70 years old.
• Having chronic pain (present at least 3 months before the beginning of the study).
• Having a diagnosis of patellar, Achilles, or iliotibial band tendinopathy for the lower extremities, and/or shoulder rotator cuff or biceps brachii tendinopathy for the upper extremities.
• Training any modality of triathlon, running, cycling, or swimming 4-5 days per week with a minimal training volume of 8 hours per week.
• Having at least 1 year of experience training in triathlon, running, cycling, or swimming.
• Providing at least 80% of the needed data for the study.

Exclusion Criteria:

• Pregnant women.
• People allergic to any of the ingredients of the creams used.
• People with skin injuries in the zones in which the cream has to be applied.
• Using any other pain treatments. Those who use them before the study can still participate if they stop their usage 1 week before the beginning of the study.

Both creams will have identical containers (a neutral white tube), with the only difference being that they will be tagged with the letter "A" or "B" (without any additional information on any part of the container).