There are many synonyms for the phrase "trains in." Some of the most common ones include educates, instructs, coaches, teaches, mentors, guides, tutors, and primes. Each of these synonyms refers to the act of preparing or providing knowledge or skills to someone in a specific area. For example, a coach trains in athletic skills, while a mentor trains in life skills. Other synonyms may include drilling, preparing, grooming, schooling, and readying. However, each of these words has a slightly different connotation, so it is essential to choose the exact synonym that best fits the context and desired outcome.