Your original question was phrased in such a way that my first impression was that teaching Crossfit is a new occupation for you. However, if you are already working as a personal trainer or fitness coach and are adding the Crossfit certification to increase your range of skills and services that you offer to customers, then the cost of this certification would be a deductible expense. If you are an employee, the expense would be an Employee Business Expense, deductible on Form 2106. If you are self-employed, the expense can be taken on Schedule C.
