Yes! Do not start training clients without being insured. You never know what might happen during your sessions with them, so you must be covered. Spend the money and get the insurance, because it will cost a lot more if something happens to any of your clients during their sessions. Insurance is inexpensive and necessary. If you train clients in a condo building gym or if you rent a space for sessions or classes, the building owner or association may also require you list them as an additional insured, so always ask about requirements in those situations. You can check the IDEA web site for more information on insurance.