Hiring a personal trainer may be the best investment you make all year. Studies show that the likelihood of meeting any goal—and fitness goals in particular—skyrockets when you map out specific strategies and find someone to keep you accountable. “So many times people have tried working out on their own and they’re not getting results,” says Nick Clayton, personal training program manager for the National Strength and Conditioning Association (NSCA). “A personal trainer can really turn that around.” Here’s how to find the right one for you.

Plan for an Interview

Always interview a trainer before committing—that’s your chance to ask about their education, experience and training philosophies, and to see if your personalities click. A good trainer will ask you about your goals and preferences, so think through what you’re looking for beforehand. “If the trainer talks about ‘I, I, I’ instead of about you, that’s a huge red flag,” Clayton says. “It shouldn’t be about their fitness accomplishments, but about what they can do for you.” Another tip from Clayton: After the interview, work out at the gym and watch the trainer in action with another client to see how attentive he or she is to a client’s needs.

Go Certified

Roughly 11 accredited organizations certify personal trainers; the NSCA and the American College of Sports Medicine (ACSM) have the most stringent requirements, says Clayton. Certification ensures trainers have adequate training themselves and requires ongoing education to keep certifications current. Trainers can also get specialized certificates for marathon or other sport-specific training, so ask about those if you’re interested.

Consider What Might Derail You

Is diet a weakness in meeting your goals? Find a trainer who is also certified in nutrition. Is time or convenience an issue? Hire an online trainer so you can work out at home or a trainer who is also a life coach. Short on cash? Consider semi-private (two or three participants) or group (four to 10 participants) sessions.