#1 Check the degree and certification of the trainer. It is important for them to have knowledge in the field of exercise physiology to have the ability to create an exercise program tailored to the individuals goals. A field related certification typically ensures the knowledge and proffesionalism of the individual. I reccomend American College of Sports Medicine (ACSM), National Strength and Conditioning Association (NSCA), or Americian Council on Exercise.

#2 Your personality should jive with the personality of the trainer. Your workouts should be fun and enjoyable. If you don't have good chemistry with your trainer, you will dread the workouts and be less likely to continue.

#3 It is important for your trainer to have practical experience. If the trainer practices what they preach, they will create more effective workouts.