Credibility: As many fitness centres may require their trainers to have certification from credible and recognised organisations, the most important thing a trainer needs is a list of happy, successful clients; know if he or she has good referrals.
Good listeners: A good trainer does more listening than talking, asks the right questions and focuses intensely on the answers. They should ask about your goals and expectations hence adjusting them appropriately.
Positivity: Even when you are struggling, a good trainer will stay positive in addition to encouraging you since fitness is about progress not perfection. Look out for someone who will push you harder.
Track progress. As a client, do not be afraid to ask your trainer for concrete evidence of your progress. This can be done through the weighing scale, range of motion, sleep quality, among others.
Adjustment: If you do not feel the impact of a given workout, communicate with your trainer who should be in position to give you a better alternative workout.
Warm-up and cool down: The best trainers know how to design a thorough, yet time efficient warm-up to prepare the body for the workout and a good cool down that relaxes the muscles after working out.
They admit what they do not know: Nobody knows it all, and the best trainers are not afraid to admit it. In cases where they do not know, they will refer you to someone else or ask for time to do research.
Avoid a trainer who claims to know everything because they might cause harm.