Charr, this may just be nomenclature but I am not sure what you mean by training at maintenance but I assume you mean maintaining calories. You should never train (workout) to maintain. It is a waste of time. Workout to grow, not maintain, even if you are working out at maintenance calorie consumption.
At your age, get a full hormonal blood workup, not just T. Insulin sensitivity, thyroid output, adrenal gland activity, etc. can all be contributing factors that may affect your results that are easily adjusted with diet and/or medication. Also have your lipid levels checked so you don't get on a diet that may be harmful to your overall health. Once you have that info, you are then ready to design a program for maximum results. Right now, none of us can really steer you in the right direction except based on average generalizations and we all know that averages do not appear in real life, e. g., "the average family has 2.2 children". The blood work can be a few hundred dollars if you have no insurance but could save you years of frustration in the gym.
At your age, get a full hormonal blood workup, not just T. Insulin sensitivity, thyroid output, adrenal gland activity, etc. can all be contributing factors that may affect your results that are easily adjusted with diet and/or medication. Also have your lipid levels checked so you don't get on a diet that may be harmful to your overall health. Once you have that info, you are then ready to design a program for maximum results. Right now, none of us can really steer you in the right direction except based on average generalizations and we all know that averages do not appear in real life, e. g., "the average family has 2.2 children". The blood work can be a few hundred dollars if you have no insurance but could save you years of frustration in the gym.