This is a common question a lot of trainers get. First of all the fact that you are doing both types of training is great . However, doing your strength training first is preferred for a couple of reasons. First, your muscles are fresh and at their peak at the beginning of your workout allowing you to max out your muscles to their full potential. For instance, if you run or stair climb before strength training your legs, the leg muscles are already somewhat fatigued so you won’t be able to do as many reps or as much weight. Secondly, there is some fat burning benefits to doing cardio last. After about 20-30 min of exercise your body starts getting a lot of its energy from fat- ever heard of the fat burning zone? So cardio after strength training will help burn more fat. Lastly, I personally think it just feels better to work my muscles before and end with a good sweat.