It's time to start aligning your workout with your goals.
Are you trying to build muscle mass and lose body fat? Are you striving to build up your stamina and cardiovascular system?
When you aim to build better stamina and a stronger cardiovascular system, refrain from frequent weight lifting.
Specific days dedicated to weightlifting are significant, but it's important not to do both on the same day. For example, if you run 3 miles one day, the next week, run about 5 to 10% longer or more. Save at least one day to strengthen your muscles with weight training. Every week after that, continue building at least 5 to 10% more in the previous week. Eventually, your performance will be substantially better.
If your goal is to build muscle mass, you should leave cardio for the last thing you do.
It's probably your habit to go to the gym and get warmed up by jumping on the treadmill or the step machine. Unfortunately, you're hurting yourself in terms of reaching your goals. The energy you use for your cardio is better suited for strength training. You can jump-start your cool-down phase with cardio after strength training. It's a great way to ease your body into low pace everyday movement.
Keep in mind that exercise performance is a science. Our bodies function in a particular way, so continue learning and building a strategy to get the needed gains.