The neverending question whether to do weights beefore cardio seems to never have an answer. Everyone will tell you something different and will have a specific set of reasons why they are correct in their thinking.
Experts are definitely torn on this issue. The majority of fitness experts or want to be experts will tell you to do cardio after weight training because if you do cardio first, you use much of the energy source strength training and your muscles are fatigues before their most strenuous activity. That is what most weight trainers who use Qnet recommend as well. On the other hand, this holds true that if you do strength training first, you can deplete your muscles’ stored carbs and then will enhance fat burning during your cardio sessions due to the lack of available sugar for your fuel.
There really is no credible or concrete research that proves this theory and in general, what should be done first all comes down to your exact fitness goals. For example, if your main goal is to increase your aerobic endurance or lose fat, then you should perform cardio before weights. On the other hand, if your primary goal is to strengthen and build muscle, then you should do strength training first. Regardless of specific goals, you must perform the exercises that are most crucial to reach your goal first so you are not too fatigued.
A good rule of thumb is to remember no two people are the same. Do what works for you!