When you walk into a gym, you see people doing one of two things: strength training or cardio (there is stretching too, however that isn’t a relevant part of this post). What order is best, you ask? Strength train first, then do your cardio.
Here is why: In order for your body to use your fat as fuel for exercise, your body has to burn through your glycogen stores first (glycogen stores are where the majority of those carbs you eat end up in your body). By doing strength training first, your body burns through most of your glycogen stores at a higher level than it would doing cardio. That way, by the time you get to the cardio part of your workout, your body will be using your fat stores to get through it. Ultimately, burning more fat than it would doing your cardio first. So simple!