There is literature to support doing CARDIO before or after a WORKOUT.
THE QUESTION IS WHAT IS THE GOAL? For most of us, the goal is to LOSE WEIGHT and gain STRENGTH.
Doing cardio AFTER a weight training session is the best option!
The reason for this due to glycogen depletion. During a weight training session, the muscles get depleted of glycogen (sugar). Glycogen is used as an energy source for exercise. When glycogen is depleted BEFORE cardio, FAT is used as an energy source.
In fact, studies have shown that doing CARDIO AFTER a weight training session BURNS MORE FAT in the first 15 minutes compared to doing CARDIO BEFORE your workout.
Ideally, it would be nice to schedule days in the week where we just do cardio.
Most of us do not have that type of time. In order to MAXIMIZE your GYM TIME, try INSERTING CARDIO into you WEIGHT TRAINING session.
For example, run a circuit of:
400 meter jog 15 push-ups 10 crunches
Do 4 - 5 sets of this circuit to maximize your time at the gym by BUILDING MUSCLE and TORCHING FAT!