Personal view: cardio very over rated for long lasting fat loss. Too much cardio actually can have a muscle wasting effect on some people, loss of muscle mass that was worked so hard for. For what their worth, a few suggestions for fat loss, rather than endless time on the treadmill.
Try running on heavy beach sand and watch the difference that makes on the body. 20 minutes should do it. If running on sand hills, 10 minutes should do it. Run in bare feet.
Suggest also interval training. The Tabata method is a good start, 8 to 12 minutes will do it. Many other forms of interval workouts.
Increase the pace of a workout, reducing rest time between sets and exercises. Most guys are just stroking it during gym time..... hanging out, rather than really working out. 45 seconds , as an average time between sets. 60-90 seconds between squats, DL's or cleans.
Checkout the PHA system of training......stamina without a doubt. Also circuit training, the correct way.
Some BB'ers will run 20 to 45 minutes after a good BB'ing session. If wanting serious muscle building results after a serious workout...don't run right after. Save that for another time. Want to keep the pump and the blood, (with all the bodies natural muscle building chemicals release from that workout) in the area of the body part just worked....than don' run.
Weight training based workouts can do much to greatly increase the endurance and fat loss, and still build solid muscle mass.
Good Luck.