Bodybuilders strive to increase muscle mass and reduce body fat as much as possible. The best way to achieve this is to train hard with weights and do cardio to burn off calories and cut fat. Unfortunately, strength and endurance exercise can interfere with each other. An age-old question is should you do cardio or weights first? Circumstantial evidence supports both training sequences. Lifting weights and cardio both raise metabolic rate. Cardio and weight training cause fatigue, so if you run on the treadmill first, the quality of your weight-training program will suffer – and vice...