First, numerous studies have shown that combining aerobic and anaerobic exercise is less efficient than just doing anaerobic excercise. Combining the two makes the exercise worse, not better.
Second, assuming you can do at least 20-30 crunches in one set, (normal) crunches are basically a waste of time as the resistance is too small.
Third, that you feel you've had a good workout at the time you're doing it doesn't mean it is. For instance, sweat, tiredness, or an elevated heart rate isn't even an indication that you've actually had a good workout.
Just lift heavy weights. That's the most efficient use of your time and effort. Everything else you do in a gym can be good for the purpose of keeping you motivated, or whatever, but it's all quite a bit less efficient than just lifting weights. Keep it under 60 minutes, followed by intake of protein and carbs. The science behind this is well established.
Second, assuming you can do at least 20-30 crunches in one set, (normal) crunches are basically a waste of time as the resistance is too small.
Third, that you feel you've had a good workout at the time you're doing it doesn't mean it is. For instance, sweat, tiredness, or an elevated heart rate isn't even an indication that you've actually had a good workout.
Just lift heavy weights. That's the most efficient use of your time and effort. Everything else you do in a gym can be good for the purpose of keeping you motivated, or whatever, but it's all quite a bit less efficient than just lifting weights. Keep it under 60 minutes, followed by intake of protein and carbs. The science behind this is well established.