The Key is quality not quantity.
As far as weight training goes , You should do only 12-15 sets for Large Muscle groups (Back, Chest, Legs) and 6-8 sets for smaller muscle groups. The key is that you do every set to maximum Failure and never do any weight that you can not do at least 6-10 reps. For example if you can do arm curls with 60 pounds for 8-10 reps , Don't waist energy working up to 60 pounds
( doing 1 set at 30 , 1 at 40 , 1 at 50 ), after the initial warm up get right to 60 pounds and do 3-4 sets to maximum failure.
I do only 20 minutes of cardio per week and that is only a day after my heavy leg workout, it is to help me stretch and get rid of soreness, But My weight training sessions are 30-45 minutes at very high intensity and my heart rate is in the fat burning zone throught entire workout.
I personally don't think anyone have the energy or stamina longer then 45-60 minutes for a High intensity workout where your heart ratae is in the "Fat Burning Zone". If anyone believe they can last longer then 45-60 minutes I would love to take them through one my training sessions

itm/godfather, check out jrs new pics

hmm this is interesting. so if you are in the fat burning zone for 20-30 min and you have the time to work out more, should you do more weights or what?

As long as your heart rate is in the fat Burning Zone (65% to 75% of your maximum heart rate), 30 minutes of cardio is enough. People take 20-30 minutes to warm up and get their heart rate in Fat burning zone. If you are doing weight training too , i recommend doing cardio after weight training , this way your heart rate is in the recommended "fat burning zone" when you start and 25-30 minutes should be enough. While doing weight training try to cut your rest in between sets to less then 45 seconds, This would help greatly in making sure that your heart rate is in Fat Burning zone throughout your workout.

-> ... At a lower % of max heart rate (65%), a larger percentage of calories burned come from fat than at a higher heart rate (75-85%). HOWEVER, despite the percentages, you will burn more total calories and therefore more total fat calories at a higher heart rate. *(220 minus age being max)* Also, your individual goals dictates the amount & intensity of cardio you should be doing!

Heart-rate target levels is the key, essentially.
Low intensity cardiovascular exercise, burns a much greater percentage of stored fat than high intensity exercise. If you want to primarily burn bodyfat, you want to stay at a lower heartrate. You'll burn significantly more fat performing 45 minutes of cardio at 50%-60% of your age predicted heart rate maximum, than you will doing 20 minutes of cardio at 85%. As heart rate increases, you burn less fat for fuel, so I try to keep your heart rate at about 50-60% of your age predicted max heart rate.