If you use straight sets during your weight training sessions, reducing the rest between sets each week in 15 second increments; from 90 to 30 seconds, will actually allow you to burn more fat AND build more muscle (Souza-Junior. 2011). The subjects did start at 2-minute rest intervals, but I’ve adapted this info from the 60-90 second rest intervals I normally recommend, to make your workouts even faster. The details of this method can be found here.
If you want to do more of a full body workout, just three days per week, you can do what is called; Fast Paced High-Resistant Explosive Circuit Weight-Training. In this protocol (Alcarez. 2011), the training sessions only took about an hour and the circuits can be found here.
Either of these methods should take your training time to less than 3 hours per week, AND you’ll get better results. Variations of both of these methods have worked wonders for me, and hundreds of others that have asked for my advice.
You can adapt this info into your current program, but remember the principle; doing more work in less time.
This is one reason why sprinters are more muscular than marathon runners.
The pain is shorter, but a better body is with you for life.
Are you too busy now?