Hey Steve,
You asked about when to add Tabata training and there is no good answer. I added it because I wanted to lose some weight and get my heart stronger. So far it hasn't hindered my progress and I'm still able to maintain weekly gains. I work full time and have an 11month old (at 40...I never knew that parenting was a young man's game...lol) so I don't always get the best rest I could but I always make sure and eat a lot.
I would say that if you want to add the Tabata or other cardio then you should but be prepared to need just a bit more food. I also don't run at all (well, I sprint around with my dog) so my legs get worked some during my cardio but not really that much. My cardio is also short. My complexes only take maybe 15 minutes or so and my Tabata session is 4 minutes.
Hope that helps,
james


