anaerobic vs catabolic state

This very much sounds like a very simple question, but i can't find a definitive answer...
 
My aims are toning, and to build muscle (not to a bodybuilding level) - and i am not particualrly over-weight, just lacking definition.
 
Is it a case of ignoring the cardio completely? At present i do a 10-15min warm up on running/cross trainer, weights circuit, and then a 10 min sprint session either on running machine or rowing machine (90 sec 60%, 30 sec 100%, 60 sec 40% recovery). Is this cardio enough to create a catabolic state which will block 'growth'?
 
 

Cardio doesn't really block growth - it's a bit of bro science mythology.
 
In extreme circumstances it's technically possible but the crucial factor is diet. If you're in large defecits then you can force a catabolic state, in fact, long term this can have serious detrimental effects (a lady I know actually lost teeth becasue she got so low on calorie intake whilst maintaining high levels of cardio).
 
generally speaking, if you are on or around your calorific requirements you won't hinder growth from doing a bit of cardio, especially if the cals are clean.  In fact, a counter argument says that the metabolic spikes you get from cardio could actively help the body attain hypertrophy if supported by the correct diet.