off day cardio help please

[Agressor]

On my days off from training, i want to do some cardio, like 45-1 hour bike ride, or a run or something. so its 3 days wieghts, 3 days 45-1 hour cardio, and 1 day off, it that ok?? aslong as i replace cals......Im not trying to lose weight, and not really body fight, i wanna build muscle.

Will the cardio break down muscle?

 

[Arnold]

if you're trying to build mass doing that much cardio will hinder your gains.

 

[Agressor]

how badly will it slow growth down?

im not trying to be HUGE!!! in size, i jst wanna be pretty well build (a good build, not gorilla size) and i wanna be fit, and that requires cardio. I want to be able to compete in triathlons and big swimming events in the sea, in summer. But jst friendly not hard-core. And next year at school im doing Outdoor education, which involvues quite alot of cardio (one day we have to do rowing, biking and running which sould take us 6-7 hours).

im gonna spend the next month jst on building before school starts (Im in New Zealand) and then when school starts ill have to do cardio on days off.

What do you guys think?