Does using a blow dryer on your hair after using a moisturising shampoo and conditioner defeat their purpose?

I use Garnier moisturising shampoo and conditioner because it leaves my hair SOOO soft and silky and shiny. I used to air dry a lot, but it ALWAYS leaves my hair so lifeless, flat and curls every which way. Now I usually blow dry. I notice my hair feels kind of different after I blow dry than it does when I air dry.





I know heat is damaging to your hair, but how bad is it to blow dry when you use a moisturising shampoo and conditioner? Does it defeat their purpose?Does using a blow dryer on your hair after using a moisturising shampoo and conditioner defeat their purpose?
before i use my hair dryer after washing i spray on a heat-protectant spray by nexxus =)