You should shower when you sweat.
Also, what is very healthy for your circulation is doing the Warm Cold Shower.
You shower in warm water for 30 seconds, then cold water for 30 seconds, and switch like that a few times.
Its not a bad thing to take a shower, water is life after all. That said there are a couple of things that you need to be aware of first!
1. Tap water contains some toxins that are harmful to your health, Some of these toxins can be specifically damaging to the health of your hair, so i would recommend buying a water filter.
2. Avoid commercial soap and gels, again these almost always contain harmful toxins! These toxins can cause cancer along side many other ailments so it is important to avoid these! But natural products that do not contain these toxins. Personally i use Apivita this was recommend by Lydia if i am right.
3. Colder showers tend to be healthier for you, the water shouldn't be ice cold, neither should it be boiling hot.