You can maximize the benefits of wearing armor while reducing or eliminating some of its drawbacks.

Armor Mastery: The maximum Dexterity bonus of your armor improves by +1. You must be proficient with the armor you are wearing to gain this benefit.
Prerequisite: Armored Defense.

Armored Defense: When calculating your Reflex Defense, you may add either your heroic level or your armor bonus. whichever is higher. You must be proficient with the armor you are nearing to gain this benefit.

Improved Armored Defense: When calculating your Reflex Defense, you may add your heroic level plus one-half your armor bonus (rounded down) or your armor bonus, whichever is higher. You must be proficient with the armor you are wearing to gain this benefit.
Prerequisite: Armored Defense.

Juggernaut: Your armor does not reduce your speed or the distance you can move while running. You must be proficient with the armor you are wearing to gain this benefit.
Prerequisite: Armored Defense.

Second Skin: When wearing armor with which you are proficient, your armor bonus to your Reflex Defense and equipment bonus to your Fortitude Defense increase by +1.
Prerequisite: Armored Defense.