Question: Do I Have to Buy Special Insoles for My Hiking Boots?
No, you don't have to
If, like me, you prefer lightweight hiking shoes, adding thick insoles can actually be a hindrance. The heavier and stiffer your boots, though, the more likely you are to want those insoles.
There are other reasons for buying special insoles. Even though hiking boot and shoe manufacturers try to create stock insoles that offer the right blend of support and padding, they just can't suit every single type of foot out there.
If you know you need extra support for high arches or flat feet, extra cushioning, or just something a little extra to fill the space in a high-volume boot or shoe, it's time to shop for insoles. Also, a new pair of insoles can sometimes help you eke a few more miles out of boots that are nearing the end of their useful life.
Many hiking boots and shoes have removable insoles -- just pull them out and slip the replacements into place. If your boots have permanent insoles that are glued in, you can sometimes pry them out without causing too much harm. And if you're compensating for low-volume feet, you might not want to remove the original insoles at all; just slide the new insoles in on top of them.
When not to buy insoles
That said, don't fall into the trap of buying insoles to compensate for poorly-fitted footwear. Put in the time trying on boots to find the best fit before you buy. And if you already know you'll need insoles to compensate for so-called "problem feet" no matter what, try to bring them with you -- or buy them -- while you shop for your new hiking boots.
Also, a quick note on stability. If your feet tend to overpronate (roll in too much when you walk) you can purchase purpose-built walking/running shoes and supportive insoles to correct this. However, most sturdy hiking shoes and boots are naturally wider and more stable than your average walking or running shoe. So while you certainly can fit corrective insoles in most hiking shoes, you might not always need them. (Flexible, minimalist hiking shoes are the biggest exception to this rule.)