Most professionals would say that because of the lack of arch support, sandals are bad for you. But looking at history, I'd say the opposite would be true. During Pax Romana, gladiators fought each other in the coliseum, fighting not with Nike and Adidas shoes, but with sandals. These sandals that the gladiators wore did not give them arch support and did what they were suppose to do: Protect the feet of the gladiators whenever they took steps. Back in those days, people didn't wear brand shoes, but instead wore sandals to travel from one place to another. In fact, there were only so many people that were able to go from one place to another on a horse/donkey/camel. Those people had to walk. Society now relies on cars to get from one place to another, and we wear shoes that supports our arches so it'll 'help us'. I believe that by relying on those things, we weaken our bodies, and prevent ourselves from growing to our full potential.
There are lots of things we do that put ourselves at a disadvantage, but the thing about putting ourselves in that disadvantage is that because of that, we grow stronger. Only through hard times can an individual grow stronger. Only through some pain can we grow callouses that will protect us from further pain. Yesterday, for about 5 hours, I was walking around in flip flops, and one of the kids that were with me told me that by the end of the day, I would be complaining about having pain in my foot. I replied and told him that I wouldn't feel the pain because I walk properly and my feet are in shape. It's funny that because ever since I was young, I've been wearing flip-flops, and without realizing it, I've been strengthening my feet, allowing myself to 'start off' stronger.
Some schools start their sports with conditioning week, but how much more prepared would the athletes be if they've been conditioned before that and hadn't stopped growing?
Conditioning your body means to put yourself at a disadvantage. That disadvantage eventually becomes an advantage, which helps you pursue your goal.