The best way to visualize this process is with poker chips. Imagine there is a cash register. When you put dollars into the register, the cashier gives you chips (tokens). When you return the tokens, the cashier gives you dollars back. When you give Strata Protocol $BLOCK, it gives you Athlete tokens. When you sell them back to the protocol, it gives you $BLOCK. The more of the athlete token in circulation, the more $BLOCK it costs to purchase a token and the more $BLOCK you receive by selling tokens.