Running in Socks
Track shoes made for training, or as we like to call them, sneakers, have cushion that gets pounded down and loses it strength and stability. You need your training track shoes to hold their structure in order to support your feet and thus your legs and back because you spend all most all of your running time in these types of track shoes.
If you train on overused shoes, you are repeatedly hammering the sections of your feet, legs, and back that need the most support. You know this because the way you run wears the shoes down in these places faster than others.
Am I Missing Something?
You wouldn't go ice skating without skates nor swimming without a suit, would you? Then why would you run without the correct track and field equipment? Yes, track and field is a sport with relatively little equipment needed, you can wear basically anything to train in, but you must take care of your feet!
Track spikes are made special for each individual event. They do not just help you run fast, they put your feet and therefore the rest of your body in the correct position to maximize your ability and not get injured. Buy track spikes.