if you are serious about training, you should really invest in a good pair of weightlifting shoes. here's why: when doing a squat you are exerting a force downwards which transfers to the surface your feet are on, then upwards to move your body and the weight. if you are wearing a running shoe, or shox for example, some of that force that you are exerting downwards gets absprbed by the shoes, then the leftover is transfered to movement. so say you are exerting 100N of force downwards, and 20N is absorbed by the shoe, now 80N is transfered to the wieght and your body...you are not being as efficient as you could be. the difference between weightlifting shoes and normal shoes is that the sole is made of solid rubber or wood, which compresses very little...thus none of the force you are exerting downwards is being absorbed and it is all transferred to the weight. this might not sound like a big deal but trust me, you are missing out on something that will drastically increase your performance! i have the adidas ironwork II. these shoes will also help if you find it difficult to squat deep. they have a slight heel, which allows you do go very deep. the ironworkII has the slightest (smallest) heel i believe, there are some others out there that are very high that i would never use because i am able to squat very deep without lifting shoes. this is a VERY good investment!