I am really getting into Karting at the minute as I have found how much cheaper it is than track days. I used to spend around £500 per day on track days when you take fuel costs and tire wear in to account. Karting is costing me £100 max and I get to race competitively instead of just driving around a circuit waiting for slower cars to pull over. I have also started using Bodybuilding Supplements to help me stay focussed through out the day as it can get quite mentally tiring. To have an energy and recovery drink after each session really helps me keep mentally focused as well as physically.