Motorcycle Racing
Motorcycles are extremely dangerous as is, and that's without even factoring in the racing part. The bikes don't really offer you any protection from the outside world or the other racers. There are no seatbelts and no airbags. It's just you, the bike, and the road.
It's Just As Dangerous As You Would Imagine
Motorcycle racers take their lives into their own hands when they hop on the track. For example, just one singular motorcycle racing event (The Isle of Man TT) has claimed over 200 lives in the past 30 years. If that dissuades you from becoming a motorcycle racer, you're welcome.