When you have to rely on a one-in-a-billion genetic freak to make new records, we are 'close to the limits'. When you have to have teams of scientists and coach

When you have to rely on a one-in-a-billion genetic freak to make new records, we are 'close to the limits'. When you have to have teams of scientists and coaches working to improve one individual just a tiny bit, we are 'close to the limits'. It's not like you can pop a pill and run 100m in 5s, blowing away current records.