Take the world 100m sprint record for example, since 1912 there as been over a second knocked off the winning time, so at this rate in another 1000 years time the champion will run it in 0.0 seconds, that is impossible so at what point in time will the reigning champion and record holder hold onto his crown forever?
Methinks there will be an exponential decrease in winning times. I believe we have only reached this stage we are because of certain factors. For instance when they broke the 4 minute mile the athletes were plain amateurs, the track circuits was made up of cinders from the coking depot, no sponsorship and running gear you would expect from everyday joggers.
As Rov suggests, you can't compare any athletics or,say, swimming record unless conditions, equipment ie, shoes, swim-suit, rules etc are the same. But as this is impossible to regulate and control now, you just have to sit back and admire the performance, which largely depends on natural ability, dedication and training - not to mention sponsorship !
I think that If Jesse Owens were alive and in his prime today he would give old Bolty a run for his money !
Obviously it will never be 0.0 seconds lol, but the world record will kept being broken, athletes will always keep getting better, it will just not happen as quickly as it has done in history. There will be a point in the future where they will have to extend the world record time to 3 decimal places, for example, if no-one can beat 9.58 seconds and only equal it, then the official time will have to registered as 9.579 seconds. It'll probably take at least another 50 years for it to get under 9 seconds i reckon