Since the early 1900s, when sports organizations began to methodically keep records of absolute performance, such as times for the 100 yd. dash, experts have speculated on what the ultimate limits of performance are. In the 1930s and 1940s, four minutes was regarded as the ultimate limit for the mile run. Many of these “limits” were based on analysis of the physical capacity of humans. In 1954, Roger Bannister broke the 4 minute barrier with 3:59.4. As of March 2014, the record for the mile has fallen to 3:43.13 (1999).
In swimming, the first “magic” number was 1 minute for the 100m. freestyle, which Johnny Weismuller broke (58.6 s. in 1922). Now, the record is 46.91 s. This record was set during the “polyurethane” suit era, suits which were banned in 2010. The progression of records is nicely documented in this Wikipedia link: World record progression 100 metres freestyle.
This brings us to the question: What is the limit for the 100 m. freestyle? Below is a 5 part video series featuring 2 time Olympic champion Alex Popov. It covers his training and stroke technique in detail and addresses “theoretical limits” for swimming speed.
Opinion (IMHO): I believe that the best chance of a breakthrough in freestyle performance will be accomplished with a radical change in kicking technique and timing. As you watch these videos, note that how Popov uses the dolphin kick in some drills.
“Popov – What is the Limit?” Part 2:
Here are links to view the other 4 parts:
Alexander Popov, What is the Limit? Part 1 | Part 3 | Part 4 | Part 5
Sun Yang
For another view of a champion that illustrates how the kick has evolved in freestyle, see this excellent underwater study of Sun Yang in the 1500 m. freestyle, 2012 Olympics (no funny plastic suits allowed!!). Note that he averages < 60 s. for each 100 meters, while using about 28 strokes per 50 meters. By 1950s standards for technique, he is breaking a lot of “rules” regarding body roll & alignment, kicking, head position, and more! Now, with the scientific studies of swimming, we know that those rules were not based on physics, and thus they were replaced by better techniques.