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50 Freestyle: Should I Stay Underwater?

posted Apr 15, 2014, 1:07 PM by Pat Windschitl   [ updated Apr 15, 2014, 1:07 PM ]
Katie Arnold: It’s no secret that European women are some of the best 50 freestylers in the world. One of the things that we as a staff have noticed is that most of these women stay underwater for at least 10 meters off the start. Despite this observation, we still get push-back from athletes who feel their underwater dolphin kicks are not strong enough to be a weapon, and would rather pop up and start swimming as soon as possible.

I set out last month to find out if the data supports my belief that the underwater portion of the 50 freestyle is the fastest part of that swim. I looked at 10 of the top 12 women for 2011-2013, and used the three fastest races for which we had video for each. The chart below shows each swimmer’s average speed (meters per second) for various parts of the race:

  • Even the slowest underwater speed (2.460 mps) was faster than the fastest swimming speed (2.268 mps).
  • There is an obvious and dramatic drop in speed during the transition from underwater kicking to swimming on the surface.
  • The speed difference for these women underwater compared to above water ranged from .478-.767 mps faster underwater.

So what does it all mean? Simply stated, the underwater portion of the 50 freestyle is faster than the swimming portion. For the best in the world, they are about ½ meter per second (or more) faster underwater than they are on the surface. The important thing to keep in mind is not the actual speed of each part of the race, but rather the speed of each portion relative to the rest of the race. Regardless of an athlete’s perceived underwater ability, this is always the fastest portion of the 50 freestyle and should be a focal point to develop and improve.


A few weeks ago I discussed the women’s 50m freestyle and asserted that it is always in a swimmer’s best interest to exploit the underwater portion of this race. This week it’s the men’s turn. In setting out on my research, I wanted to see how similar the two races are. In addition to the obvious difference in speeds, there are a few other key differences that should be noted.

  • The slowest underwater speed (2.900 mps) and the fastest above water speed (2.310 mps) both belong to the same athlete, which means all these men are at least .590 mps faster underwater.
  • None of the men ever drop below 2.000 mps while all of the women dropped below this threshold during the above water portion of the race.
  • The largest speed difference from underwater to above for the women was .767 mps. All but two of the men had a speed difference larger than this, with four of these men going more than 1.000 mps faster underwater than above. 
Once again, what does it all mean? The men lose even more speed than the women when they transition from underwater kicking to above water swimming. Additionally, from 15m-35m and 35m-50m the group is fairly evenly bunched together, with all 10 swimmers within .100 mps of each other. Therefore, it is that much more important for male sprinters to work on the underwater and transition through the surface to exploit any advantage they can gain.