A while back, I jumped on the triathlon website Slowtwitch and got attacked for saying that the power in the freestyle pull comes in the front of the stroke (hand entry to shoulder), not in the middle (shoulder to belly button) or back (belly button to release). Nonsense...they said. Didn't you read the article by Popov's coach showing the power is at the end of the stroke?
That never made sense to me. After all, at the end of the stroke there is only about one muscle still working, the tricep, and the hand is not in that position for very long.
At last, I got the proof I needed. A few weeks ago I was tested on the Velocity Meter, a very cool device that measures the speed of the body through the entire stroke cycle. It was VERY revealing and provided tons of information I could not get elsewhere.
Such as:1) the body speed slows by as much as 40% from the fastest to the slowest point during a single arm stroke. 40%!!! That is huge. The difference in speed is directly caused by the body going from a relative streamlined position to a very non-streamlined position and back again.
2) The fastest point in the stroke cycle is when the hand first enters the water and the slowest point is when the hand is about at the shoulder underwater. That is when the upper arm is pointing nearly perpendicular to the line of the body (ie most drag).
I realize that the speed of the body at any given instant is a result of the propulsive power minus the drag forces, that one cannot determine just from the velocity that the power is really greater in front. But when the speed drops from 2.5 meters per second when the hand is in front to 1.4 meters per second when it is in the middle, I have to believe that the power in front is greatest.
By the way, the propulsive power of the arm is created by both lift forces at the beginning and drag forces in the middle, as the hand shifts from forward motion to backward motion (then forward again as it releases).
Anyway, read my latest blog on our website www.theraceclub.com to find out more revealing secrets from the Velocity Meter.
Gary Sr.
The goal should always be to develop that magic touch of the hand exiting ahead of where it entered the water.
In my opinion the "magic" here is kicking hard. I don't care how efficient your pull is, there's no way your hands exits ahead of where it entered unless your kick is propelling you forward.
If your arm is moving backwards, then you're not moving forward. Instead, you're moving water backwards instead of propelling the body forward. The goal should always be to develop that magic touch of the hand exiting ahead of where it entered the water.
An educated working-class, novice perspective here:
The greatest power occurs at the point in stroke where swimmer achieves peak speed given drag forces are constant (whatever stroke position that may be). This might vary from swimmer to swimmer.
One thing I haven't noticed being mentioned by you elite swimmers is the the factor of swimmer density. The mass/volume ratio will play a significant part in overcomming drag force deceleration after the start.
Even though I haven't even tried a start on the block yet, the way I look at it, the taller, skinnier, relatively muscular (for density) swimmer will have a given advantage. I'm wondering if it's not really the velocity of start opon entering the water, but how far out you are when you enter.
Mswimming and Chris: thanks for correcting my math:agree:. It never was my strong point. The comparison to Lezak means that I can match his strokes per length and distance per stroke but that is not nearly as important speedwise compared to turnover rate and maintaining dps over distance. :doh: --mjm
If your arm is moving backwards, then you're not moving forward. Instead, you're moving water backwards instead of propelling the body forward.
Here's another perspective...
I don't view hand and arm in the stroke cycle as "paddling" in that you move water backwards. Rather it's kind of like doing a one armed pull-up on an underwater ladder. As each hand grabs onto a rung, you pull yourself past the point where you latched on. It's just a slightly different take on what's going on under the surface.
And as Kirk said, you would need some additional momentum for the hand to exit past the point of entry, but it does happen with very good swimmers.
Getting back to what Gary Hall Sr. described about the power position, I guess it's more about swimming long and stealthy by keeping the arms out front and extended...in the front quadrant.
The reason for that "horrible arm-out position" is because you're flying. At that position, you've already propelled part of the body beyond where the hand entered the water. Yes indeed, I vote for the power up-front position, for that is where all the action is taking place. It is where the hand applies force to the water and the water responds back with equal force and propels us ahead.
OK....I have kept everyone in suspense long enough. The answer to the poll question is that an excellent swimmer (my son Richard 1:37 200 free in college) who does a very clean sling shot racing dive, hit the water at 14.8 MPH and at one second from that time (he is now completely submerged, streamlined and even starting a kick) he has slowed to 3.5 MPH, quite a bit slower than his race speed. That is a 76% reduction in speed that occurs in exactly one second with an excellent dive.
Congratulations to those of you who got it right.
The moral to the story is unless you have legs like Phelps, Lochte, Leveaux, Coughlin or Hyman, you'd better get your rear end up to the surface and start swimming. Otherwise you are just losing ground.
Gary Sr.
The beginning of every competitive stroke only starts the production of power or inertia. Drag forces in conjunction with lift forces (the hand moving into stable water) are the most potent producers of power and occur later in the stroke. The first quadrant of any stroke merely sets the wheels in motion (setting-up the stroke), so peak drag and lift forces can take place during the transition from the first quadrant and into the second quadrant of each competitive stroke. The hand entry and beginning of the stroke does not produce any significant power but is critical in establishing peak efficiency as the hand and forearm become vertical. The power that is produced during the end of the first quadrant and through the start of the second quadrant is where peak power (torque) is produced. The end of the second quadrant of the stroke where the arm extends (and away from the body) can help maintain the power gained through the power phase. There is a lot of research done at the Olympic Training Camp Biomechanics’ Facility showing that peak power is produced during the transition from the 1st and into the second quadrant (another spike comes at the end of the stroke when the hand tends to accelerate (this maybe one reason it seems power is generated at the beginning of the stroke).
It's nice to partition the stroke, but only if the body remains still. However, the body moves forward and the hand remains fixed in location and ideally exits ahead of where it entered.:angel:
In my opinion the "magic" here is kicking hard. I don't care how efficient your pull is, there's no way your hands exits ahead of where it entered unless your kick is propelling you forward.
don't forget that after the hand enters there is arm extension, maybe some glide, then a drop to the catch position. during all this time you(and your hand) are still moving forward even if you are using a pull bouy. by the time you start to pull it is not hard to imagine that the hand is well ahead of where it entered the water. if the distance from hand entry to hip is roughly 4ft and you can pull 25yds in 15 strokes then each arm stroke is moving you about 4ft assuming a 5yd pushoff. of course sadly for me, a good kick also helps.
