I recently posted these 10 myths on some triathlon websites and stirred up some good conversation. So here I go again.....
Myth #1 To go faster in swimming one must push out the back of the arm pull.
I believe this myth may have originated with an article that appeared some time in the 90's. The article showed a swimming figure mimicking Alex Popov's freestyle pull. It showed the figure with the left arm in front and the the right arm in back ready to exit the water for the recovery. A graph showed the velocity of Popov's body in the water as a function of the position of the hand. The velocity ranged from nearly 3 meters per second down to about 1.4 meters per second during a single pull cycle. The slowest speed occurred when the hand appeared to be at around the shoulder and the fastest speed occurred in the position shown in the figure. The author erroneously concluded that since the speed was so high as the right hand was about to exit, that this is where the most power must be....hence push out the back.
My study with the velocity meter doing freestyle concurs that it is these two positions that consistently show the highest and lowest velocities of the stroke cycle in freestyle (though I was seeing more like a 30 to 40% drop, not 50%). But it is not because of the power out the back that we see the speed highest in this position. It is because it is by far the position of least drag (most streamlined). The propulsive power in this position actually is derived mostly from the left arm out in front and the kick, with little or no power coming from the end of the arm pull. The propulsive power may be even greater when we see the hand at the shoulder (slowest body speed), but because the arm is jetting straight out, perpendicular to the body, the drag coefficient skyrockets and our speed drops instantly.
The harm that is done by pushing out the back is that it delays the recovery and slows the stroke rate. Most of the arm propulsive power is derived from the entry to the shoulder (called the front quadrant....about 1/2 of the total arm cycle time is spent there). So the sooner one can get the hand back to the front quadrant after leaving the shoulder, the better.
If you happened to be blessed with Mercury motors for legs, like Michael Phelps, Ian Thorpe, Gary Jr, Natalie Coughlin etc, then you can afford to use a slower stroke rate...but hold in front, not in back.
For the rest of us mortals, keep your arms moving faster and in the front quadrant. Think you can't do that for a 1500? Think again. Lot's of distance swimmers use high arm stroke rates. You just have to train that way and get fit.
Regards,
Gary Sr.
The Race Club
Parents
Former Member
I'm a little bit confused here because it seems to me that forces (propulsive and resisting drag) correlate with acceleration rather than speed.
If minimum speed occurs when the arm is about even with the shoulder that implies that you are slowing down leading into this point, i.e. propulsion forces are less than resistance in the preceding phase, and that you are speeding up in the following phase, i.e. propulsion is greater than resistance.
I haven't seen an actual graph to see where the periods of acceleration and deceleration start and end but it seems to me that the conclusion should be the opposite of what was given here. The front quadrant is not more propulsive but is used to position the body for the period of peak propulsion in the rear quadrant, and that if peak velocity occurs as the hand exits then the propulsive phase extends all the way to the hand exit.
Is there a graph of the velocity pattern in freestyle available on the web?
Have I misunderstood the original argument or gone astray in my reasoning?
P.S. Happy Canada Day! :canada:
Astray...i'm afraid. If one watches a good swimmer using the velocity meter from side view, isolating the arms (legs tied with a band so as not to confuse the information), one sees a repeatable pattern of fastest speed with one arm outstretched (creating lift) and the other arm about to leave the water. The slowest velocity occurs repeatedly when the hand is about at the shoulder level underwater and the upper arm is at near right angles. The changes in velocity ranges from a drop of 30% all the way up to 50% that occurs in a matter of a few tenths of a second....over and over again. These positions of maximum and minimum velocity should not be confused with positions of maximum and minimum propulsive power, simply because the drag created by the changing position of the arm is so vastly different, these forces are more significant than the power at each position.
At the end of the arm stroke, the hand is actually moving forward again (as it was in the beginning), so there is not only no power here, but a small amount of frontal drag.
When considering where the power is it is best to consider the physiology of the two regions, when pulling. There is simply much more musculature and mechanical strength in the front quadrant.
Gary
I'm a little bit confused here because it seems to me that forces (propulsive and resisting drag) correlate with acceleration rather than speed.
If minimum speed occurs when the arm is about even with the shoulder that implies that you are slowing down leading into this point, i.e. propulsion forces are less than resistance in the preceding phase, and that you are speeding up in the following phase, i.e. propulsion is greater than resistance.
I haven't seen an actual graph to see where the periods of acceleration and deceleration start and end but it seems to me that the conclusion should be the opposite of what was given here. The front quadrant is not more propulsive but is used to position the body for the period of peak propulsion in the rear quadrant, and that if peak velocity occurs as the hand exits then the propulsive phase extends all the way to the hand exit.
Is there a graph of the velocity pattern in freestyle available on the web?
Have I misunderstood the original argument or gone astray in my reasoning?
P.S. Happy Canada Day! :canada:
Astray...i'm afraid. If one watches a good swimmer using the velocity meter from side view, isolating the arms (legs tied with a band so as not to confuse the information), one sees a repeatable pattern of fastest speed with one arm outstretched (creating lift) and the other arm about to leave the water. The slowest velocity occurs repeatedly when the hand is about at the shoulder level underwater and the upper arm is at near right angles. The changes in velocity ranges from a drop of 30% all the way up to 50% that occurs in a matter of a few tenths of a second....over and over again. These positions of maximum and minimum velocity should not be confused with positions of maximum and minimum propulsive power, simply because the drag created by the changing position of the arm is so vastly different, these forces are more significant than the power at each position.
At the end of the arm stroke, the hand is actually moving forward again (as it was in the beginning), so there is not only no power here, but a small amount of frontal drag.
When considering where the power is it is best to consider the physiology of the two regions, when pulling. There is simply much more musculature and mechanical strength in the front quadrant.
Gary
