Awhile back I had tried to record myself swimming freestlye and ask around the net for commentary, but it was with a low-quality camera and only above-water footage. Not getting too much feedback at that time, I decided to buy a underwater HD camera and try to use that as a reference and improve my freestyle technique. Over about 40 days I have recorded ~16 sessions, and tried to gradually improve things. Here is what I have improved:
- No longer crossing over arms in middle (at least most of the time)
- Entry occurs when arms are more stretched forward, before my elbow was bent ~90 degrees for some entries
- Left pull is a bit more consistent, but still not a clean S curve like right arm (yes I'm right-handed)
- kick is a bit tighter and more controlled (though this probably still needs to be made even smaller, with less knee kick)
- neck angle when breathing is less extreme, before I was turning upwards much more than necessary
I still look straight down at the bottom when swimming much of the time, partially because if I look forward with a 45-degree angle I can't really see much anyway because my goggles get in the way, although I know doing this will make my breathing more natural, and possibly improve my posture overall.
I have been doing alot of catch-up with a pull bouy and that seems to have helped me control my upper body more. Also been doing alot of stretches to enable my foot to stretch to a greater degree, and doing a few laps with zoomers to help improve my overall kick form.
Anyway, the result of my recent training can be seen in the following video, where I edited together a few sessions together, and you can see my technique from a few different angles, both above and underwater.
YouTube- Jeff's Freestyle Technique 7/5/2010
I was concerned about doing too much endurance training with 'bad' form,but I think I am nearly ready to start doing less form work and a little more endurance training. However before that I really would like to get some critique from some masters swimming forum members.
If I were to point out my #1 problem at present, it is a lack of 'balance' in the water, though I am not sure exactly what that means or how to work on it. When I see videos of pro swimmers like Michael Phelps I am amazed by how their arms seem 'anchored' in front, whereas I have to struggle to even keep them straight. It takes a conscious effort to not cross over the middle, and even then I can't seem to keep my arms 'anchored' in front.
I do most of my training in a housing-development pool with no swimming friends, so any commentary would be very helpful.
Thanks very much!
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Former Member
More really interesting stuff Budd! The testing with the pull buoy suggests an interesting experiment, if you have a swimmer push off in a streamline, and then push off and start kicking immediately you should be able to get a handle on how much propulsion the kick provides at different velocities. How much propulsion the kick provides has been a hot topic for many years and I think you have the tools to answer it. At least for a given swimmer's kick. Have you done any testing along these lines?
Assuming that the sort of descending sine wave in the sprinter graph is the result of dolphin kicking it would be interesting to see what the velocity curve looks like with just streamlining, and with flutter kicking, given the magnitude of the accelerations and decelerations one wonders whether with a flutter kick the two legs wouldn't largely cancel out. It is eye opening to see the magnitude of the drag during the leg recovery! Depending whether each dolphin kick spans one or two of those waves would tell us whether the upward portion of the kick is propulsive or not.
Would I be correct that your values for acceleration, power, and force are derived from the velocity data? If so, the force would be net force (propulsive - resistant drag) on the swimmer rather than propulsive force?
I also assume that the Aquanex measures pressure rather than force, i.e. it doesn't tell you what direction the force is in, and the pressure has to be multiplied by the surface area to determine the total force? If so, someone with a windmill style pull might be exerting force near the top of the stroke but much of that force would be downward and not be contributing to forward propulsion. Also, when dealing with pressure the total force is proportional to the surface area (actually projected backward facing surface area would be the effective area) so someone with a bigger arm (or better oriented arm) could exert a larger propulsive force than a smaller arm (or less well oriented arm) even though the pressure they are generating is smaller.
Almost by definition the faster swimmer is exerting more net productive force than the slower swimmer, i.e. the average force is greater even if the peak force is lower, and again the pressure at the hand is only half the equation, you have to multiply it by the effective surface area.
It may well be that the age group swimmer is experiencing more drag, but controlling a few more variables would more conclusively prove your hypothesis.
It seems to me that the velocity meter inherently measures net force so you need something more to tease apart propulsive and resisting drag forces. The pressure sensor helps in this regard but requires effective surface area to determine propulsive force. Video data taken from the front could help determine area, although an outline taken from the front angle and combined with out of the water measurements could do the trick at the expense of a lot of calculations, although I guess computers can take care of those.
Have you tried attaching the pressure sensor to the upper arm to see how much drag pressure there is there? That would give some very informative data with regard to your drag hypothesis.
More really interesting stuff Budd! The testing with the pull buoy suggests an interesting experiment, if you have a swimmer push off in a streamline, and then push off and start kicking immediately you should be able to get a handle on how much propulsion the kick provides at different velocities. How much propulsion the kick provides has been a hot topic for many years and I think you have the tools to answer it. At least for a given swimmer's kick. Have you done any testing along these lines?
Assuming that the sort of descending sine wave in the sprinter graph is the result of dolphin kicking it would be interesting to see what the velocity curve looks like with just streamlining, and with flutter kicking, given the magnitude of the accelerations and decelerations one wonders whether with a flutter kick the two legs wouldn't largely cancel out. It is eye opening to see the magnitude of the drag during the leg recovery! Depending whether each dolphin kick spans one or two of those waves would tell us whether the upward portion of the kick is propulsive or not.
Would I be correct that your values for acceleration, power, and force are derived from the velocity data? If so, the force would be net force (propulsive - resistant drag) on the swimmer rather than propulsive force?
I also assume that the Aquanex measures pressure rather than force, i.e. it doesn't tell you what direction the force is in, and the pressure has to be multiplied by the surface area to determine the total force? If so, someone with a windmill style pull might be exerting force near the top of the stroke but much of that force would be downward and not be contributing to forward propulsion. Also, when dealing with pressure the total force is proportional to the surface area (actually projected backward facing surface area would be the effective area) so someone with a bigger arm (or better oriented arm) could exert a larger propulsive force than a smaller arm (or less well oriented arm) even though the pressure they are generating is smaller.
Almost by definition the faster swimmer is exerting more net productive force than the slower swimmer, i.e. the average force is greater even if the peak force is lower, and again the pressure at the hand is only half the equation, you have to multiply it by the effective surface area.
It may well be that the age group swimmer is experiencing more drag, but controlling a few more variables would more conclusively prove your hypothesis.
It seems to me that the velocity meter inherently measures net force so you need something more to tease apart propulsive and resisting drag forces. The pressure sensor helps in this regard but requires effective surface area to determine propulsive force. Video data taken from the front could help determine area, although an outline taken from the front angle and combined with out of the water measurements could do the trick at the expense of a lot of calculations, although I guess computers can take care of those.
Have you tried attaching the pressure sensor to the upper arm to see how much drag pressure there is there? That would give some very informative data with regard to your drag hypothesis.
