Balancing Force and Speed

[SlickC2]

I've yet to master the correct technique after nearly a couple of years - sigh - and I've been thinking lately about the forces applied. I've concluded that technique is not just about the correct sequence of actions but also how the forces are applied. For example, just think simply about the biomechanics: At the catch position (see diagrams at: http://www.clubpiscine.ca/159-tips-and- ... iques.html), the feet do the pushing but I don't think it's just a simple push "backwards". For a start, the footrest is angled so if a force normal to the footrest is applied (if it's not normal your feet would tend to slip - one of the reasons you should practice without straps), the foot force has not only a component opposite to the force pulling the chain but a component tending to lift your backside off the seat (to counteract the torque applied by the chain force). So viewed in that way the foot force is actually not aligned with the chain but one pushing you up off the seat - and backwards as well. In other words, at the catch position you should push so as to try to lift your backside off its seat and not just simply push yourself backwards. Another reason for doing so is that with the legs crunched up in the catch position, you can't push backwards with maximum force, which probably occurs during the drive.

The pudding-proof of this is the force curve illustrated quite nicely by Peter Dreissigacker in his video (https://www.youtube.com/watch?feature=p ... iQ0Mqlk_Lo). With a high damper setting it is hard, particularly for novices and light weight rowers, to get the force curve to rise sharply at the beginning. You would literally have to be "jumping off the seat" to do so. Whereas, the arms, being outstretched, can kick in at any time and so are best left to finish off the stroke and force curve, once the legs and back have done their bit. So with a reduced foot force at the catch, but with speed added in, you can get the force curve to rise (as power is force times velocity). In other words, you can compensate for the reduced force with speed. Well, that's the explanation I have come to, and the conclusions with regard to my training are:

1. To build up muscles, train at the higher damper settings but accept that your times will be slower than the best possible - because you will be lacking speed.

2. To build up speed, train as per suggestions by Peter Dreissigacker at the lower damper settings.

3. Your best times will fit in somewhere between these two extremes as you'll need to combine strength and speed. Lighter (and less muscular) rowers like myself will probably tend to use lower damper settings than those with more muscle.

I hope this all makes sense.

Cheers

[jamesg]

legs crunched up in the catch position

If we avoid that, most technical problems disappear.

The erg has a flywheel, so drag does not determine handle force, we do; Newton. According to him, on the grounded erg we have to accelerate our entire body mass before the chain can engage, so it seems reasonable to start with the only part of us that can do that, the legs. Then, in sequence, trunk and arms.

If in doubt, the monitor shows both Watts and Rating, so we can try all possible techniques and see what happens.

[Cyclingman1]

I've concluded that technique is not just about the correct sequence of actions but also how the forces are applied. For example, just think simply about the biomechanics:

It is very easy to get bogged down in the physics of a rower. Not sure how productive that is. One can experiment a good bit to find the most powerful rowing technique. Different body types and proportions may require different foot rest positions or drag factors. Perhaps lifting off the seat some is not bad for some. It is whatever produces the best pace over some distance.

[Hillclimber]

1. To build up muscles, train at the higher damper settings but accept that your times will be slower than the best possible - because you will be lacking speed.

2. To build up speed, train as per suggestions by Peter Dreissigacker at the lower damper settings.

Cheers

Another strategy, which is the polar opposite of yours, is to:
a. build strength (and fitness!) by lowering your typical 2k DF by about 10, drop your rate to 18-20, at pace 2k plus 10', and work for 20-30 min. that will give you strenght.

b. build speed (and fitness!) by increasing DF by 10, raise the rate to 38-40, and hammer out 500m sprints at pace 2k minus 3'.

i'm sure the experts will chime in: hopefully i'm not adrift here in my understanding of the fundamentals.

damien

[Coninxd]

The way I see it is that low or high drag factor or damping setting, you can't really compare just based on physiscs. In the end the software does some calculation to make it comparable. Probably C2 did a good job at leveling the field, but I bet there still is some optimal setting to get the best time givven the same input power.

[hjs]

Drag is often overrated. High drag will not build strenght perse, It will mostly give you a sloppy technique. Low drag will not direct build speed, but it will teach a sharp stroke.

A strong stroke is mostly build via low strokerates. Strenght for sprints is best build via basic barbellwork. Squats/deadlifts/rows.

[Balkan boy]

I've always thought of rowing on high drag/damper is like rowing upstream on fast water.

[hjs]

I've always thought of rowing on high drag/damper is like rowing upstream on fast water.

High drag could be seen as rowing a slow heavy boat, the oars go slow through the water.

[JLB123]

Couple of points on this.

1)

Just to clarify: The C2 does not directly measure force. It measures the speed of the flywheel, which it uses to infer force applied. This is fine 99% of the time, but what you're trying to do is analyse the exact point of the catch, which it won't work for, as not all forces are captured by the flywheel (see 2). Also, just to clarify, the force curve is very different to the power curve and the acceleration curve - you need to be careful about trying to infer one from the other

http://www.biorow.com/RBN_en_2012_files ... News11.pdf

2)

So with a reduced foot force at the catch, but with speed added in, you can get the force curve to rise (as power is force times velocity)

Not convinced I follow your logic; let's ignore the Power = force * velocity as it's misleading in the context of a flywheel - the formula assumes force and velocity are independent of one another, which they're not (as increasing speed of flywheel increases resistance i.e. force). The far more relevant equation is force = mass * acceleration. Now, at the catch, rower has to reverse their own bodyweight before ANY force can be applied to the flywheel. Trying to move faster means reversing their weight faster, which requires more force. BUT on a dynamic you would have a point, as the rower does not need to reverse their bodyweight, and the flywheel will be moving faster if drag is lower, so the acceleration required to achieve a high speed is lessened (although note this wouldn't make the force curve rise)

3)

I think (although I don't think there's any scientific research on the matter) that force, not power is what stimulates muscle growth (that's why weightlifters lift heavy weights slowly rather than light weights quickly). So in that sense, high drag, slow strokes would arguably be more effective (with the associated health warnings). For developing speed, fast twitch muscle is necessary, which is definitely about high speed work.

So not sure I agree with your logic (or why your logic leads to your conclusions), but agree with the conclusions