10% Higher Rowing Power

[Nomath]

I really question whether the "pogo stick" effect plays much of a role in rowing as the movements are too smooth, small, and slow compared to say, someone jumping.

I think you are, as often, misinformed. I measured the acceleration at the catch using a DIY sensor. I am just an average and senior rower (72 yrs). My acceleration at a 2:00 pace per 500m amounted to 7.5 m/s². I am sure that elite rowers surpass 9.8 m/s² by far. As I have said multiple times on this forum: the take-off at the catch is very similar to a countermovement jump.

The graph below is from 50 consecutive strokes. The one exception is the first stroke, that starts with standstill flywheel. I had problems to sync all drives at time=0, but you can see the point.

[faach1]

I really question whether the "pogo stick" effect plays much of a role in rowing as the movements are too smooth, small, and slow compared to say, someone jumping.

I think you are, as often, misinformed.

Agreed Mathieu.

[frankencrank]

I really question whether the "pogo stick" effect plays much of a role in rowing as the movements are too smooth, small, and slow compared to say, someone jumping.

I think you are, as often, misinformed. I measured the acceleration at the catch using a DIY sensor. I am just an average and senior rower (72 yrs). My acceleration at a 2:00 pace per 500m amounted to 7.5 m/s². I am sure that elite rowers surpass 9.8 m/s² by far. As I have said multiple times on this forum: the take-off at the catch is very similar to a countermovement jump.

The graph below is from 50 consecutive strokes. The one exception is the first stroke, that starts with standstill flywheel. I had problems to sync all drives at time=0, but you can see the point.

The "pogo stick" effect has nothing to do with the acceleration after the start of muscle contraction but, rather, the adding of energy into the ligaments and tendons that can be used in increase the force when the muscles do contract. It is the hop before the jump, not the jump itself. In rowing, there isn't much of a hop before the jump. There is a little one (slowing before the catch) but nothing like seen in athletics (even if it were there it is simply there and nothing that is going to be altered much). That is why I would be surprised if it accounted for much. I have been surprised before though in other ruminations. Might I say that analyzing those prior surprises taught me a lot and has, in part, led me to my "three" technique improvements for power increase for which you can find a discussion on another thread.

[frankencrank]

Let me ask you a question regarding your stroke. I see you get a nice boost at the catch but then it is flat. That suggests that your force drops after the catch then, later, increases. That force pattern doesn't make much sense to me. Can you help me understand what is going on? It also appears you are at a very low stroke rate as speed almost drops to zero between strokes. can you elucidate more?

[Nomath]

In rowing, there isn't much of a hop before the jump. There is a little one (slowing before the catch) but nothing like seen in athletics (even if it were there it is simply there and nothing that is going to be altered much). That is why I would be surprised if it accounted for much.

May I suggest that you try harder to get informed first. Your statements lack quantification. There is a lot of quantitative information around about the countermovement jump, which is well-researched movement. As for the slowing down before the catch, you can find quantitative information in my topic on the DIY sensor.

[frankencrank]

In rowing, there isn't much of a hop before the jump. There is a little one (slowing before the catch) but nothing like seen in athletics (even if it were there it is simply there and nothing that is going to be altered much). That is why I would be surprised if it accounted for much.

May I suggest that you try harder to get informed first. Your statements lack quantification. There is a lot of quantitative information around about the countermovement jump, which is well-researched movement. As for the slowing down before the catch, you can find quantitative information in my topic on the DIY sensor.

Informed about what? I am reasonably informed about both physiology (physician) and physics (engineering undergraduate) basics. I found this resource https://iopscience.iop.org/article/10.1 ... ab4226/pdf and these people explicitly state they ignore one of the areas I am concerned about and that considering it results in about a 10% difference (I suspect it is greater in the real world for a reason they have not considered) although it probably isn't possible to eek out that much gain - but any gain is useful, correct?

As I said, I would be surprised if the countermovement jump was a significant contributor. But, it doesn't matter, as it is what it is. There are many other areas in which potential improvement could be explored.

[Nomath]

Let me ask you a question regarding your stroke. I see you get a nice boost at the catch but then it is flat.

This exactly demonstrates your lack of interest in details that matter. It makes your statement "I am reasonably informed about both physiology and physics basics" a joke.

It is explained in the introduction of the topic on the DIY sensor.
A drive on a C2 erg starts from handle speed = 0. A rower first has to catch up with the speed of the flywheel ; it has an equivalent speed of about 1.5 m/s. Since you keep your arms fully stretched after the catch, this can only be done by accelerating the mass of your body, by pushing hard on the foot stretchers. This acceleration to 1.5 m/s at, say, 9.8 m/s² and an upper body mass of 60 kg takes about 450W during 0.15 sec. Once you reach the speed of 1.5 m/s, power can be transferred to the flywheel. But the power to accelerate the flywheel is d(½I*ω²)/dt. The flattening of the curve reflects that. It is not a weakness in force or in style! It is physics !!!

I will not further comment on your posts before they reflect that you have read and understood my topic on Fan Blade Physics. That is about the relevant physics for indoor rowing, not your musings about potential improvements.

[frankencrank]

Let me ask you a question regarding your stroke. I see you get a nice boost at the catch but then it is flat.

This exactly demonstrates your lack of interest in details that matter. It makes your statement "I am reasonably informed about both physiology and physics basics" a joke.

It is explained in the introduction of the topic on the DIY sensor.
A drive on a C2 erg starts from handle speed = 0. A rower first has to catch up with the speed of the flywheel ; it has an equivalent speed of about 1.5 m/s. Since you keep your arms fully stretched after the catch, this can only be done by accelerating the mass of your body, by pushing hard on the foot stretchers. This acceleration to 1.5 m/s at, say, 9.8 m/s² and an upper body mass of 60 kg takes about 450W during 0.15 sec. Once you reach the speed of 1.5 m/s, power can be transferred to the flywheel. But the power to accelerate the flywheel is d(½I*ω²)/dt. The flattening of the curve reflects that. It is not a weakness in force or in style! It is physics !!!

I will not further comment on your posts before they reflect that you have read and understood my topic on Fan Blade Physics. That is about the relevant physics for indoor rowing, not your musings about potential improvements.

Ugh, flattening of the curve makes sense. a flat curve (your curve, constant speed) does not unless your force is just balancing the drag force trying to slow down the wheel. Physics!