Drive length, leg length, height, & performance

[nick rockliff]

Did a 10k r20 this evening just under 40min and 800 strokes.

I looked at a few things that I'd never bothered with before.

Ergdata doesn't seem to record these unless I'm missing something?

Drive time avg 0.66
Avg force 540
Drive length mainly 1.33

Meaningless to me, the most important thing is being able to still do a sub 40 10k r20 as I get close to 70

[JaapvanE]

Ergdata doesn't seem to record these unless I'm missing something?

It doesn't. Never understood why, especially as competing machines do record this.

[Sakly]

Ergdata doesn't seem to record these unless I'm missing something?

It doesn't. Never understood why, especially as competing machines do record this.

And ergdata could store this on the phone, not even pushing it to the logbook, if it doesn't fit to the data structure.

[ahooton]

Did a 10k r20 this evening just under 40min and 800 strokes.

I looked at a few things that I'd never bothered with before.

Ergdata doesn't seem to record these unless I'm missing something?

Drive time avg 0.66
Avg force 540
Drive length mainly 1.33

Meaningless to me, the most important thing is being able to still do a sub 40 10k r20 as I get close to 70

Incredible. I truly hope I will be achieving this when I get to your age. Wonderful to see.

[jcross485]

I don't think I've ever looked at drive length before let alone used it as a focus in training. Any time I have consciously tried to increase stroke length, it has resulted in overcompression at the catch or an exaggerated lean back; the overcompression at the catch puts me in a less than optimal position to deliver power to the foot plates and handle and the exaggerated lean back ends up lowering stroke rate a touch without any real improvement in power. My own n=1 is that I am more focused on optimally delivering power each stroke within what feels to be the most powerful positions and length.

I am 5'10" tall with disproportionately long legs and arms for my height with a disproportionately short torso. I do not have the height / length of most heavyweight rowers and would probably be more in line with lightweight rowers from that standpoint while being a bit heavier. I can't really change my height / length or proportions so I simply focus on working within the cards I've been dealt. I think focusing on developing power per stroke and getting comfortable with higher stroke rates will pay off in the long run much more than trying to develop a longer stroke, if that makes sense.

[Cyclingman1]

Too many bad things can yield improvements in drive length, so drive length is a risky thing to optimize.

Funny, you mention this. I got impatient recovering from TKR and made too much effort to increase range of motion for knee, or, in effect, drive length. I hate to admit that I've caused hip pain and a doc just told me: SI joint strain. First rowing related issue in 14 years. Pretty stupid actually. I'm looking at months more of recovery. Nonetheless, drive length will be on my mind, just not obsessively.

ErgData needs a facelift for sure. Looking at rowing parameters is a big deal for serious rowers and ErgData comes up well short. I should be able to look at past efforts on the ErgData app - all parameters. I used ErgData many years ago, but stopped because of its shortcomings. Perhaps some of the other rowing apps are better. I'm wondering what entity does ErgData and how to contact.

Probably my drive length/height ratio is greater than from others, but this is related to many aspects pointed out by Tsnor. Drive length alone will not help for high output/performance, as long as you cannot apply force in each of the positions you go through.

How about an experiment. Row 10 mins or so and constantly monitor drive length and keep it at 124 cm [70% of 177cm]. Keep everthing else the same, like effort. What kind of results? Then do another 10mins with maximum drive length. Again, results? I'm thinking there will be a non trivial difference.

[Sakly]

Probably my drive length/height ratio is greater than from others, but this is related to many aspects pointed out by Tsnor. Drive length alone will not help for high output/performance, as long as you cannot apply force in each of the positions you go through.

How about an experiment. Row 10 mins or so and constantly monitor drive length and keep it at 124 cm [70% of 177cm]. Keep everthing else the same, like effort. What kind of results? Then do another 10mins with maximum drive length. Again, results? I'm thinking there will be a non trivial difference.

If all other parameter stay the same (is it possible at all?), for sure, pace will drop significantly, as length gets lost.
The thing is, shortening a fluent movement you individually are used to, will have a similar effect as lengthening a shorter stroke, which individually is probably optimal, due to body metrics or ability to apply power, due to mobility. This is why stroke length has to be connected to other factors and will not stand for its own in terms of power/pace production.

[JaapvanE]

If all other parameter stay the same (is it possible at all?), for sure, pace will drop significantly, as length gets lost.

That will be a weird weak stroke indeed: as the drive length becomes shorter but drive time should remain identical, drive speed drops, making it just a weak stroke.

If you keep drive speed (and thus handle force) the same, you get a 3/4 stroke: a stroke focussed on the powerful part of the drive and recovery. It is typically used in race starts as it is a brutal stroke to execute but gets the boat moving fast. It is a less efficient (but more powerful) stroke that wastes a lot of good length to gain pace quickly. Even at Olympic races, you see teams abandon that stroke as soon as possible, as it isn't sustainable.

The thing is, shortening a fluent movement you individually are used to, will have a similar effect as lengthening a shorter stroke, which individually is probably optimal, due to body metrics or ability to apply power, due to mobility. This is why stroke length has to be connected to other factors and will not stand for its own in terms of power/pace production.

I have to agree here. It took me a year of focussed training to get rid of a weak back swing, with the added bonus of a lengthened drive. It is part of my stroke rhythm now: about 1 sec drive, about 2 seconds recovery (@ ~20spm), which governs my breathing. That rhythm also guarantees a good recovery and a strong catch. I couldn't go back, even if I wanted to.

Shortening up the drive without sacrificing power destroys that rhythm completely. Getting that good catch is difficult (that 2 seconds recovery combined with my DF guarantee a good catch). Breathing gets messed up, etc. Indeed, it isn't as simple as turning a knob somewhere with just that parameter.

[Cyclingman1]

I wasn't looking for perfection, but I think the experiment I proposed is quite feasible. Instead of coming up to the chain housing, stop a few cm's short and then pull back and layback as normal. It will take a few strokes to get a feel where the shortened stop point is, but that should be no big deal. Of course drive length is integral to the rowing overall. That's the point. and you would be a good test case given your normal 85% of height drive length. Take the time down to five mins, not ten. Of course, no requirement in the least.

[Sakly]

I wasn't looking for perfection, but I think the experiment I proposed is quite feasible. Instead of coming up to the chain housing, stop a few cm's short and then pull back and layback as normal. It will take a few strokes to get a feel where the shortened stop point is, but that should be no big deal. Of course drive length is integral to the rowing overall. That's the point. and you would be a good test case given your normal 85% of height drive length. Take the time down to five mins, not ten. Of course, no requirement in the least.

I think such an experiment should consider trying to get the same average and peak forces in the shorter stroke. In that case it would iron out the other factors (at least reduce their impact much) and the outcome would show the pace difference based on the different stroke lengths.
I can try to get that. Perhaps I'll have a go in the gym warmup today or in my steady session tomorrow. Best way to cut the length would be less reach at the catch and less lean back, as I think this replicates best what people do with shorter stroke length. It's probably impossible for me to cut 30cm at the catch

[Cyclingman1]

give it a shot.

[Sakly]

give it a shot.

Sorry, had to take another week off, so the test took place today. I did 10min "cooldown" after a 20x 1min on/off session, so HR was already on working level and could probably show the difference in effort.
First 5min I did on my usual stroke length, varying from 1.51-1.54. This showed a peak force around ~640 and average of ~460-480.
Second 5min I shortened the stroke to 1.3-1.36, it varied a bit more and it was a bit difficult to do such short strokes in the beginning. Left some room at the catch and reduced lean back at the finish, overall much less hip rocking than I do usually. I tried to really match the forces of ~470 and peak of ~640 and this worked well, as far as I can tell.
In the beginning it was also a bit difficult to hold the rate of 20 like I did in the first 5min, as the shorter strokes take less time for a complete drive+recovery phase. But after some strokes I could adapt that factor as well.

The result is:

Code: Select all

Time	Meters	Pace	Watts	Cal/Hr	S/M	❤️
10:04.7	2,479	2:01.9	193	963	20	152
5:00.0	1,254	1:59.6	204	1003	20	155
10:00.0	1,210	2:03.9	184	932	21	149

Ca. 4s/500m slower, effort lower, which is to be expected.
Due to the reduced length, rate could easily compensate for that, but obviously only to a certain degree. I think r22-23 on the shorter stroke would give the same pace. Overall, the shorter stroke at the same rate and forces gives a slower pace, but this was obvious. If someone is limited in mobility or is a really short person, rating up for same paces is a must.
Probably this was already clear before my test