Does racing at a lower drag than when training make a difference?

[Nomath]

Sorry for quoting you sloppily, but I do not feel that the missing word adds some relevant meaning.

You quoted what was written in the abstract of the 2008 paper :
"Comparing across all six submaximal stages showed no significant differences between DF100 and DF150 for any of the variables measured (p>.05). Maximal [..] stroke rate were greater at DF100 than at DF150, but not significantly so."

I believe the authors underestimated the significance of their results.
My university classes in statistics were decades ago, but if you take 'Average stroke rate at D100 is NOT higher than average stroke rate at D150 for a group of 10-20 experienced rowers' as a testing hypothesis, a binary statistic, then having 6 observations where average SR@DF100 is higher then average SR@DF150, is highly unlikely, roughly p<0.02.
Adding the 2012 results, you get a highly significant result for a group of 10-20 experienced rowers. Of course, not every individual has to follow that group trend.

[Joebasscat]

Interesting experiment! You got the same stroke at the low drag factor as for the high drag factor. This seems different from....

The difference may be that both me and gvcormac were able to see the PM5 display showing stroke rates, and were attempting to manage our rowing to hit the stroke rates we wanted. If we'd been blind to pace/SPM etc not sure what the results would have been.

This study (which you also ref'd) found no substantial exercise difference between 100 DF and 150 DF https://www.researchgate.net/publicatio ... _of_Rowing
......

Tsnor, I am pleased to have such an attentive and critical reader!
Yes, I took the data from Kane's paper of 2012 to make my previous graph. So I hastened to plot the data of his 2008 study.
Here are the results for average stroke rate depending on power output at 100 DF and 150 DF :



So the 2008 data clearly show the same difference in stroke rate as the 2012 data !

You wrote "no substantial difference between 100 DF and 150 DF". Is the difference statistically significant? Looking at the spread in the data points in his table 2 (page 392), you can have reservations. The results are averages of a group of more than 10 participants. The 2008 group was clearly more heterogeneous (Max Power about 235 W ± 65 W ; in 2012 Max Power about 255 W ± 20 W). Probably also Kane refined his experimental approach.
If the difference between 100 DF and 150 DF were not substantial, you would not see two curves that are clearly and consistently separated at nearly all data points.

Would be interesting to see an individuals HR differences while producing the same power at 100 DF and 150 DF. As stated earlier, I have self imposed the 85 DF lately instead of my normal 110. On 60 minute rows I have no chance of holding same HR at same power and same SPM.

[gvcormac]

Would be interesting to see an individuals HR differences while producing the same power at 100 DF and 150 DF. As stated earlier, I have self imposed the 85 DF lately instead of my normal 110. On 60 minute rows I have no chance of holding same HR at same power and same SPM.

Please provide more subjective details. When you set out to maintain the same pace and stroke rate, your HR is higher with lower DF? Do you feel that's because your stroke is so fast you expend a lot of eccentric force slowing yourself down? Or you waste energy because of torso movement before your catch?

I would've thought the limiting factor would be fast twitch response, but I would think exceeding that would cause fatigue rather than HR elevation. Maybe I need to rethink that.

[JaapvanE]

Please provide more subjective details. When you set out to maintain the same pace and stroke rate, your HR is higher with lower DF? Do you feel that's because your stroke is so fast you expend a lot of eccentric force slowing yourself down? Or you waste energy because of torso movement before your catch?

I have played around with all DF's in the C2 range, and try to maintain around 20 SPM at a 6K steady state (validation of ORM's drag calculation). For me, I can reach the same speed at DF225 as I would at DF135. However, the strain on joints at DF225 is considerable so I wouldn't consider it sustainable for more than one session. Going down from DF135 the stroke becomes less effective at 20SPM and thus either pace or SPM have to change.

What I notice is that my drive length goes down from my usual 1.3 meters to 1.21 or even 1.15. My interpretation is that my legs are powerfull, but not fast, and thus you lose all effectiveness at the catch when you have a fast flywheel. The force curves show a short frontloaded stroke lacking power, suggesting I am quite far in the leg drive before the flywheel is picked up. As I see it, when drag goes down, you need more speed in the flywheel to do the same work, and at a certain point my legs can't keep up.

I would've thought the limiting factor would be fast twitch response, but I would think exceeding that would cause fatigue rather than HR elevation. Maybe I need to rethink that.

I think a huge difference is wether people are more reliant on muscle power or on speed by nature. For me, switching to a much lower DF is like trying to keep up in 1st gear downhill on a bike: my legs are moving and trying to keep up, but the lack of meaningfull resistance is whats bothering. For me, there is no fatique, I don't even sweat after a 6K at low drag. But my HR is all over the place.

[Nomath]

.....
Would be interesting to see an individuals HR differences while producing the same power at 100 DF and 150 DF. As stated earlier, I have self imposed the 85 DF lately instead of my normal 110. On 60 minute rows I have no chance of holding same HR at same power and same SPM.

I hadn't analysed this issue previously, but the paper in the Int. Journal of Sports Medicine by D. Kane from 2012 also provides the average data for a group. They were plotted by me from his Table 1. Participants were asked to row at a stepwise increasing target power except at the last 'all-out' measurement. They were free to choose the stroke rate. All measurements involve a 3-min exercise. The damping factor was set at 100 and 150. Please note that the participants in the study were 12 young college rowers aged 20.3 ± 0.4 yrs, male and female.

[Joebasscat]

Would be interesting to see an individuals HR differences while producing the same power at 100 DF and 150 DF. As stated earlier, I have self imposed the 85 DF lately instead of my normal 110. On 60 minute rows I have no chance of holding same HR at same power and same SPM.

Please provide more subjective details. When you set out to maintain the same pace and stroke rate, your HR is higher with lower DF? Do you feel that's because your stroke is so fast you expend a lot of eccentric force slowing yourself down? Or you waste energy because of torso movement before your catch?

I would've thought the limiting factor would be fast twitch response, but I would think exceeding that would cause fatigue rather than HR elevation. Maybe I need to rethink that.

I’d like to provide some, but all I have are my simple observations. Was performing SS at about 65% of max HR. With the change in DF it’s been closer to 70% and at the same time reducing from 90 minutes to 60 minutes. So reducing volume as well. I think the legs are forced to engage even more so because even with reduced drag, to maintain same pace it eventually feels about the same as before. In other words, still working to the extent you would expect for SS. Not on day one, but over a two week period. On day one it felt light, but not so much now. All at 20 SPM. I think once I work back to 110 DF I may be more efficient at the catch, having spent the time at 85 DF. What I’d really like is for this pain in my butt to relax Missing my hard intervals is bothersome. But lots of new stretches that seem to be providing relief, slowly.

[Joebasscat]

.....
Would be interesting to see an individuals HR differences while producing the same power at 100 DF and 150 DF. As stated earlier, I have self imposed the 85 DF lately instead of my normal 110. On 60 minute rows I have no chance of holding same HR at same power and same SPM.

I hadn't analysed this issue previously, but the paper in the Int. Journal of Sports Medicine by D. Kane from 2012 also provides the average data for a group. They were plotted by me from his Table 1. Participants were asked to row at a stepwise increasing target power except at the last 'all-out' measurement. They were free to choose the stroke rate. All measurements involve a 3-min exercise. The damping factor was set at 100 and 150. Please note that the participants in the study were 12 young college rowers aged 20.3 ± 0.4 yrs, male and female.

Thank you. Seems consistent with my personal observations.

[Nomath]

Thank you. Seems consistent with my personal observations.

I find the two papers by D. Kane in the Int. Journal of Sports Medicine real treasure troves for analysing the effects of the drag factor. If you look at the data in Table 1 of the 2012 paper (below), you see quite a big spread in the average of each variable. You would not expect to find significant effects because of this large spread. However, the spread is mainly due to the variation in athletic ability of the particants. Although they were of very similar age (20.3 ± 0.4 yrs), height (170.9 ± 2.2 kg) and weight (72.7 ± 2.1 kg), the power output in a 3-min 'all-out' exercise varied procentually much more : roughly 260 ± 20 W.



Yet, there are a lot significant effects of the drag factor in these data that you see more clearly when you plot them in a graph.
Statistics often involves a test of a so-called null-hypothesis 'Let's assume that a certain factor X has zero effect on a variable'.
If the null-hypothesis is true, an experiment is as flipping a coin : you expect roughly the same average result when the factor X is set at a low value as for a high value. But if, say, a low value of that factor consistently produces a lower or higher result than the high value, the null hypothesis becomes unlikely. A series of 7 comparisons that yield 7 times the same difference, is like flipping a coin 7 times and always getting heads: a chance of less than 1-in-100. There is probably something wrong with the coin. In our issue : with the null hypothesis.

Here is another remarkable effect of the drag factor : the oxygen uptake depending on power output. Oxygen uptake relates to the burning of carbohydrate stocks to produce the required output power



Observing this and the previously shown effect of the drag factor on stroke rate, one can go further : is oxygen consumption possibly related to stroke rate? If we compare at the same stroke rate, is the effect of the drag factor still there?
As you can see in the graph below, the evidence is now less clear.

[JaapvanE]

Here is another remarkable effect of the drag factor : the oxygen uptake depending on power output. Oxygen uptake relates to the burning of carbohydrate stocks to produce the required output power

Wouldn't that be consistent with the idea that increasing the dragfactor, you switch from a distance driven (aerobic) aporoach to a more power driven (anearobic) approach?

[Tony Cook]

I did an extension of @gvcormac ‘s experiment by trying 1k at five different drag factors.

Time Meters Pace Watts Cal/Hr S/M
20:06.4 5,000m 2:00.6 199 986 20 118
DF 180
4:01.3 1,000m 2:00.6 199 985 20 118
DF 150
4:01.7 1,000m 2:00.8 198 982 20 119
DF 100
4:01.3 1,000m 2:00.6 199 985 20 119
DF 120
4:01.0 1,000m 2:00.5 200 988 20 117
DF 80
4:01.2 1,000m 2:00.6 200 986 20 119
I don’t know what it shows but of interest to me was my heart rate pattern was virtually identical in every piece, so all equally hard/easy. I preferred the piece at DF 100 although I do all my rowing at DF 120-130.

[gvcormac]

I did an extension of @gvcormac ‘s experiment by trying 1k at five different drag factors.

Time Meters Pace Watts Cal/Hr S/M
20:06.4 5,000m 2:00.6 199 986 20 118
DF 180
4:01.3 1,000m 2:00.6 199 985 20 118
DF 150
4:01.7 1,000m 2:00.8 198 982 20 119
DF 100
4:01.3 1,000m 2:00.6 199 985 20 119
DF 120
4:01.0 1,000m 2:00.5 200 988 20 117
DF 80
4:01.2 1,000m 2:00.6 200 986 20 119
I don’t know what it shows but of interest to me was my heart rate pattern was virtually identical in every piece, so all equally hard/easy. I preferred the piece at DF 100 although I do all my rowing at DF 120-130.

Very interesting. Thanks for doing this.

Is the last number in each column HR? I think your are very fit if you can do it at that HR. Also, were these consecutive?

[Tony Cook]

I did an extension of @gvcormac ‘s experiment by trying 1k at five different drag factors.

Time Meters Pace Watts Cal/Hr S/M
20:06.4 5,000m 2:00.6 199 986 20 118
DF 180
4:01.3 1,000m 2:00.6 199 985 20 118
DF 150
4:01.7 1,000m 2:00.8 198 982 20 119
DF 100
4:01.3 1,000m 2:00.6 199 985 20 119
DF 120
4:01.0 1,000m 2:00.5 200 988 20 117
DF 80
4:01.2 1,000m 2:00.6 200 986 20 119
I don’t know what it shows but of interest to me was my heart rate pattern was virtually identical in every piece, so all equally hard/easy. I preferred the piece at DF 100 although I do all my rowing at DF 120-130.

Very interesting. Thanks for doing this.

Is the last number in each column HR? I think your are very fit if you can do it at that HR. Also, were these consecutive?

Yes, HR in last column. There was about 90 secs between pieces as I fiddled with the damper to try get it exactly on the required DF.
It’s made me think if longer pieces would effect HR differently so I may do, maybe 5k’s at wildly different HRs, and maybe different days, so there’s no cumulative effect.