A discussion about rowing "SPI"

General discussion on Training. How to get better on your erg, how to use your erg to get better at another sport, or anything else about improving your abilities.
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hjs
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Re: A discussion about rowing "SPI"

Post by hjs » November 4th, 2020, 5:01 am

Yankeerunner wrote:
November 3rd, 2020, 6:40 pm
One last (probably) word from me on SPI is that my recollection is that Paul Smith thought it useful in putting together team boats. For instance, way, way back when I was capable of doing sub-7:00 for 2K I wasn't necessarily a good fit in a boat with other sub-7 rowers. In order for me to go that fast I needed to row at 37-38spm for most of the race and kick in the last 500 at an ever increasing rate of up to 48. Most other rowers would accomplish what I did with a much lower stroke rate. Testing me using SPI would probably mean putting me in a different boat than other sub-7 rowers, much to the relief of those who could generate that pace at 30-32spm and would find me to be an anchor at that stroke rate.
Not for Nothing Rick, otw people often train/test at given spm. That way you get around this problem.

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Re: A discussion about rowing "SPI"

Post by hjs » November 4th, 2020, 5:04 am

flatbread wrote:
November 3rd, 2020, 6:14 pm
I know that very smart engineers developed the C2 erg -- but, my experience with powermeters (I first used SRM in '98, and have used a variety of devices since then) makes me ask "where's the strain gauge?" "how do you calibrate this?" "how do you know it's accurate?"

looking at watts, or watt minutes, is interesting -- but what's the way to check the calibration and accuracy of an individual C2? Or, is it like a turbo trainer for the bike -- it has a predictable power curve, and the PM5 does the calculation based on flywheel speed, but it's just an estimate, not a direct measurement (with a calibrated strain gauge).

(which is a perhaps obtuse way of asking "why not just look at pace?")
There is indirect evidence. Nobody ever gets funky results. Nomatter what you do, you would get magical numbers out of the machine. You get what you are worth.

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Re: A discussion about rowing "SPI"

Post by Allan Olesen » November 4th, 2020, 5:17 am

Citroen wrote:
November 3rd, 2020, 9:19 am
That's the original reason Paul Smith came up with the meaningless, unitless "SPI" value in the first place.
I don't know Paul Smith, but the SPI is certainly not unitless. The unit is WattMinutes per stroke. One WattMinute is 60 Joule.

So it is a measure of energy per stroke. Perfectly valid.

However, at lot of people describe it as "power per stroke" or "Watts per stroke", and that is meaningless.

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Re: A discussion about rowing "SPI"

Post by lindsayh » November 4th, 2020, 5:58 am

Yankeerunner wrote:
November 3rd, 2020, 4:52 pm
Rocket Roy Brook became a world champion and world record holder with Paul as his coach. And so did Dennis Hastings.
I wish Paul Smith was still on the forum offering good advice.
The other guy I remember Rick was an Irish guy Jonathan Davis (40+lwt) I think was his name who embraced the whole thing and did some amazing training as Henry describes - 8ks with bumps in every 1k with 10mps as the goal. he won in Boston several times and got very close to WR
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Re: A discussion about rowing "SPI"

Post by ampire » November 4th, 2020, 5:25 pm

hjs wrote:
November 3rd, 2020, 4:55 pm
faach1 wrote:
November 3rd, 2020, 3:44 pm
May someone enlighten me by explaining who Paul Smith is? (The SPI “creator”)

What are/were his edging credentials? Etc..
Mostly the guy who invented 10 mps training. Meters per stroke. Only a limited number of people used it.
Most training strapless.
10 mps means no low rate work.
Most sessions 6/8k. Often with speedbumps.

It can get you fit pretty rapidly. Sessions are relative short.
What does the typical 6 or 8K session look like? Does speed bump mean that every 1K or so you increase your wattage?
M34|5'8"/173CM|150lb/68KG|LWT|MHR 192|RHR 42|2020: 5K 18:52.9 (@1:53.2/500)|C2-D+Slides+EndureRow Seat

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Re: A discussion about rowing "SPI"

Post by hjs » November 5th, 2020, 3:54 am

ampire wrote:
November 4th, 2020, 5:25 pm
hjs wrote:
November 3rd, 2020, 4:55 pm
faach1 wrote:
November 3rd, 2020, 3:44 pm
May someone enlighten me by explaining who Paul Smith is? (The SPI “creator”)

What are/were his edging credentials? Etc..
Mostly the guy who invented 10 mps training. Meters per stroke. Only a limited number of people used it.
Most training strapless.
10 mps means no low rate work.
Most sessions 6/8k. Often with speedbumps.

It can get you fit pretty rapidly. Sessions are relative short.
What does the typical 6 or 8K session look like? Does speed bump mean that every 1K or so you increase your wattage?
6k where often sort of time trials. Always relative fast, sometimes max.
8k a bit easier, but again, always firm.

Rating was based on 10 mps. Every stroke started when the m said 0. So at 20, 30, 400, 630 etc. The faster the rower the higher the rating.
No straps used, except for races.
Speedbumps where around 2k pace. Often at 9 Mps.

This is from memory, so can be a bit off.

Speedwork, was often.
2k wu, fast 2 min rest.
8x 500 2k pace, 2 min rest
2k fast again.

Or 3x1k every 1k done as a “mini” race. Pacing like you would do a 2k race.

All session 10 mps, except races, which where free rate.

Baseline testing as 1 min on, 1 off, goal every rep 1 sec. faster with 1 second. This untill a double failier.
So 2.00, 159, ..... 144, fail, fail. Session over.

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Re: A discussion about rowing "SPI"

Post by ampire » November 5th, 2020, 9:45 am

hjs wrote:
November 5th, 2020, 3:54 am
ampire wrote:
November 4th, 2020, 5:25 pm
hjs wrote:
November 3rd, 2020, 4:55 pm


Mostly the guy who invented 10 mps training. Meters per stroke. Only a limited number of people used it.
Most training strapless.
10 mps means no low rate work.
Most sessions 6/8k. Often with speedbumps.

It can get you fit pretty rapidly. Sessions are relative short.
What does the typical 6 or 8K session look like? Does speed bump mean that every 1K or so you increase your wattage?
6k where often sort of time trials. Always relative fast, sometimes max.
8k a bit easier, but again, always firm.

Rating was based on 10 mps. Every stroke started when the m said 0. So at 20, 30, 400, 630 etc. The faster the rower the higher the rating.
No straps used, except for races.
Speedbumps where around 2k pace. Often at 9 Mps.

This is from memory, so can be a bit off.

Speedwork, was often.
2k wu, fast 2 min rest.
8x 500 2k pace, 2 min rest
2k fast again.

Or 3x1k every 1k done as a “mini” race. Pacing like you would do a 2k race.

All session 10 mps, except races, which where free rate.

Baseline testing as 1 min on, 1 off, goal every rep 1 sec. faster with 1 second. This untill a double failier.
So 2.00, 159, ..... 144, fail, fail. Session over.
Thanks for the info, I can see how that would build a strong rower quickly.
M34|5'8"/173CM|150lb/68KG|LWT|MHR 192|RHR 42|2020: 5K 18:52.9 (@1:53.2/500)|C2-D+Slides+EndureRow Seat

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Re: A discussion about rowing "SPI"

Post by lancecampeau » November 16th, 2020, 11:05 am

I wanted to share a specific instance where I use SPI in training... injury recovery

Recently hurt my lower back on the right side (while bending over to scrub a toilet of all things :evil: ). In any case, this minor, nagging injury has temperately reduced my ability to generate power at lower stroke rates. This is where SPI recordings in my logbook come in handy.

My plan for today is a modest 5 x 1500m/2:00r @ 2:05. Normally I would do this work at r19 / DF 135 (SPI 9.43). However, with my back still being a bit tender, I will re-target the session for SPI 8.18 (r22 / DF 115) to slightly reduce strain on my back as I recover from the injury.

This small reduction in SPI will reduce mechanical stress on my back by spreading the target workload over a high number of stokes per minute. The trade off? I'm forced to waste energy moving my own body weight back to the front of the rower 93 extra times during the session[/i].

- 5 x 1500m @ 2:05 = 30 min 45 secs of rowing
- 30:45 @ r19 = 584 strokes
- 30:45 @ r22 = 677 strokes
- 677 - 584 = 93 extra strokes

Its not really "high science"... you're essentially trading brute force per stroke for increased aerobic endurance, something we do all the time on the rower (I.E. rate creep). Despite a small decrease in rowing efficiency, this simple approach will allow me to maintain my target pace for today's session while recovering from an injury and is one example of how I use SPI in my training program.
Male, 46, 6ft / 240 lbs, 183cm / 108 kg / Started erging in Jan 2017
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Re: A discussion about rowing "SPI"

Post by frankencrank » December 2nd, 2020, 3:03 pm

SPI seems to me to be pretty worthless. How does it help you? It seems to me a better index would be the Stroke Efficiency Index. That would be Watts divided by HR at the various power and stroke rate. HR is a good proxy for oxygen consumption. So, the higher the SEI, the more efficient one is. This would be a useful tool, I would think, for any aerobic (not sprint) effort.

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Re: A discussion about rowing "SPI"

Post by hjs » December 2nd, 2020, 4:17 pm

frankencrank wrote:
December 2nd, 2020, 3:03 pm
SPI seems to me to be pretty worthless. How does it help you? It seems to me a better index would be the Stroke Efficiency Index. That would be Watts divided by HR at the various power and stroke rate. HR is a good proxy for oxygen consumption. So, the higher the SEI, the more efficient one is. This would be a useful tool, I would think, for any aerobic (not sprint) effort.
It should he used in context, just the number itself means

It should be seen in context what it is during a race. In combination with dailing down rating, spi can be kept while you use a hf cap and do aerobic training.
Just looking at spi as an absolute number says something about ones power. For max pace/sprints a high absolute number is an important marker.

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Re: A discussion about rowing "SPI"

Post by jamesg » December 3rd, 2020, 2:51 am

Watts/Rating is Work done in the stroke, whatever you call it; and Work = length x average handle force. Ergdata shows both, with some approximation.

SPI meant Stroke Power Index, and this too was Power/Rating; so effectively a misnomer: (Work/Time) / (1/Time) = Work.

Failing a coach or a video, this number can be useful to a beginner when learning to use the erg; the rowing style ** we learnt 60 years ago does not come automatically on the erg, where the constraints due to water (and coaches) are not usually present.

** from fast release slowing at the catch to slow release accelerating to the catch
08-1940, 183cm, 84kg. Last seen MHR 155, in 2k (2020-12-03) 8.47.6@23

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