Evan Snyder writes: Most of us have done the arms/arms+body/Half slide warmup exercise drills on the water, but the contribution each element has
to your rowing stroke may surprise you. Years ago, Rob Waddell said in an interview that the power generated in a rowing stroke was in a ratio of 60% legs, 30% back 10% arms. I have now conducted both the Ergometer and the on the water tests to determine just how much contribution each muscle group has to the rowing stroke.
Experimental Methods
- Each element was done over 1 minute of time (erg and water).
- Legs only = keep back at the catch position and arms straight, push legs down from vertical shins to flat
- Back only = legs flat, arms straight and rock back from catch to finish position
- Arms only = legs flat, back at finish layback, draw arms from straight to finish
Results (Erg – 2 trials)
- Legs only = 200 metres / 1 minute at 35 spm; 219 metres/ 1 minute at 39 spm (36.7% 35.8% respectively)
- Back only = 175 metres / 1 minute at 34 spm; 206 metres/ 1 minute at 42 spm (32.1% 33.7% respectively)
- Arms only = 170 metres / 1 minute at 39 spm; 186 metres/ 1 minute at 51 spm (31.2% 30.4% respectively)
- Total distance 545 metres; 611 metres in 3 minutes (averages = 177.6m 203.7m / 1 min respectively)
- Total distance for normal rowing over 3 minutes = 678m
Results (Water – 1 trial)
- Legs only = 165 metres/ 1 minute at ca. 30-35 spm (40.7%)
- Back only = 125 metres/ 1 minute at ca. 30-35spm (30.9%)
- Arms only = 115 metres/ 1 minute at ca. 30-35 spm (28.4%)
- Total distance = 405 metres (average = 135 m)
- Total distance for normal rowing over 1 minute = 215m (x 3 = 645m)
Analysis of results
- Legs only = 35.8% 37.54% (erg) vs 40.7% (water) of total distance (compared to 60% predicted)
- Back only = 32.1% 33.7% (erg) vs 30.9% (water) of the total distance (compared to 30% predicted)
- Arms only = 31.2% 30.4% (erg) vs 28.4% (water) of total distance (compared to 10% predicted)
Proof
In this “gem”, on slide no. 15 it shows the % of power produced by the Legs, Back Arms. Dr. Kleshnev’s values (on the water) are: 46.4% Legs, 30.9% Trunk (back), 22.7% Arms (based on around a 30 spm rate with legs% increasing with stroke rate, trunk% staying constant and arms% decreasing)
My values for on the water were: 40.7% Legs, 30.9% Trunk (back), 28.4%
Conclusions
A) While not doubting the anecdotal comments, nor experience of Rob Waddell, it might be an interesting exercise for all rowers to find out how much of each muscle groups they are using in their rowing stroke. In my case, contribution of the back is quite close to Rob’s predicted level. However, the arms played a significantly larger contribution, while the legs less so.
Is this an anomaly or is the contribution of the arms more than what was previously thought?
It is interesting to note that on the water vs the erg, the legs seem to play a greater part of the stroke and the arms less so. On the erg there is no penalty to be paid for pulling (hard) the small, straight handle straight to the body just under the xiphoid process, whereas in a sculling boat the two handles begin in front of the body, but are pulled up beside the trunk just at the bottom of the rib cage which does require a bit more “finesse.”
B) When rowing normally for 1 minute on the water at 30 spm, I completed 215 metres. Corrected to 3 minutes this is 645 metres which is significantly higher than the 405 metres for the sum of; legs only, back only and arms only water distances. Similarly, on the erg, I had done 678 metres for 3 minutes. This is also much greater than the 545 and 611 metres for the sum of; legs only, back only and arms only erg distances from those trials.
Both on the water and on the Erg, these results illustrate the “Gestalt” effect of the rowing stroke, i.e. the total being greater than the sum of the parts. This, in my view, is also a justification for the concurrent (force application) or classical style vs. the sequential (force application) or modern orthodox style.
Rowperfect reponse – how to teach and improve
Anyone wanting drills to do that improve co-ordination as you transition from legs to back and back to arms may want to try these exercises (each link explains how to teach the drill and what to expect from it). Practicing these can help you to harness more muscle power to your stroke.
Arms and Body Rowing – helps build more power towards the finish of the stroke and ESPECIALLY good for masters who don’t use their back muscles for boat power!
Slide progression from front stops – helps lengthen the stroke in the water and co-ordinate each part
And as a final comment on Evan’s analysis – he has not weight adjusted the ergo score which may change the result compared to the on water distance.
This Post Has 10 Comments
Why don’t you measure power displacement/time dependence in normal rowing, fit it with a polynomial, then integrate it and see how much energy each phase creates? That was a quick thinking i guess you would get the same result, but still for me it looks like stroke is equivalent of acceleration, so you can measure energy for each phase of stroke by calculating drag and differences in velocity of a boat. I guess that would result in much higher contribution of legs since at the begining of a stroke the boat is slowest.
I have to dispute this analysis in terms of which body movement provides what percentage of power. The problem is using arms/body/legs only strokes means that each body movement stats at the slowest point of the stroke unlike the complete stroke where each body part starts taking on the pressure at a progressively faster boat speed and thus does less work accelerating the boat. Thus the legs will do more work and the arms less.
true story bro
It’s interesting reading, but I also have to agree with the comments at the end. The boat is at its slowest at the catch and your legs has to accelerate the boat, therefore more pressure on the legs. The back and arms come into effect when the boat is at its max velocity
I think it’s possible Evan’s personal rowing style may be more arm dominant
There is another way in which to look at the relative percentage of each body part.
Look at the rower’s force profile on the RP display, in particular, the percentage of the stroke the maximum pressure occurs.
A front loaded curve, i.e. max force at 30% or so, will be a high leg percentage.
When the max force moves back to 40& and greater, the back has a greater percentage.
An if the force curve does not drop off in the last part of the stroke, the arm percentage increases.
All this has to do somewhat with the rower’s physiology. A rower with strong legs will be more front loaded. A rower with stronger back or arms will be more symmetrical.
The rower can be trained to alter their force curve to eventually develop a more symmetrical force curve. And in a crew boat, all rowers should have a compatible force curve, or they are wasting the strongest rowers efforts at each part of the stroke where they are stronger than their boat mates (with the exception of sweep boats where the bow side and stroke side rowers need to row with dissimilar force profiles)
If we derive the power delivered from the speed measured (or displayed on the erg) then the results get closer to Bob Waddells statement, for what it’s worth.
Power in rowing is proportional to the third power of speed (speed cubed).
On the erg we find 44, 29 and 27% for leg drive, body swing and arms, and the complete stroke gives only 63% of the sum of the powers of the parts, not surprising because blood circulation must now be divided between muscles.
On the water we find 56, 25 and 19% of the sum of the power of the parts and the complete stroke gives 125% of the sum. I think that on the water arm drive and body swing performed in isolation are less effective because entry and finish are not instantaneous, as they are on the erg.
And since leg drive and body swing depend on the same muscles, what’s the use of separating them?
In addition to Bert’s points (you should be working in power/energy, not distance), you should also be rowing at the same stroke rate for each of the three components and your complete stroke. Your spm is all over the place (30-51spm), and lowest for the complete stroke, which is why the sum of the work done for each of the individual components is greater than for the complete stroke. Your arms% will get even lower if you rerun the trial doing everything at 30spm.
(Unless your normal rowing is your arms going at 51spm and your legs going at 35spm, which sounds hilarious, vid please)
Greetings,
Presumably the ‘work’ is muscle force x distance travelled, which is fine if the muscles are actually moving. However in us humans a muscle can be powered and tiring, without moving.
So the back, even if not moving to a layback, is still loaded with the power of the leg drive(L). In addition the back muscles have to deal with the weight of the torso(T) if you remain leaning forward after the catch. Force on back = L+T.
My ‘RHECON’ sculling style therefore recommends that you layback at the catch – by rotating the torso above the hips. The force on your back from the leg drive will now be L – T.
Noone sensibly pulls something while leaning forward, so why are rowers taught to only layback after the main work is done?
While you’re at it save more energy by letting the back curve comfortably always. Finish the leg drive and arm drive together and don’t hold the legs down. Feather while, not after, the blade leaves the water(feather drives the boat). 2 breaths per stroke always. Heel blocks so heels never lift- less calf muscle use. Arms only straightened fully-by blade momentum- at the catch, not during the recovery.. Square at the catch, not before.
Have fun.
I am not rattling great with English but I find this real leisurely to read.