Coach Thrasher

Syncing Applied Power for a Faster Boat

We've talked a little about synchronizing our power output profiles using Concept-2 PM3 monitors, but we haven't tried to actually do it yet. My hypothesis is: if we train to have matched power curves, where the slope of the curve through the stroke (or the graph of the derivative of force/time) matches for all rowers, we will increase overall boat speed. Or in other words: if each rower is able to apply their maximum power at the same time as other rowers in the same boat, the boat will go faster overall than if the maximum force is applied by each rower at a different time.

I believe this is true because the the total average (averaged by 8 athletes) force being applied will reach a maximum at the same time if power curves are matched. Another consideration for this is the rate of increase of force from the catch to max, and decreasing from max to the release, will be balanced between the port and starboard side. The balancing of force between port and starboard in a sweep boat should help set the boat, which in turn provides a more stable platform in the boat for the sweep athletes to apply force from. If the athletes have a stable platform, they should be able to apply more force, which will also contribute to boat speed. Therefore all of these elements are related.

Reading around on the web I found the Rowperfect "Synchronize Your Crew" webpage which references a study done on men's and women's crews. The most interesting item on the Rowperfect webpage is the opening statement: "A crew using synchronized power curves is up to 5% faster than a crew producing similar power, but discordant power curves. The longer the race, the greater the difference." But where do they get this 5% number from?

The Rowperfect page gives nice power graphs for novice crews before rowing together for a long time, and after rowing together, and presumably trying to match power curves using the Rowperfect device. This doesn't clearly show that the resulting matched power curve is a result of using the Rowperfect though. Is it possible that the matched power application was a result of simply rowing together on the water? I want to believe that using the power curve graph from the Rowperfect provided instant training feedback to the athletes on the machines, and this changed their technique and power curves to match. To really prove that, we'd need to have three groups of rowers: 1) only rowing on the Rowperfect, 2) only rowing on the water, and 3) using the Rowperfect and rowing on the water.

What about matching strong athletes and weaker ones? By focusing on the -slope- of the force curve, we can focus on matching timing of the applied power without worrying about the amplitude of force applied. That would allow strong and less-strong athletes to focus on the shape (or quality) of the curve to the crew's "ideal" shape. So, if the slope of the curve is matched for all athletes through their stroke, then generally they will hit the maximum force at the same time.

New athletes to our high school level program usually share two traits: 1) they've never rowed before, 2) they've done some other sport. I think it would be easiest to synchronize power application if everyone's muscles were balanced equally between the athlete's bodies. For example if: Johnny weighs 200 lbs, squats 400 lbs, and his squat to bench-press weight ratio is 2:1, and if Davey weighs 170 lbs, squats 200 lbs, and his squat to bench-press weight ratio is 2:1, then: one athlete is clearly stronger than the other, but they have the same strength balance in their bodies. If we have a former gymnast who is 170 lbs, squats 200 lbs, but has squat to bench-press ratio of 1:1, he will apply maximum power at a different part of the stroke than the other two athletes since his muscle's aren't balanced in his body in the same way. (Here I'm arbitrarily using squat to bench-press ratio as a rough measure of muscle balance.)

Okay, so is there a conclusion from this rant? I don't think there's enough published information to prove that sync'd force curves are ideal, but I'd like to try it. To do that I'd need:

• take data from PM3, and transfer it to a computer (every stroke? we only have PM2s and PM3s)
• determine the ideal curve for our boat (average of all curves, or best curve?
• render the curve for each athlete to see (use a transparency and magic marker to overlay the PM3 graph?)
• reinforce the ideal stroke by training power-application timing (drills)
• compare pre-matching to post-matching over 2k race times (hard because athletic ability will also improve boat speed while learning to sync force curves)

If anybody reading this has any idea of how to do this better, please let me know!

Posted at 03:00PM Feb 05, 2006 by jason in Rowing  |  Comments[0]