jamesg wrote: ↑August 16th, 2018, 3:18 am
In general if resistance is proportional to the square of speed and power to the cube (as in air and water), overspeed is unsuccessful.
It is a common misconception that because resistance in rowing is proportional to the square of velocity and power to the velocity, overspeed will be unsuccessful. In truth, overspeed is unsuccessful primarily for physiological, not physical reasons.
Sorry to impose some math on you folks:
As an example, lets assume that we have a 6:00 flat 2k rower and that she rows even splits of 1:30/500m (0.18 sec/meter) . Per the Concept2 formula of:
watts = 2.80/pace³
pace = ³√(2.80/watts)
where pace is time in seconds over distance in meters
(ref:
https://www.concept2.com/indoor-rowers/ ... calculator)
Plugging in a pace or 90s/500m
watts = 2.80/pace³
watts = 2.80/(90 sec/500m)³
watts = 480.11
which given a time of 360 seconds to cover the 2k, the energy produced would be:
joules = Watts * time
joules = 480.11 * 360 s
joules = 172,839.60 J
Lets now assume, that she changes her race strategy and rows a pace of 1:27.5 for the first and last 500ms and 1:32.5 (a fairly common strategy at the world class level) for the middle 1k
The power required for the first and last 500m would be :
watts = 2.80/(87.5 sec/500m)³
watts = 522.45
which given a time of 175 seconds to cover the first and last 500, the energy produced would be:
joules = 91428.75 J
And the power required for the middle 1k would be:
watts = 2.80/(92.5 sec/500m)³
watts = 442.23
which given a time of 185 seconds to cover the middle 2k, the energy produced would be:
joules = Watts * time
joules = 442.23 W * 185 s
joules = 81811.54 J
or combining the first and last 500 with the middle 2k, a total energy produced of
joules = 173,240.29
which converting back to watt and assuming a time of 6:00 (360s) for the 2k
Watts = 173,240.29J / 360s
Watts = 481.22W
or a difference of 1.11Watts or 0.23%
We can also work backwards and assuming that our rower was producing 481.22 watts and rowed a 2k at an even pace, how much faster would she have been:
pace = ³√(2.80/watts)
pace = ³√(2.80/481.22W)
pace = 0.17986 s/m
Time for 2k
T = pace * 2000m
T = 359.72 s or 5:59.72
or the cost of using an uneven pace was only .28s or 1.55meters or 1.5 seats.
(The reason for this seemingly anomalous result is that in the region near a particular velocity, the power to velocity ratio will be fairly constant. )
>>>>>>>>>>>>>>>>>>
The problem with overspeed is that if you are not careful, it overtaxes the anaerobic system. Your body's flight of fight response says too much O2 debt, flight is not working so best to slow down and prepare to fight. Your heart rate drops and you can't get it up to maxHR until you breathe off some of the Oxygen debt.