There’s a technique that we use when riding a horse that likes to pull on the reins or “lean” on the bit, to stop the horse from doing this. Basically in this situation the horse is putting its weight into the rider’s hands which is not just tiring on the arms, but tends to pull the rider off balance, not good either party. The technique is simply to “throw away the hands…” which is literally letting go of the pressure the horse is experiencing by moving the hands towards the horse’s head. This use the principle of force velocity to increase the velocity of the bit—forward—which takes the force development available to the horse to close to zero. This is the same principle of an Akido master moving with the weight and force of an opponent to create zero force development.
You’ve probably walked a dog in your life with one of those leashes that come out of a drum when the dog pulls on it. You don’t feel the weight of the dog pulling on the leash as it’s unwinding from the drum because of the velocity. Once it hits the end though you’re sharply reminded of how much your dog weighs—force of the dog.
If you’ve ever had to push a car to jump start it you’ve experienced this. At first the car is still velocity of the car is zero, the force of the car is maximal—its weight—as you lean into it, with three of your friends, you start the car moving and it starts to feel lighter. At some point the car is moving fast enough that you can no longer apply a force to it, it feels weightless and slips away from you.
This chart relates the force – velocity relationship. When the velocity approaches zero the force applied is maximal. As the velocity of the object increases the force applied decreases. At maximum velocity the force approaches zero. This chart shows the training relationship of a force and its velocity. One can not move a 1 repetition maximum force quickly—this is why the coaches will tell you to put more weight on the bar if you lift it too fast in a rep max test. If you want to train to move a heavy object quickly you’ll train in the 75-90% of your 1RM.
For pure power you’ll train at 40-60% of 1RM, etc.
If you’ve ever ridden a bicycle downhill you know what Speed-Velocity feels like, it’s a little hard to keep your feet on the pedals, even clipped in, and your push on the pedal does not add much to the motion.
On the Concept 2 Rower we experience the same physical properties. When we first pull on the handle the fly wheel is at rest so we experience the zero velocity point, the force required to move the flywheel is maximal—for the fly wheel resistance. As the flywheel is moving, the velocity is increasing, it is easier to pull it. However, while the flywheel is easier to move at this higher velocity we don’t add much to the its motion. We want to wait for the fly wheel to slow down a bit so we can add more force to it. We want to be in the power range of the curve.
In an Olympic lift we move the bar from the ground relatively slowly to position it more optimally for our body to apply maximal force against it and to accelerate it to where it will require less force to get under it. If we “yank” the bar off the ground achieving a maximal velocity early we’ll lose our force application advantage, and when we try to “pull” the bar the force will be reduced.
So, the next time you want to know how much weight you should put on a bar think of your objective for the lift and then use this type of chart to pick the force.