Not all LPT’s were created equal.
How does GymAware compare to the Tendo FitDyne?
If you are an existing Tendo Power and Speed Analyzer from TendoSport user then you will already know the value of speed and power measurement while weightlifting. But how much better can it be? The GymAware PowerTool is designed by engineers for sports performance professionals. Check out the feature comparison table below.
While this is a good comparison between GymAware and the Tendo Unit , it doesn’t really capture the pleasure of using GymAware. The wireless iPad interface offers so much more to the coach and athlete, with its simple graphical display, touch screen interface and all the other usability features you have come to expect from Apple devices. Why would you settle for anything less?
▪ Accurate and reliable
▪ Works with Apple iPads
▪ Measures angle of lift, compensating for non vertical movements
▪ Automatically detects the concentric lift phase of all lifts and jumps
▪ Uses state of the art Variable Rate Sampling (VRS)
▪ Can measure a greater range of movements than a force plate.
GymAware is the Linear Position Transducer For Sport.
An LPT or Linear Position Transducer measures distance (Position) and time to calculate velocity and power. The GymAware PowerTool and the Tendo unit are types of LPT. But that is where the similarity ends. The PowerTool uses a constant spool size mechanism to prevent inaccuracy due to tether over-wind, and measures angle of lift to compensate for non vertical movement.
What is cord over-wind?
As the tether is pulled in and out of the sensor unit, it un-spools and re-spools onto the tether spool. The position and speed of rotation of the spool is then used to calculate your lift measurements. If the tether is allowed to wrap over itself as it re-spools then the diameter of the spool increases by the twice diameter of the cord for every tether over-wind. This effectively means that speed and power measurements will vary in accuracy depending on how much tether is drawn from the device! It can’t be corrected in software as you can never be sure when the tether is over-winding. The error will be very significant and will change depending on the length of the movement being measured.
The only way to correct over-wind is to prevent it.
The PowerTool has a special spooling mechanism that moves the spool as it winds so that the tether is never allowed to wrap over itself. This ensures that the spool diameter is kept constant no matter how much tether is pulled form the unit. The Tendo power and speed analyzer has no such mechanism to prevent tether over-wind.
What about errors due to angle of lift?
Many weightlifting exercises have a horizontal component to them yet most LPTs have to assume that the entire movement is vertical. The GymAware PowerTool measures the angle of the tether as the displacement is recorded, and then calculates the vertical component of the lift.