David Butcher: PPPM and the Science of Pedal Power
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PPPM Pedal Generator Output Metrics - Human Power Output Data
Chart of PPPM Pedal Generator Human Power Output Experiment Results
The chart shows the results of the experiment. All values are plotted to show how they vary in relation to each other. The bottom scale represents two-minute measurement intervals - one minute of measurements and one minute of data recording and preparation for the next power level. The left scale represents the values of each measurement. The easiest metric to follow is Watts, beginning at one Watt, climbing to 110 Watts, and then descending to 1 Watt again over the time frame of the experiment. All other measurements are relative to Watts of output.
Notes: We forgot to tally Watt-hours until we were are the second 100 Watt level. This metric can be safely interpolated, however, as it is the result of a specific power output for a specific time, and both of those numbers are known.
Our technique for counting breaths changed at the first 100 Watt level. We had been relying on David to make a "clicking" sound on each breath, but it turned out his breathing could be directly counted simply by listening to the sound of his exhale. The breaths/minute numbers are probably more accurate after the first 100 Watt level.
After the experiment was over, David demonstrated two 30-second sprints at 130 Watts, with 2-3 minutes of a 75 Watt pace between the sprints. The only metrics collected for the two sprints were cadence and heart rate:
All metrics shown were collected using the PPPM I with a single generator. A future experiment may be conducted (if several more motivated individuals will participate!) using the PPPM I with double generators. That experiment will enable David's top level of sustained power output to be measured.
Other technical information: