One problem with the Garmin Edge 800 ‘bike nav’ is that unless you press the reset button between rides it assumes the activities are linked and makes them continuous. And so my 30 mile cycle ride this weekend was automatically joined to my midweek 20 minute resting heart rate test.
This presented me with a problem when trying to calculate my average heart rate from the ride. A problem requiring an algebraic formula! Knowing the mathematical inclinations of my readership I thought I would present my formula for comment.
Total Heart Rate, HRt = 143 bpm
Total Time, T = 2 hours & 17 mins = 137 mins
Midweek Resting Heart Rate, HRr = 65 bpm
Midweek Resting Time, Tr = 20 mins
And now a brief interlude to allow you to produce your own formula(e) to calculate my ride average heart rate, X.
My initial (incorrect) attempt was: (Tr x HRr) + ((T-Tr) x X) = HRt
This didn’t compute so I realised I had forgotten to divide the left hand side by the total time, T to give the average.
My second attempt was thus:
Fairly straightforward I suppose, but good to get the maths brain working again.