I have a B type WPW pattern and my ECG does look peculiar. I say pattern as I am asymptomatic and my accessory pathway has been checked and is safe. I did go for an ablation but it was too close to the bundle of his and the risk of damaging it was too high considering I was basically asymptomatic. Anyway, the software isn’t smart enough to recognise a negative QRS complex and so thinks you have created little cardiac strain even after a 2-3 hour bike ride.

The top line is where the normal pathway is dominating at a higher HR and the bottom line is where my HR has dropped and the accessory pathway tends to dominate. BTW my cardiologist has looked at these traces and is quite happy that nothing it out of the ordinary for me and to keep going with my training. I race time trials on my bicycle.