I’ve never had this HR response for my intervals and looking for some knowledge about what causes a spike in HR right at the end of the longer intervals? This was 10-8-6-4-2’ running at ~threshold pace steady on a treadmill.
It would help to align the HR trace with effort. Cadence, for example. I often get a group of irregular heart beats as soon as I back off a hard effort. Those might be seen as a rise in HR, and AFAIK perfectly normal. OR, it could be that you are anticipating the end of the rep and pushing a little harder.
HR can and frequently is time delayed w/ actually energy output. Look at the acquisition circuitry involved in getting it: a moving chest wall, e.g., variability associated with with the motion of respiratory depth as a function of energy output, slippage of the strap sensors, and, the efficacy of the sensors themselves in acquiring the signal, translating it, uploading it to the data readout, etc.
I find it most helpful to be able to see in real-time (sic) the relationship among ECG, Br/m, HRV, Cardiac Strain (ST segment morphology and chronometry), HR, and energy output. I have used Polar H10, Garmin’s duoPRO (?), Movesense MD, and finally found that I get more useful data upon which I can act during the workout from FourthFrontierX2.
Full disclosure: I’m pushing 87 yoa w/ an almost 50 year Hx of endurance work couple with negatively accentuated HIRT. That Hx has done a great job of creating right ventricular cardiomyopathy, an enlarged aortic segment, and SVT ectopia, aka Athlete’s Heart.
So, if I’m to continue living, I need all the useful, actionable in the moment observable data I can get. The aging athletes with whose trainer’s I’ve consulted have found that advice useful. In that context, I did 1hr 28’ on FulGaz’s ride through Gettysburg ¶ National Civil War Monument site. Only 10.2 miles, but I did it. 80/20 sure does work for me as to safety.
I now advise all who might want to know: don’t take any single parameter as definitive. I hope that Podgacar et al are getting serially repeated aortic CT scans with contrast. A blown anyeurism and we are DRT (dead right there). And the symptoms are silent, until they are not, and then it’s too late.
Tony