HR Question

Team Banana Spokesman

why does it continue to increase over time even when im doing a steady pace?

normal?

sergen

Very normal and commonly known as 'cardiac drift'. When doing intervals at a consistent power one's heart rate will tend to drift upwards as the interval goes on. I'm not too hot on the medical explanation for why this happens but it's perfectly normal.

Bronzie

http://en.wikipedia.org/wiki/Cardiovascular_drift

One of the main drawbacks in using HR as a guide to exercise intensity.............if you ride at a constant HR, your power output will gradually drop.

shockedsoshocked

What he said.

Also as you do more exercise you lose water, blood becomes thicker, heart has to work harder even at the same pace.

Bhima

If you put food into a hot oven, it does not heat up immediately just as taking it out of the oven does not reduce it to room temperature immediately.

GavH

Body heats up - heart pumps a bit faster to keep it cool.

doyler78

Here's an example from last Saturday's 2x20 for anyone not sure what the OP is talking about. Power consistent to within a few watts throughout both intervals. Warmup could have done with being at least 5 mins longer but I didn't have time for that. My power didn't suffer so was very happy with the session inspite of the heat and scaled back warmup.

jgsi

Just trying to clarify
With indoor training specifically and it being environmentally 'warmer'
Even with extra hydration the cardiac drift will raise the HR upwards until you are pedaling away going literally and metaphorically 'nowhere'?

To combat this do you have to do longer intervals at a higher HR than you would use on an outdoor training ride?
Your 85% mhr will have 2 versions - one for indoors , other for outdoors?

John C.

doyler78 wrote:

Here's an example from last Saturday's 2x20 for anyone not sure what the OP is talking about. Power consistent to within a few watts throughout both intervals. Warmup could have done with being at least 5 mins longer but I didn't have time for that. My power didn't suffer so was very happy with the session inspite of the heat and scaled back warmup.

As I only have a hrt monitor and rollers am I better off doing my sessions at a given speed rather than heart rate. I know what speed is indicated at the start of a session and what it is at the finish. I have previously done 5 at LTHR then 2 at 75% hrm repeated 4 times as per last month C+. or just 2X 20 at LTHR.

Sorry if I've hijacked this thread.

Bronzie

Once you've sussed out what speed (on rollers or turbo) puts you into the "correct zone" for whatever training you are trying to achieve, then yes, I think using speed* rather than target heart rate is the best measure for the intensity of you indoor training.

* - presumes that the resistance of your turbo or rollers is fairly consistent from session to session (which is not always the case)