Cycling and your heart rate response.

Ever wonder why you can be working out so hard on a bicycle, feeling like you're giving it everything you've got, but your heart rate simply doesn't reflect that? There are a few reasons why this can be happening.

1: Gravity.  Simply put, your heart doesn't have to pump against gravity when you're biking as much as it would if you were running (standing). The bicycle is doing a good job at holding up your body weight, so your body doesn't have to do as much work.

2: The training response.  Unless your legs are trained to cycle, the leg muscles fatigue before your heart rate can get up higher.  It's a classic example of "you're only as strong as your weakest link." 

So, if you're doing an assessment for your heart/cardiovascular health using a bicycle, but you rarely train on one, just know that there will be limitations to that test. 

Here is a picture graph of the workout I describe in the video. 5 minutes elliptical vs. 5 minutes bicycle, repeated 5x.  Even though I was perceiving my effort to be equal during each exercise, my heart rate was able to get up into green and yellow during the elliptical minutes, while it was only in the blue (and green on the last one) for the cycling minutes.