Heart Rate = Exercise Bike Difficulty Settings?

DetroitHustlesHarder69

Having trouble figuring this out. My low intensity HR for cardio is 126 and high intensity is 163. I usually try and maintain the former (126) on my exercise bike. Now here's my question... MFP only has categories for logging this labeled as "light effort" and "moderate effort". Now, if I maintain 126 during the majority of my recorded workout... it doesn't seem like "light effort" to me, but I don't want to give myself more calories than I'm actually earning... so I've been recording it as light effort regardless of how wiped I am at the end of the 30-40 minute session. What would you consider a HR of 126 to be, on the "MFP scale?" for exercise bikes? Just trying to be as accurate as possible...