MAF 180 confusion - Can't reach MAF heart rate

by Bob Melia
(Thailand)

I am 60 years old and have regularly cycled for 3 years (3-4 times a week), my MAF HR is 120 and I had an infection earlier this year so deducted 5 then it will be 115.
My question is using a heart rate monitor I cant get my heart rate to 105 without working really hard and this is not sustainable for say an hour, if I do intervals or Hiit then I can easily get my heart rate up into the 120's and 130's for a short time.
Is my aerobic system lacking and should I just stick with it and wait to see improvements, working at maybe 90-100 bpm which is easily sustained for any period of exercise.
I use an indoor bike, but also go out riding when weather allows.

Also if I cycle for an hour is the warmup and cooldown counted as part of that or should i add it as I am doing now so workout is 1.5 hrs a day 7 days a week, its only my first day so maybe being a bit quick to ask this question.

Kind regards

Bob

Nicole's reply:
Hi Bob, thanks for your question.

My first thought to your low HR was, lucky you! People who have been practicing sport (usually something other than running) since a young age, often have a well developed aerobic system without even realising it. Maybe this is the case with you.

On the other hand, difficulty getting your HR up into your MAF heart rate zone could also be a sign of fatigue. When your body is fatigued, any effort feels much harder compared to if your body was fully rested. In this case it could be that your body is not fully recovered after you recent infection.

When you calculate your MAF zone, it doesn't mean that you have to implicitly stick within that 10 beat zone. Of course you don't want to go above it during your base building phase but you can go below it without problem. So as you suggested I would go by feel but keeping below your MAF. The warm up and cool down do count towards your total exercise time.

To gauge improvement, make sure to do a MAF test at the start of your base building phase and then do a test each month to see how you are doing. How to perform the MAF test.