Garmin Recommended Running Workouts - Heart Rate

6798117 said:

I tested the by changing my heart rate, made no difference to the recommendation. 

You won't see some instantaneous change because there are many parameters included, including patterns of training history.

For the targets (vs the choice of the workout and the selection of its design - ie # and length of intervals), the main parameter is your VO2 Max model.

All the targets are expressed as a % of pace at VO2 max. That % is very close to the corresponding % of the max Heart rate reserve.

This means that if the watch selects let's say 65% of pace at VO2 Max, the watch will look at your training history to find the pace that corresponds to long/very long steady pace runs measured by 65% of max heart rate reserve. It is more complex than this because the watch use a predictive model based on patterns, but this is the simplified version.

So the key thing here is that your heart rate zones or LTHR zones or settings don't impact the targets. Only your training history.

The most important parameter you control that has (unfortunately) the most influence on all this is your HR Max. If the doctor lets you, do a field test. They are brutal tests if you do them right, but they will give you a better estimate. If you don't push yourself during these tests very very hard, you will get a peak HR that is sub-maximal.

The second most important thing you can do is to keep a balanced training program. On top of cost/benefit optimization, a balanced training program will record a range of HR/pace patterns that will help the watch refine its VO2 Max model and training history.

6798117 said:

I've been using the watch for about a week recommendation may be more realistic once it has more data. 

Correct, provided that your HR Max is correct.

Thanks for your detailed response, much appreciated. Will see how I go over the next few weeks. Today's recommendation is 46min at 135bpm or at 6:30min/km.   I'll stick with 135bpm..