Anaerobic base benefit going down over time for the same exercice

The body adapts to your training, so if you do the same exercise, you would usually expect diminishing returns. What is your load focus saying? 

ovekvam said:

The body adapts to your training, so if you do the same exercise, you would usually expect diminishing returns.

Yes this is also my expectation and was just wondering if this is indeed what Garmin effectively is capturing (in which case this is of course totally fine) or if there could be other, more subtle reasons.

See below for my load focus.

Looks like you could benefit from more polarised training, to get more low aerobic and anaerobic.

ovekvamok so as a quick follow up.

Today I did another row, the same as yesterday but this time, I sped up a bit and did it with a HR target of 141 which is right above the Zone 3 threshold. So no longer zone 2.

Sure enough I got a better aerobic score, 4.0 to be precise, but it was a Tempo benefit. Not Base. And my aerobic base deficit, of course increased further. See below screenshot.

I'm not sure what else I can do to improve my aerobic base. It seems I need to stay in zone 2, but row for hours and hours.

I currently happen to have the opposite situation. I have correct amount of anaerobic exercise, not enough high aerobic, and too much low aerobic. But that is how I want it to be. Some hard intervals, and otherwise quite laidback exercise. If you want more low aerobic, row slower.

Yes rowing slower is not an issue, I can stay in zone 2 forever without hurting anything. Problem is the amount it takes. Like yesterday, I got marginal base benefit (3.0) and had to row and hour and a half to get this.

Would you mind sharing what kind of aerobic base training you are doing (in a given session) to get to a decent benefit ?

At this point I find it much much easier to get some high aerobic benefit, than low aerobic benefit ! Strangely !

The thing is that the low aerobic exercise are not giving much training benefit. But they allow you to recover and build stamina for those hard interval exercises that will give you a high training benefit. If you exercise many times a week, it should not be a goal to get high benefit from every activity. 

Ok I understand what you're saying.
This makes sense.

Thank you !

If you ask a top level endurance athlete what most normal people do wrong about their training, they will tell you that the easy workouts are not easy enough, and that the hard workouts are not hard enough.