Curious, does riding steeper climbs lead to stronger legs (in terms of actual strength building). For example, consistently riding a 12% climb for training instead of a 6% climb?
I know the angle on the bike would change and recruit muscles slightly differently. The 12% grade is more likely to bring my cadence way down, closer to that Muscle Tension Interval area. But does it help strength wise or is it just a strain on my aerobic system?
Thanks for any thoughts on this.
I don’t believe riding 12% hills will make you better or stronger. There is the strength factor like you are talking about but we complete that during the resistance training phase. Doing it outside of that will just add fatigue to the leg and body muscles. Ideally you train on terrain you will be racing or doing your events on. Mix it up. Do efforts on flats, 5% and 12%. This way you are comfortable with everything. I find those that constantly do intervals on hills struggle to do the same power efforts on the flats.
Thanks for the feedback, Jake.
Would the answer change if I was targeting a PR on a road that is 4 miles @ 11-12% average or would you still encourage to just keep building the engine overall and mixing it up?
I would still mix it up here when you are in the base phase. But when you transition from a base to race phase and do higher intensity intervals I would do most efforts on the climb or a similar one you want to PR on.
4 miles @ 11 - 12%!! 
That is quite the doozy you have there.
I am targeting a few steeper PRs because I am stubborn and stupid.
Mt. Baldy Rd. (4.3 mi @ 8.9%). Overstated the average but there is plenty of 10+%
Deer Creek ( 2.2 mi @ 11.4%)