I am not very good at doing specific effort tests, but I have tons of anecdotal data from workouts and racing.
I am 51, and spend most of the year training for Ultra trail races. 80% of my ultra volume is at my endurance, aerobic pace.
in the late summer, I start to incorporate higher intensity work to prepare for skimo race season.
for the past 7 weeks I have been doing what I call my “indoor skimo workout”. I do this workout 2x per week( with 2 full days in between)
1. 10 min warmup
2. 20 mins at 10% incline
3. ME strength: 3×15 single leg box steps, 3×15 single leg lunges.(180 total reps)

I repeat #2 and #3 3 times without stopping. total of 1hr uphill running and 540 total reps of ME strength. takes about 1:45 to finish the workout with short cool down jog.

my question about AeT and AnT is this:
– the max HR I have ever reliably recorded is 175. I only see 175 when I am working extremely hard, and there needs to be a weather factor like extremely hot/humid. or extremely cold.

when I do my indoor skimo workout, by the 2nd run interval, I reach a HR of about 158-160…and I hold that HR for 2 sets of 20 min runs. if my HR goes higher than that, I begin to feel the slow buildup of lactic acid, but if I stay at 160, its comfortably hard but no lactic acid.

if I take out the extreme weather factor, and consider my age, my max HR is prob around 170. my LT run intervals are done at a HR of 160 with no lactic acid build-up. what doesn’t make sense to me is that seems to suggest that my LT threshold is 90% of my max HR. am I thinking about this wrong. or can that be right?

I will add that it takes me a long time to raise my HR to these levels. I seem to need extra time to get to these levels, and if I try to go too hard too soon, I’m panting like a dog and blowing up quickly. if I ease into it over 30-40 mins, I can hold 90% for a long time.
my last trail race of the season was a 6hr timed hill race up/down a ski resort. the climb up took about 1 hr. I was holding a HR of about 155 per 1 hour climb, and I did that 4 times. my PE during the climbs was about 80%( or the max effort I knew I could do 4 times). I did this before introducing the intervals described above.

for skimo, I am trying to raise my LT, but I’m not sure I am thinking about this right. any guidance would be appreciated.