I’ve never read any convincing evidence that doing anaerobic workouts destroys aerobic capacity, rather as stated previously on the thread you can retard your aerobic development by replacing it with too much anaerobic stuff.
A. Anaerobic stuff is, by nature low volume, so you’re not getting a great aerobic stimulus during the workout.
B. Hard repetition type workouts will leave you sore the next day, reducing the volume and quality of that workout as well.
If done properly, some high rep, low rest, upper body lifting will help your body deal with acidosis. Look up the term “lactate shuttle”.
Basically, when your running muscles start to pour lactate into your blood, some of it will circulate to other tissues in the body and be processed. I don’t know about you, but when bid get to the death throes of a race, I’d get funny things happening like my forearms tightening up and my teeth hurting.
Take this next part for what you will, sample size of one.
In grad school, I worked in a gym for about a year. During that time, I started playing around with a super set type circuit where I was able to go from exercise to exercise for about 30 min. At one point, about 3-4!months in, I remember going to the track and doing a workout that normally made me start to tie up in the upper body. During the last couple of reps of the workout, I remember thinking that I was still feeling really good. None of the usual tightness was seeping into my upper body.
I ran a few races during that time and despite actual running training being far inferior to what I had done with my college team, I was able to run within 10 seconds of my 5k PR a couple of times.
These days, I tend to agree with eurodonkey on the John Day “easy strength “ type system. The low volume, high load system is great for stimulating anabolic hormone release without creating soreness that lingers. I’ve done a number of his 8 week cycles and never feel any soreness the next day. You probably don’t need to follow the plan exactly as written to get the benefit that you need as a distance runner. 3-4 days a week would be fine instead of the 5 recommended in the plan. If you don’t do a lot of heavy stuff, start pretty light with it and only increase the load as the workouts begin to feel easy