I don’t disagree, but conversely, by training specifically for the paces you want to run at, you’re getting the body accustomed to working at that pace. Not necessarily cardiovascularly, or even on an RPE basis, but surely from a muscular movement pattern basis?
When I started my training block after Nice, I initially did some longer weekend runs of 20k+ generally steady, but then they started to incorporate MP work. Initially 25k with the final 5k at MP, then 25k with the final 8k at MP, etc.
Yes, initially those MP efforts felt hard. And you begin to question how you’re ever going to run a full marathon at that pace, but over time the body just seems to become more accustomed. To the extent my main long run culminated with 10k steady into 22k at MP into 6k steady. That 22k went by easily, and I actually got faster and faster (starting at sub3 pace, and ending at sub2:50 pace). For me, that has come from the progressive development in the time, volume and frequency spent at MP, with a lot of easy recovery running mixed in.
I’d finish by saying that by running at target race pace, it also gives me some confidence in what lies ahead. All of this in conjecture at this stage however. Ultimately we’ll have to see what transpires in the race itself! That said, it’s worked well previously with HM’s and HIM’s