Lamar has already lost a half step or even a full step, not nearly as quick as earlier.
If he keeps running too much, he will get dinged and even injured a lot and hurt the team. Playing dinged is often much worse than sitting out.
Running QBs get dinged and sometimes keep playing (Trubisky, Mayfield both had injured non throwing shoulders that lingered a few yrs --- non throwing shoulders in harnesses hinder the QBs ((Mayfield did not run but scrambled way way too often and got smashed)). Wentz ran too much too, was a trainwreck after a few years.
There is s long list of QBs that ran too much in against the freak HGH weight lifting mutant defensive players in the NFL and tapered off production wise after while.
5 yrs, 17 regular season games = 85 games.
I would go under 57, games that he starts and finishes, for 5 large.