Why would you need to limit your dietary cholesterol income (intake?) ?
And you're prolly referring to the article where Mark recommended 60-100 extra carbs, above normal daily intake, for each hour of "intense" endurance work. Primal Compromises for Athletes | Mark's Daily Apple
You're pushing yourself that hard 3 times a week? Whether or not you are, the whole point is to figure out how much works for you. What Mark wrote is a recommendation, a starting point, based on his experience, but you have to figure out what works best for your body from there. Maybe you only need 60g of carbs normally. Then a hard 2 hour run might only require 120g more possibly. Maybe less, maybe more. Experiment and eat what feels right to you.
Also, you may want to look at carb calorie intake. The human body can utilize a maximum 600 calories of glucose per day, plus around another 100 carb calories per hour of intense training. The Perfect Health Diet explains explains this thoroughly here: Protein for Athletes | Perfect Health Diet