I exercise daily 2 times a day most days and even 3 some days. I rack up activity points quickly. Isn't it technically just canceling out my workouts if I eat the points?

This is kind of tricky - and my experience is that you have to play around with the system.

I earn a lot of AP's a week (I went up to 70 last week - stupid triathlon training). If I was eating them back, I wasn't losing - so I switched my tracker to take from the WP's first - it's a little bit more controlled for me - I can eat some back, but when I'm out of the WP's I try not to eat into my AP's.

Not exactly. Think of your daily points your fuel for every day living... think of your activity points as your fuel for the activity. Your body needs it to function. It's up to you if you use them, and it is something you can play around with. If I go on a simple walk, I don't really eat extra points... if do some circuit training, or take a class, I try to drink some protein powder with water (I use 1/2 scoop EAS whey protein I get from Costco, tastes yummy!). On days where I earn a lot of points I make a "Green Monster" smoothie (spinach, frozen banana, another fruit of choice, greek yogurt, chia seeds, peanut butter)... or sometimes just some peanut butter on 1/2 an english muffin. It helps the muscles repair ie. get leaner faster. I think it's more choosing WHAT you eat, than IF you eat. If you eat them all back as sugar or fried foods, then yeah, it negates the purpose.