I have never completed one of these pinterest challenges before. I have started many, I even started see resuls when I got to the two-week mark on the abs challenge, but I've never been able to see it through the finish line. One reason is the reps just get ridiculous! There's no reason you should be doing 115 sit ups at once:P The other is while there are rest days, these are periodized at all. The volume of exercise keeps increasing, but the intensity stays the same. You wouldn't keep lifting 5lb weights 100s of times as you get stronger, you'd increase the weight and reduce the reps.
My extra goal this dietbet cycle is to complete one of these challenges, but in my own way. I'm going to periodize the program for myself, and use the chart as guidance and a way to track my progress. I want to have a little extra motivation to work on myself outside of weight loss.