Today was cold and rainy. I stayed in, goofed off, and found it hard to do my weight training. But I did it anyway, it just wasn't very "fun."
That's the thing about any big project like this. There are times when it's just not fun, and those are the times when you feel most alone, and giving up doesn't seem so bad. More than any other time this is when you've got to "zen up"
If you've ever tried to keep a meditation practice, you will know that some times sitting is the last thing you want to do, and at the same time it's the best thing you could do. And you just do it. And it's usually the thinking about doing it that is hard, not the actual sitting.
Well, jumpropes, weight training, and egg-white smoothies are the same thing. You just do the thing, and try not to devote too much mental energy to how you don't want to, how it's hard, and how you could be doing something else.