Chances are you have slacked. I think, the number one reason for this might be you have forgotten the resolution. The thought has slipped.
I have seen in my own experience, sometimes we are not following the resolutions not because we don't want to but simply because they conceal themselves and our daily fires have taken control.
Most of our resolutions are essential things but not necessarily urgent. So when urgent work and class assignments come, we ignore the necessary.
Exercise to stay healthy is essential but colleague asking to do some of his work is urgent. And just like a crying cat gets the milk, the urgent task get preference over the essential.
So how to avoid it? Simple.
Keep reminders of your essential task and do the essential tasks first thing in the morning.
That's what I am going to follow. Do you have any other tip, share in the comments.