A very common challenge people face in the quest for fitness is sticking with it, also known as being consistent. It's all to easy to set lofty goals, fail to meet them, and then give up. But it's also not helpful.
One option is to accept that "failures" are just steps on the road to success. In her book "Mindset: The New Psychology of Success", author Carolyn Dweck discusses a "fixed" mindset versus a "growth" mindset. People with the former tend to believe they have a fixed ability in life and trying to do more will lead to failure. People with the "growth" mindset believe they can do new things and that trying-and-failing is the natural path toward improving. (More on all this in a future post.)
One approach is to accept failures as being part of the process: no big deal. Another approach is to try to prevent failures from occurring to build momentum and confidence. So if you have trouble sticking with a fitness routine, read on.