The reason why new years resolution fails is because people went from doing nothing productive (aside from the work or school that they are forced to go to), feel bad about it, and go on pushing themselves completely to the point which they cannot maintain.

The problem is after few weeks, this firepower runs out. BECAUSE YOU BURNED OUT.

Life does not work well when you keep pushing completely to the limit 24/7. When you do push yourself, you need to balance it out with rest, for the body and the mind. This is especially the case for people who didn't build up the habit to be productive. So from not having the habit to going balls to the wall only means that soon you will halt.

Why do little bit everyday?

Think of it like a jog, you will reach half a marathon distance much faster if you jog slowly. If you tried to sprint, you will not be able to reach the finish line as quickly.

Doing little bit is easier to do everyday.

The key is to work hard and NOT burn out. Having a workout routine where you have to go to the gym far too many times a week, while you have jobs, and family responsibility may not be best for you. You may start to burn out. It might be more appropriate to do a workout which lets you go to the gym for not too many times, allows you to recover better.

Working towards your goals little bit every day for months and years will grant greater success than working hard for few weeks.

Doing little bit everyday helps build capacity to push yourself in the nearer future.

If you keep doing little bit everyday, you can actually maintain this for a long time. Doing this for a long time will make you get used to this, hence in the future, it can help you push yourself even harder. Then if you DO push hard, you are less likely to burn out from it.

We all have been told to push push push, and yes pushing is important, but the value of consistency is the most important characteristic that is required to be successful and I have learned this the hard way.