The main difference, motivation-wise, between the two is that Person A’s sole incentive is his end goal. Realistic or not, he’s pinned all of his efforts on a reward that he can only enjoy once he’s reached the finish line. By contrast, Person B doesn’t even think of the finish line. They’ve focused their effort on a process that continually links their effort with reward (in this case, running and feeling good). This process-driven approach allows them to strengthen their routine into a sustainable habit.
That isn’t to say that looking to Arnie or Jason Statham to kick your ass into gear isn’t helpful. It is. But if motivation is the ignition, habit is the gas pedal that keeps driving you forward. And this is why your New Year’s Resolution motivation probably ran out: you tried to make a cross-country road trip solely powered by your car’s ignition, and not its fuel tank.
To make a successful metaphorical road trip, you need to follow a two-step process:
1. Start the ignition -- i.e. create short-term motivation to get you into the gym.
2. Use that momentum to start creating visible, quantifiable results.