With 2019 right around the corner, I've been reading about forming successful habits. Many non-academic sources (and Charles Duhigg's popular book The Power of Habit) have advocated for pairing a cue with operant conditioning's positive reinforcement routine-reward method. For example, your alarm clock goes off (cue), you go for a jog (routine), you drink a fruit smoothie right after (reward).
This seems to be a short-term and damaging solution because of the overjustification effect, where external rewards irreversibly decrease intrinsic motivation.
Is there any evidence suggesting that extrinsic rewards can successfully sustain habits in the long-term? To be more specific, could extrinsic rewards be used for several years and still remain equally effective in supporting the desired habit, or would the extrinsic rewards eventually become less effective at reinforcing the desired habit, given how extrinsic rewards eventually decrease the potency of intrinsic motivation?