I believe it is Tim Ferris who said: “It’s better to follow a good program consistently than to follow a perfect program inconsistently.” …or something close to that. Tim, I apologize if I’m misquoting you. The point is, if you are trying to improve yourself, whether it be nutrition, exercise, studying, or any other forms of self-improvement, and you implement an overly strict and ambitious program, you simply aren’t going to follow it on a consistent basis. Which negates the whole point.
Rather, if you establish a good program that isn’t exceedingly ambitious (i.e.: it allows for cheat meals, it doesn’t require an hour of sprints 5x a week), you are much more likely to be consistent. And consistency is the key to success. The idea is to incorporate positive lifestyle changes that become part of your routine. Drastic “fixes” don’t last. HABITS are lasting and effective.
The widely accepted benchmark for developing a new habit is 2 weeks. That is to say, if you can follow a new gym program or sleep schedule for 2 weeks, it is likely to become a daily standard. The new activity is now just a comfortable and expected part of your everyday.
This isn’t to imply that your new habit shouldn’t be challenging. It’s good to challenge yourself. However, don’t start off going 100 miles per hour if you know it isn’t sustainable yet. Start at 60 miles per hour, and work up to 100 once the activity is firmly ingrained in your lifestyle.