“ There are a few theories behind the origin of on the wagon, but the idiom likely comes from the early 20th-century American expression on the water-wagon, which meant one was drinking water instead of alcohol. Whatever its origins, on the wagon apparently predates off the wagon.
On the wagon and off the wagon are sometimes used in reference to other addictions or compulsions—for example, they’re increasingly used in writing concerned with diet—but they originally referred to alcoholism.”
From https://grammarist.com/usage/on-the-wagon-off-the-wagon/
This time of year, people talk about being on the wagon or off the wagon. We think that since people get together more in the colder months, any deviation from a scheduled, carefully calculated macro-planned meal will mean that all progress will be lost. If we eat that slice of Aunt Mary’s sweet potato pie, our whole way of eating will fall apart. We call that falling off the wagon.
Here’s the thing: you don’t need a wagon. It’s just in your head. Unless you are a professional athlete, having a day to enjoy family and friends is not going to do your training in. And guess what? Even if you are training for competition, you can still have a day to enjoy yourself.
Stop putting so much pressure on yourself to eat perfectly and to train perfectly. Life is about experience and enjoying time with love ones. If you have a good practice of eating nutrient dense foods on a daily basis, you will likely survive a day with some foods that are out of the norm for you. For more information about enjoying holiday dinners without constant stress over food, check out the Intuitive Eater’s Holiday Bill of Rights.
Remember this: Strength and skill are more evergreen that we often recognize and acknowledge. So continue in the things you have learned with your training and nutrition. But enjoy yourself too. You can find that balance if you don’t overthink it.