We’ve all had days where we felt extremely motivated to get something done and others where we find every excuse in the book not to.
When starting something new, such as a martial art, it’s common to feel excited and eager — so much so, that you must force yourself to take days off from training. Over time, however, you may begin to have days where you don’t want to train but know you should. In this dynamic interplay lies discipline versus motivation.
Yin-yang
Motivation is a relatively easy thing to obtain, as we’ve all experienced at one point or another in our lives. It can come from a motivational speech, watching somebody else achieve something great, or even a conversation with a person you look up too.
Motivation can seem similar to a drug: fast acting and it makes you feel a certain type of way, but it doesn’t last forever. Over time, you can become tolerant to the activity you’re doing and require more motivation until you’ve essentially become desensitized.
This is why breaks are necessary occasionally to help reset this loop, but that is a topic for another day.
[Slumps: Where they Come From, How to Beat Them]

Discipline on the other hand, is doing something despite your inhibitions or circumstances.
When you have discipline, you can separate yourself from your feelings. There are days when you may not feel like training, but you know you’re being lazy. The part of you that holds yourself to a standard and forces you to go anyway is discipline.
Unlike motivation, discipline acts like a muscle. It needs constant training and requires effort to grow. You will likely not have a lot of discipline early on in life, particularly when things are hard. The more that you train yourself to push through feelings and look at the big picture, however, the more your discipline will grow.
Most importantly, discipline is not simply suffering; it’s choosing to sacrifice comfort today for reward tomorrow. The greater the discipline you demonstrate on the front end, the greater the reward you will have on the back end.

How it applies to martial arts
When you’re a white belt in Brazilian Jiu Jitsu, your motivation tank will be full — so full that it will almost overflow. You would train 8 days a week if you could because of how much you love this newfound hobby you’ve stumbled upon.
This is fantastic. Hold on to that as long as you can. Much like anything else, after a period of time you may experience injury, fatigue, burnout, stress, or other life obligations that inhibit your motivation. This is normal, do not beat yourself up over it. This is however where you must begin to exercise your discipline.
Be calculated; do not injure yourself further or ruin relationships to continue training, but do be honest with yourself about your excuses.
If you choose to miss training, ask yourself, “Would my training partners consider this legitimate?” If the answer is no, you’re likely making excuses for yourself and lacking discipline.
Things like “I’m tired” or “I’m stressed” are common excuses but should not get in the way of training. Ironically, these excuses are often resolved by training.

You will have days where motivation runs high and you show up easily. That’s wonderful — capitalize on it and ride the easy wave into training. For those days where you find yourself down in dumps or outright dreading training, fall back on the discipline you’ve built.
Remember that you get to train, you don’t have to. There are many individuals out there who wish they had the time, resources, and physical ability to train but can’t. Don’t squander your opportunities. You never know what may happen in life.
Lastly, remember that training martial arts is intended to be a lifelong journey. There’s a reason why so few individuals obtain a black belt in practices like Brazilian Jiu Jitsu — it’s hard!
Take things one step at a time, remove the words “quit” and “doubt” from your vocabulary, and enjoy the process. Training martial arts is one of the most unique and rewarding ventures in life. Be grateful when you find yourself fortunate enough to participate and ride the wave until no longer can.