It's often been said that judo, football and other sports teach discipline. At the very elite levels - repeatedly winning major international competitions - I believe that is true because the competition is so tightly bunched together at the top that if you don't have discipline you just don't win. At every level below that, sports may teach discipline and it may not. I think people often misunderstand what discipline means. It doesn't just mean not lazy.
Lazy is defined as "disinclined to activity or exertion" (thank you Merriam-Webster dictionary). Many athletes who get up in the morning and run, do push-ups, lift weights and engage in other strenuous activities are certainly not lazy.
Definitions of discipline include:
control gained by enforcing obedience or order
I would suggest that discipline means forcing yourself to do the things that you SHOULD do. So, if I should be sitting at my desk writing a computer program so that I can get paid and pay my bills but I am instead out running eight miles to the Marina pier and back to the Santa Monica pier, then I am not lazy but I am undisciplined.
A major flaw I see in training of many athletes is they fool themselves into believing they are disciplined when they are really just not lazy. They may train for hours on standing technique when what they really need to work on is their matwork. When they lose, they lament (yes, I did just use the word "lament" in a sports blog. Deal with it.)
"I don't know what to do. I can't train any harder! I train hours every day!"
I've heard this so many times and it is usually a lack of discipline. The player who needs to work on speed of attack in randori is instead running and lifting several hours a week. The person who needs to be more aggressive in randori is doing hundreds of throws every week. The person whose standing technique is pathetic somehow gets to practice too late to do standing randori but does matwork and then stays late "to make up" and does extra rounds of randori.
I see this exact pattern in business as well, people who make lovely brochures instead of sales calls on clients, who go to meetings instead of write code.
Don't confuse activity with progress.
That moral character bit - be honest with yourself. Ask yourself if the activities you're spending the time on are REALLY what will help you win more, or are they just the things you most want to do? Are you using that activity to avoid things you know damn well you should be doing instead?
Not being lazy is good.
Being disciplined is better.