The exercise classes like zumba and yoga and boxercise will make you sweat and deafen you with the loud music and screaming (interchangeable) instructors, but they lack a very simple requirement for a good anchor. You do those things to lose weight (or in the case of the boys, to gain weight) and you don't do them for long.The reason gyms offer 12 types of yoga is that movement for exercise (medicine) gets boring.You switch classes and instructors and times to keep the interest up and when you finally realize you're supposed to weigh 190 and not 170 you quit. It's not a class, it's a life-long fixture, it's part of you, not something you do for any reason at all.
They may switch to a less vigorous practice as they get older but they will keep moving those joints as long as they can.
Budo isn't for losing weight, it isn't for medicine (exercise done to make you healthy but so boring that you have to have televisions and loud music to get you through it) and it isn't even for self defence (that's a short class not a life-long practice).
Budo is something that you do to anchor your life in time, in mental space and in history as a part of a centuries-long tradition of care from teacher to student.
I came back from the west after a week of seminars and even after the first class here I woke up groggy and stumbling. I was ten years or more in university (OK there was a long transition/overlap period from classes to working there) and through most of that time I practiced martial arts as much for the structure they gave my week as for their skills.
That doesn't negate their use to anyone, especially to university or college students who have a staggered work hours.
I realized that I could use my training times as an anchor to keep me on track throughout the week.
This was so valuable that I switched courses and would have switched majors to avoid losing those fixed points in my life.
Without them I would have been much more prone to missing the other classes. I was recently told that work uncertainties and issues at home had reduced one student's practice hours with a resulting jump in stress levels.
This isn't the first time I've heard that, and in my own case I don't know if I would have made it out of my 20s without the meditation provided by a vigorous class.
It's easy to concentrate on something other than your personal problems when you have wood coming at your head, or when you're upside down above the floor.
Sure, other things provide distractions when you're a student.