I found after mundane hours of practicing scales and theory the thing that single handedly improved my bass playing was my physical condition. I went on a diet and exercised as part of my rehearsal routine.
I know this sounds weird, what does exercise have to do with musical ability. Where being in good health doesn't make you a better musician it does make you able to perform better under high energy/stress situations.
For example my band we have our normal jam session style practice, then we have a full stage show rehearsal, then we run 3 miles as a band. Come back have a jam session. Now exhausted mentally and physically, perform.
What this has done for me as a musician is be able to take any stage at anytime and be comfortable. I'm not up on a stage with lights beating down on me, mentally and physically exhausted, I am in my element. This has helped me prepare for any moment I have went to perform and was already exhausted from lack of sleep, to much stress, or starving cause I forgot to eat.
How did this make me a better bass player? Well it taught me to still be able to use all the hours of scales and theory and use them when I was at my mental and physical done.
You can practice 2,8,10, heck 18 hours a day and none of that means a thing when you can't think because the hot stage lights are beating down on you in a gig in Texas on a summers eve or you play a festival in the day in direct sunlight. So unless you dream of being a studio musician or a music store idol, good health is essential.
In short I feel it is as important to physically be in as good as shape as your ability to play. Also I lost over 70lbs and feel and look better then ever! My bass playing has improved, my ability to have my instrument in a comfortable position (gut pushes bass out and causes you to have your wrist in a unnatural position) is improved, back problems went away and I became more comfortable with my bass.
Does this mean you have to be in good physical health to be a phenomenal bassist? Absolutely not, eat pizza, donuts, dingdongs, and whatever you want, go out on stage and be on the verge of a stroke or look like you fell into the pool. You will still be a great bass player. I'm merely saying good health is important even in music.
So take it as you will. Please anyone overweight that takes offense to this. That is a personal issue just as this is a personal opinion.
