Hold your hand slightly open then start moving your fingers back and forth as fqast as you can but not all at once, Two groups of two fingers thou is ok. Do this untill your hands and fingers feel warm. Stop, open and close hand a few times then repeat with other hand. Do two sets for each hand. What your wanting to excercise is what are called fast twitch muscles, there not strength muscles as such. Do this hand excercise with this variation as well: As before but cascading fingers kinda in a follow along manner. pinky, next to it, middle finger, one after the other. But continue the back and forth for each. Youcan kinda shake your hand a little while doing these excercises. But focus is one rapid continued fingers going back and forth.
Variation 3: Like the two above excercises but this time doing successsive finger curls one after the other or in groups of two. Again, do excercise untill hand and fingers are nicely warm. Then stop, open and close hand a few times at medium slow speed and repeat excercise with other hand.
BTW. For bass playing specifically, put your fretting hand facing in fretting position while you do these excercises every other time. If you play with a pick, modify the excercise every other time with doing fast continous strumming motions from various angles. With hand anf fingers configured as though with thumb and two fingers pick grip. But dont hold a pick while your doing this. Cause your wanting to develope that fast twtich muscle thing for each finger so that either finger can kick off the upper push and pull down. Its like this. With finger style most can play faster cause they double strike string with alternate fingers. These alternate fingers can also double kick the pick and aid in that faster back and forth that can happen when little changes to angles occurs with the finger motion. Yes at one time my goal was to be able to play along with John Mclaughlins guitar solos on bass. I pretty much outgrew that, but still, the excercise does benefit finger dexterity, precision, speed, and nimbleness. And can help prevent finger and hand cramps to btw. Lol. But anyway these excercises originated for guitar players of course, but makes more then enough sense to apply em to bass. O and last but not least. When your fngers are tiring a bit, slightly varying the angle can help you continue on and catch your second wind fretting and picking or finger plucking. striking wise.
