Specific Adaptation to Imposed Demands (or SAID) is a principle from exercise physiology. SAID basically says you get better at what you do—whether you do something intentionally or unintentionally, formally or informally. It also means you get better at the specific thing you do, not something else. There may be positive carryover, or there may be negative carryover, or there may be little-to-no carryover at all to other activities.If you run long distances slowly, your body adapts, making you better at running long distances at that speed. If you sit in an office chair all day, your body adapts to that too, making you better at sitting in office chairs all day (and worse at other things, like running long distances).
SAID also implies that running long distances slowly is not a good way to become better at running short distances quickly, nor lifting heavy weights a few times. There may be some positive carryover to sprinting (but not much), and there may be negative carryover to lifting heavy weights a few times, but primarily if you run long distances you’ll get better at running long distances.
One implication of SAID for personal development generally is that if you want to get better at something, practice that thing—not something else. To get better at soccer, play more soccer. You can of course also break the skills of soccer into small chunks, like passing and cutting and practice those micro skills too. But will lifting heavy weights make you a better soccer player? Probably not, unless being physically bigger would help your game. Lifting may even have negative carryover in adding new muscle skills that compete with the ones you need most, and in the potential for injury to joints, tendons, and ligaments...
If you want to be better at business, reading business books isn’t necessarily the way to prepare—this will make you primarily better at reading business books! Better to open the equivalent of a lemonade stand—something with minimal overhead and thus low risk, but dealing with real customers in a business setting. Better yet would be to do a small version of the Big Thing you want to do....
I could recommend that last bit to a few people at work...but seriously...this bit is key:
SAID also implies that we become what we do—and don’t do. Or as Chogyam Trungpa put it, “the path is the goal.” To become a compassionate person, the path is to practice being compassionate.
The soccer analogy is interesting: sometimes lifting weights does help these sports if the player's limited by his undeveloped muscles/bones. Similarly with compassion. One might need to practice compassion to practice getting along better with others.
This by the way is a nice way of theorizing around Malcom Gladwell's recent book "Outliers," a book-length manifesto based on the old joke: "How do I get to Carnegie Hall?" "Practice!"