Find what you are passionate about and start to consume everything you can on that subject. Similarly is there something you just are not that good at or have a perceived weakness in? If so start voraciously absorbing every thing you can on the subject. There are so many ways you can learn. Below are some Iron Exec approved approaches to learning.
Formal Education - This should never be underestimated. The best part about formal education is that much of the searching and collating of the most relevant and important information has been done for you. Most formal education will provide you the "fundamentals" of a topic so that you can then confidently understand the basic principles of a subject. Formal education can be University degrees, online courses, conference attendance, night community classes, or even accreditation weekends.
Just Read! - Certainly one of my favourite things to do, is it yours? Reading is the best and something that everyone should be doing daily. Be it physical books, your Kindle, reading online content you name it you should be reading it. If you find it hard read or find the time try just reading 10 min a day. Everyone can find 10 min. What you'll find is that once you've read through for that 10 min you'll likely keep reading. You will be surprised just how much you can get through if you devote just as little as 10 min's a day. If you are an executive you'll be used to long haul flights. This is probably the best time of all to be reading. You aren't online, your phone can't ring, its just you and all the reading you've brought with you. All those articles, books and reports you collected on the subject you are passionate about are yours for devouring.
Podcasts - This is an awesome learning hack. That time spent commuting on the train or bus. That time your stuck in the morning peak hour in your car. Whack on a podcast and let the learning begin. If you haven't got on to this train yet, buy yourself a ticket and jump on. You only need to look online for any subject you are interested in and I guarantee you there will be a podcast on the subject. I've even heard of some who train themselves to listen to Podcasts at 1.5x or even 2x speeds so that they can consume more podcasts in the same amount of time it takes to listen to one. That is some serious dedication to learning.
For the Iron Exec who loves to lift and get strong both as an athlete and a business person here are some suggestions to get you started:
Strong Medicine
Purposeful Primitive
IronRadio
Antifragile