Thanks for taking the time to feedback each of you.
My site is 'new' so I am simply trying to glance ahead and set-up in a fashion that accommodates good SEO practices and future (possible) expansion e.g. additional course topic areas to avoid site wide rewrites/redirects.
From what I gather there isn't much between the two approaches. So I will move forward with: www.site.com/training-courses/business-analysis (so that in future '/project-management' and other areas can be accommodated simply).
This is based on the assumption that the folder/sub-folder structure count as keywords, and not solely the page slug? I also hear from your responses that content is king, and I should not rely on the URL to be the main contributor.
Interestingly, for me, when setting up my first Moz campaign today the word 'course' was not suggested, with other non-critical words that feature far less often being suggested instead.
Again - thanks for your insight, appreciated.