Hiking: Conditioning plan for Boy Scouts Merit Badge 20-miler

This summer I have been doing a bunch of hiking both locally in Philadelphia's Wissahickon Gorge as well as in the nearby Appalachian Mountains and Piedmont. Most of my hikes have been fairly intense - meaning they were usually greater than 7 miles and included some moderate elevation change (1,000+ feet) - but I haven't been exactly conditioning for my first "Boy Scouts Hiking Merit Badge" qualifying 20-miler, which has been a goal of mine for about two years now. Now that I've finally become accustomed to East Coast high-humidity hiking once again, though, it's time to get at it!

Recent conditioning hike, Lover's Leap Trail, Wissahickon Gorge

So, without further ado, here is my conditioning plan for preparing to do my first 20-miler.

1. Attack the core. When I first started hiking two years ago I had a core of steel. I had been focusing on my core for more than a year before, doing medicine ball exercises five days per week and planking every chance I got. These excellent habits have waned greatly over the past year, so step one is to get back into near-daily core work. I will return to doing my former medball workout every day except Tuesdays.
2. Hike with a mission. I am able to get to the Wissahickon Gorge to hike on Mondays, Wednesdays and Fridays. Normally I do about five miles each time I go, but now that I'm going to be focusing on conditioning or a 20 miler I've got to amp it up. That being said, I will begin hiking a minimum of eight fast miles at each outing. This means I'll hike with no significant rests for contemplation, picture taking or anything hippy dippy at all. I'm going to book it through those woods!
3. Hike for fun. On Saturdays, I have been in the habit of hiking with friends. This will be my opportunity to slow it down a bit and just enjoy being outdoors for the sake of it. I'm still going to hike fairly quickly, but I'll take time to stop and smell the Hemlock.
4. Hit the gym. After one full month of adhering to the first three steps outlined above, I will add strength training at the gym. I really miss lifting weights, but I know I don't want to bite off more than I can chew right off the bat. Besides, if I do too straight away I'm prone to injure myself, and that would be entirely counterproductive.

Hiking the north slope of Philadelphia's Wissahickon Gorge

Well, there it is. My conditioning plan for completing my first "Boy Scouts Hiking Merit Badge" qualifying 20-miler is fairly intense, but it is totally do-able. I just need to be focused on my goal and intentional about creating the habits over the next month that will prepare me to handle hiking 20 miles in one day between sun up and sun down.