Runner’s World; Instagram @lissylifts4, @leighannhealey, @alieurquhart; TikTok @sydgrows As joyful and fun as running can be, it’s also, by nature, repetitive. It’s why we join run clubs, or listen to music, or change up our running routes . And recently, runners have been incorporating a new way to add some fun and variety to their runs with a little game called the “alphabet challenge.” There are two versions of the challenge. The first, also popular for hiking and walking, involves greeting the people you pass by—but there's an alphabetical twist. Starting with the letter 'A' and going all the way to 'Z,' each greeting has to start with a given letter of the alphabet, in alphabetical order.…