Laurie Scher of Oswego knows something about racing up and down hills, plowing through mud and crawling under netting while carrying a 25-pound bag on her back. “I won this women’s division last year.

Rucking, which is simply walking with a weighted backpack, is a great way to combine strength training and cardio without setting foot inside a gym. By Hilary Achauer For this story, the author rucked ...