Strength - Allows minimalist shoes to become Olympic Lifters
Endurance- allows augmentation to your shoes to be capable for a multitude of exercises

These things are like instant MAGIC! with multiple ankle injuries my ankles are pretty stiff but I actively am fixing that issue. in the meantime these allow me to hit the heavy % lifts that I know my strength can handle. They've made DEEP Squat movements actually fun! The combo set is the way to go, I use the soft ones for lighter weight metcons that may have pistols or air squats or box jumps or running in them, I use the middle ones for heavier metcons that may also have any of those same.movemenys and I use the stiff ones for strength work. I'd like to add that these are so comfortable I've forgotten they're in there multiple times and gone running even in the stiff ones. I even did murph this year in the soft ones!

AS an older athlete with severe ankle osteoarthritis, these lifts give me the "lift" ,-) I need to get my squats below parallel.