I did STS 2.0 Lower Body 2 this week & there was an exercise toward the end where she did wall squats & had us just hold. I'm thinking an entire workout of that type of exercise would be a tough one!!!!!
I like the idea a lot. Strength is not just about basic concentric move. Isometric exercise is also part of the challenge which can result to gains. I would love an isometric workout mixed with mobility and core.
ETA: Cathe has made us do wall squat in XTRAIN series, Total body triset lower body. The wall squat starts with a dumbbell pick up set followed by an isometric hold to complete a set of reps. I love it.
I did STS 2.0 upper Body 1 today. Few hours I completed it and I am still thinking about Alternating harmer curl combined with an isometric hold. What a pump! I am hoping to see more isometric move added in upcoming workouts.