This is a progression on 2.0 and 1.0 so be sure to master that before moving on to this more challenging version. Grab a single 10-25 pound dumbbell and fry fat fast with this anytime, anywhere HIIT workout! Shoot to get at least 5-10 reps every 20-second work period. Exceptions include more complex or time-focused drills. where a more time-based focus makes sense. If you're getting 5 reps or less, the bell is too heavy. Once you can do 10+ reps every set, increase the weight by 2.5 to 5 pounds. But don't overthink it. The most important thing is to use max effort without losing form or focus.