https://timerist.com/timers/hiit-presets.html
HIIT Timer - Timerist | High Intensity Interval Training Timer, Tabata, 30/30, 4x4 Norwegian
HIIT timer with preset protocols (Tabata, 30/30, 4x4 Norwegian) and custom intervals. Includes prep countdown, cool-down, sets, and motivational phase labels...
high intensityinterval traininghiittimer