This Total Body interval challenge moves through three continuous effort levels—90%, 70%, and 60%—using fast feet, running, and marching to elevate your heart rate, build cardiovascular endurance, and support VO₂ threshold training.

Each round takes about 5 minutes, so repeat as many times as you want!

Focus: VO₂ Thresholds • Cardiovascular Endurance • Total Body Conditioning
Equipment: Water!