3-5mi or 45min run (or jog/walk)

go for distance OR time

Distance: start easy, decrease each mile by 15-30sec for 3-5miles. Last mile should be 'hard' mile pace.

Time: just follow along interval timer for 21min out and 21min back. Cut short as needed.

(entire workout can be done on treadmill or cardio machine)

download timer >> https://www.intervaltimer.com/shared/W2PiaFPx3pN2aImTQROU-4.11-Run-:-Stepping-Stone