PopsugarFitnessWorkouts20-Minute Outdoor HIIT Running WorkoutThis 20-Minute Outdoor HIIT Running Workout Is the Ultimate Test of Your Speed and Endurance November 1, 2020 by Maggie Ryan View On One Page Photo 3 of 6 ADVERTISEMENT () Start Slideshow Share This LinkCopy ← Use Arrow Keys → 3 Cooldown Exercise 1: Standing Hamstring Stretch Standing on your right leg, step your left leg forward with your toes flexed.Reach your left hand to your toes, pushing your hips back and keeping your back flat. You should feel a gentle stretch in the back of your thigh.Hold this position for 30 seconds.Place your left foot next to your right as you return to standing upright.Switch sides, stepping your right leg forward to stretch your right hamstring. Hold for 30 seconds.PreviousNext Start Slideshow WorkoutsRunningCardio WorkoutsHIIT WorkoutsNo-Equipment Cardio WorkoutsIntermediate Workouts20-Minute Workouts