PUTTING A HIGH-INTENSITY-INTERVAL TRAINING(HIIT) routine into practice is typically simple, even if the exercise segments themselves are often challenging.

Point is, HIIT workouts shouldn’t be complicated—they’re already tough enough. Here’s a intermediate-to-advanced HIIT workout pattern designed by trainer Jim Ryno. It takes only 15 minutes and utilizes the exercise of your choice. Sprinting, jumping rope, tire flips—it’s up to you.

Phase 1: Warmup

Do your chosen cardio at 50% intensity for 3 minutes.

Phase 2: HIIT intervals

Do 30 seconds at max speed, then 30 at half speed. Repeat for 10 cycles.

Phase 3: Cooldown

Do 2 minutes at 50% intensity.

by Joe Wuebben