Two-time Olympia Figure Champion (2010, 2012), Erin Stern still looks incredible as she passes down her hard-earned warrior wisdom as relates to staying lean while building muscle. And, in a recent post to her 365k+ Instagram followers, the popular personal trainer broke down the basics of High-intensity Interval Training for those that want to get shredded but don’t want to pick-up a strain. Here’s what you need to know.

“Try adding HIIT to your current routine to help with staying lean and even with building muscle!” suggests the legendary competitor from Tampa, FL. “Rather than hitting the track and sprinting, choose a mode that’s easier to recover from with much less chance of injury.” For bodybuilders and figure competitors, an injury can spell the premature end of their season, so the idea of investing a lot of time in cardio while sacrificing time with the weights seems counter intuitive, but Stern explains that it’s all about short burst. One of Erin Stern’s HIIT tips include that you opt for one of the following exercises, and each can be completed in the gym rather than on the field:

  • Assault bike
  • Spin bike
  • Rower
  • Stairs
  • Hills
  • Pool sprints
  • Elliptical
  • Jump rope
  • Battle ropes

Erin Stern’s HIIT Tips for Building Your Own Program

“Easily build a program by starting with 1-2 sets once per week at 10-20 seconds (with one of the above exercises),” says Stern. “Make sure you get your heart rate up to 80% of max or 0.8 x (220 – age). Take full recovery between sets. Each week, add 1-2 seconds to your set(s). Add an additional set when you feel ready. The HIIT range is anywhere between 7-30 seconds all out, so there is plenty of room for programming.”

You could even adopt a Tabata style approach by blasting through 20 seconds of one of these high intensity exercises followed by a 10 second rest, before repeating. You must

make sure not to take too much rest between sets (ideally don’t rest for longer than you work), as studies show the key to HIIT’s success is in keeping the heart rate up.

“Generally speaking, you’ll do more sets if you’re doing less time, and less sets if your set is longer,” explains Stern. “So, you may get up to 4-5 rounds of 30 seconds… or 8-10 rounds of 10-15 seconds.” The ability to schedule your own HIIT program means that you can fit it around your weight sessions without compromising on bodybuilding or weight loss.

For more great tips, follow Erin Stern on Instagram