This is why trainers want you to ‘burn out’ your muscle groups

Struggling to understand the terminology trainers throw down mid-workout feels like an exercise in and of itself. (HIIT? LIIT? EMOM? What?) During a recent treadmill workout, an instructor told me to hop off the machine and “burn my core out” with a round of burpees. Which got me thinking…what does that prompt actually mean?

While a bad case of “burnout” can sideline your from your day job, done correctly it’s a boon to your strength-training regimen. “To ‘burn out a muscle group’ means to train a specific muscle to full fatigue, where even the simplest rep, or movement feels impossible,” says Aaptiv master trainer Ackeem Emmons.

The method fast-tracks fitness goals by improving endurance and muscle tone. “Training breaks down the muscle fibers, nutrition builds them back up, and muscles become stronger. If you burn out a specific muscle group, with proper rest days in between, muscle growth is guaranteed,” says Emmons.

To start incorporating the “burn out” into your next sweat sesh, first consider which group of muscles you want to suffer—rather, to get stronger. Instructions are quite simple: “Perform as many as reps as possible within a short amount of time, with minimal rest, for a certain number of sets,” says Emmons. If like me you’re into running in place lately, you might consider hopping off the treadmill and punishing your hamstrings and quads with a relentless round of weighted squats. But remember to mix it up. To avoid injury, don’t go hard on the same muscle group for two consecutive days.

“One can burn out different muscle groups every day or every other day. [But] mapping out your program, and your current training level is crucial,” says Emmons. If you’re just getting started with regular strength training, you may experience delayed onset muscle soreness (DOMS), muscle fatigue that sets in later than expected after a strenuous workout. Recovery days are just important as active training days. “We are not robots,” says Emmons. “The body does need time to rest and recover. Training hard is cool, but training smart is the ultimate goal.”

Put those newly toned muscles to the test with this intense plank variation. Or this one.