Jillian Michaels
Credit: John Lamparski/WireImage

Not sure whether or it’s OK to bite into that well-deserved Friday slice of pizza? Just do it! Celebrity fitness trainer and reality TV star Jillian Michaels revealed what is really takes to look like a bombshell at the pool or near the beach this summer and the results don’t exactly require the painstaking amount of discipline we expected.

Yes, it all comes down to a healthy balance between nutrition and exercise, but there’s one key Michaels, who admits to not always hitting her full 150 percent potential, makes sure to follow. “Well truthfully, I do try to stay in shape throughout the year. I fluctuate a little bit given my work schedule, to be honest,” she told InStyle Thursday night in L.A. at a photography exhibition. “In truth, I always tell people the same thing: It’s really simple and it should stay really simple.”

So what’s the ultimate bikini-ready secret? “Don’t overeat,” she said. “Use common sense with your food. I don’t mean gluten, I don’t mean carbs, I don’t mean protein. I mean chemicals. Don’t eat chemicals. And get to the gym if you can, four half-hours a week. When you go, keep your heart rate at 85 percent of your maximum heart rate. It’s 220 minus your age, times .85.”

Time to whip out that Fitbit, stat.

—With reporting by Brandi Fowler