ET has your exclusive first look at this week’s all-new episode, which finds Kim on a mission to prove to Kourtney that her ultra-healthy, gluten-free lifestyle isn’t actually benefiting her that much. To prove her point, Kim challenges Kourtney to a “sweat test,” alongside pal Jonathan Cheban. According to Kim, they can collect their own sweat in vials and have it sent off to a lab to be tested for various toxin levels.
“Gluten, with a sweat test?” Kourtney asks, skeptically. “I’ve never heard of it.”
“I’ve never heard of a ‘sweat test,’ and it just sounds gross,” she adds in a confessional. “But, we do some pretty crazy things to get the information we need, especially when it comes to, like, beauty and health. So, I am definitely willing to do Kim’s test to prove that I’m healthier.”
In order to collect enough sweat for the test, Kim, Kourtney and Jonathan head into a sauna -- wearing thick bathrobes -- and slowly let their skin drip into the vials. Watch:
Unfortunately, Kim and Kourtney realize their sweat is likely contaminated by makeup and spray tan, so the ‘sweat tests’ will give them false results. That’s when Kourtney tells Kim and Jonathan they need to do a “real test” at a doctor’s office to find out once and for all who is the healthiest Kardashian.
You’ll have to tune into Keeping Up With the Kardashians on Sunday at 9 p.m. ET on E! to get those results. In the meantime, check out the links and video below for more on the Kardashian fam.