Kendall Jenner Is Spotted At The Gym Hours Before 'KUWTK's' Emotional Episode

Kendall Jenner was spotted hitting the gym in NYC hours before an emotional episode of Keeping Up with the Kardashians aired, during which the family had to relive Tristan Thompson cheating on Khloé just days before she gave birth to True. Read on to see pics of the supermodel sweating it out.

Kendall was photographed in a hoodie embellished with friend Jaden Smith's"Syre" album art as she left Gotham Gym in NYC.

The supermodel recently celebrated her 23rd birthday with family and friends. Khloé penned a heartfelt message for her little sister on her b-day.

"Happy birthday my sweet Kenny!" Khloé wrote. "I love you for who you are and couldn't imagine a life without YOU. If anyone knows you like I do, they know how much of an amazing, kind, quirky, loving person you are and how much any one would dream to have you in their life. Some people aren't as lucky as us. Not everyone gets to have a sister and not everyone gets to have a love and bond that all us siblings have with one another. Blessed we are! We all celebrate you today and every day! Let your confidence continue to shine and never be anyone but yourself. You are perfect in every single way. I love you my sweet angel sister!"

Last night was Kendall's chance to be there for Khloe as she relived the painful experience of finding out Tristan was cheating on her when she was pregnant. "You may forgive, but forgetting is not possible," the Good American founder tweeted during the episode.