Bella Hadid Reveals Tiny Waist and Workout Secrets

showed off her tiny waist while clad in a cropped military jacket on the set of a recent mystery fashion shoot.

The 29-year-old IMG Model was rocking a smoky eye and had her honey-blonde locks blown out.

Hadid - who boasts 72.7 million social media followers - also included a gif of herself kneeling on a Pilates reformer at the gym in her newly uploaded, 20-picture Instagram slideshow.

The half-Dutch, half-Palestinian stunner has been gaining her strength back after landing in the hospital last September with symptoms stemming from her 13-year battle with chronic neurological Lyme disease.

Hadid, her mother and her younger brother Anwar Hadid contracted tickborne illness in 2012 and 2013.

'You are relentless and courageous. No child is [supposed] to suffer in their body with an incurable chronic disease,' the 62-year-old alum wrote on September 18.

'I admire your bravery and your willingness to keep fighting for health despite the failing protocols and countless setbacks you have faced. There simply aren't words big enough for the darkness, the pain, and the unknown hell you've lived through since your diagnosis in 2013.

'You didn't really live, you learned how to exist inside the jail of your own paralyzed brain. I am so proud of the fighter that you are. You are not alone, I promise to have your back every step of the way, no matter how long this takes.'

Yolanda continued: 'This disease has brought us to our knees, but we always get back up. We will continue to fight for better days, together. You are a survivor. I love you so much my bada** Warrior.'