An American fitness fanatic will have to tone down her routine after a new workout caused her Achilles tendon to snap, leaving her in agony.
Video shows Tiffany Van Dyke, 41, working out in the living room of her home in Bay City, Texas where she was making a recording of her latest fitness routine.
She was performing repetitions of a knee to chest exercise - lifting a knee up diagonally across her chest while thrusting both arms down at speed. Some call the exercise "high knees".
But part way through the new routine Tiffany hears a loud snap and is forced to stop. She limps backwards in pain.
Managing to hobble to a nearby armchair, Tiffany is unable to it down without being in excruciating pain as her loose tendon begins rolling up her leg.
Luckily, her seven-year-old son Brock was home from school. He comes to the rescue with ice and moral support.
Tiffany said: "I really can't believe I even had this on film. The 'pop' that the Achilles makes is so loud and anyone who had heard it was in shock.
"I literally thought a gunshot had gone off in my house.
"Of course I was in pain and in shock also but the way my little boy Brock came into my rescue was awesome."
Brock took care of his mum until Tiffany's father-in-law arrived to take her to the hospital where she underwent surgery two days later.
But it was another three months before Tiffany, a high school science teacher and online health coach, could start jogging again.
She said: "I had never had any severe injuries in my life, just a few ankle sprains.
"It felt like my leg was on fire. It was the craziest feeling ever. I could actually feel my tendon roll up my leg.
"I was unable to move my foot back and forth and knew immediately that it was my Achilles."
The injury, which occurred in October 2016, also saw part of her calf muscle blown.
Tiffany faced a long road to recovery after her injury but was determined to beat the six-month timescale doctors had given her.
She said: "I had read many posts and articles about the average person rupturing their achilles and many said they never returned to normal.
"I spent five days a week in rehab doing stretches and using a 'wobble board' to build strength back in my leg."
Tiffany was back jogging and doing basic workouts three months later.