This particular cardio-core move has become a mainstay in a wide range of modalities, from HIIT to boxing to Pilates. It involves holding a plank while jumping your legs in and out, mimicking the ...

"She's extremely strong and works incredibly hard," Olsen's trainer, Jessica Schatz, told People. "Ashley is disciplined, hard-working, and open to trying anything new." So what does one of her ...