Victoria Beckham treated fans to a topless video of her husband David on Tuesday to show off his "impressive" core strength.The fashion designer and David were taking part in a virtual workout with their trainer Bobby Rich when Victoria couldn't resist boasting about her husband's fit physique.MORE: Victoria Beckham's meticulously organised pantry will blow your mindPosting two clips to her Instagram Story, the mum-of-four filmed David as he launched himself into a handstand against a wall in