Miley Cyrus is "back" on her "bullsh-t" and busting out impressive treadmill action with one clothing item missing. The 28-year-old singing superstar today updated her Instagram revealing her pre-concert workout routine, with the light-hearted video seeing the "Midnight Sky" singer burning calories, getting her heart-rate up, and managing to do it just fine without the one apparel item most people need to run. Miley was all smiles and the lady in red from her home gym – check out the action below.