Some days I really like to do a lot of single-side work, and this is a great workout for that! Obviously, working with both sides of our body at once means more power, but isolating one side at a time is a chance to work on asymmetries, weakness, and other issues that may affect our form on one side. In the case of the Bulgarian split squat, we are using weights on each side for balance, but we want to focus on each side as we work it independently, making sure to send the hips back to squat down and keeping our knees from caving in. Let's see some serious intensity in the plank mountain climbers in your HIIT finisher!