You up for a serious challenge? Then try this calorie-torching HIIT workout from Equinox [1] trainer Anja Garcia [2]. Challenge yourself even more and take it to the next level by using a set of medium free weights! This workout will leave you breathless and feeling the burn in every muscle. Grab a bottle of water, a towel, and dumbbells if you want them, and get ready to work. Remember to take this at your own pace. You got this.

Credits: On Anna: Richer Poorer top [3], Terez tights [4], and Reebok shoes [5]. On Anja: Nike tights and shoes [6]. On Cynthia: Show Me Your Mumu top [7], Alo Yoga tights [8], and Athletic Propulsion Labs (APL) shoes [9]. Anja's mat: Yoga Design Lab [10]; Anna's and Cynthia's mats: Vagabond Goods Yoga [11]. Cheeky water bottles [12].