If you're used to doing high intensity circuit training, kettlebell exercises can be a great addition for getting your heart rate up and burning more calories. (verywellfit.com)
High intensity circuit training versus large complex barbell movements. (lawyerist.com)
PM: Given my restless night, I wasn't feeling up to any sort of workout, but managed to get myself moving for a medium intensity circuit workout. (squashonsquash.com)