When on low-carb (100-150 g) for me, i weight 210, i dont like to do HIIT cuz i have no fuel...so i do long duration (30-45) min of high resistance on an elliptical or walk on a treadmill with the incline as high as it goes, with a speed of about 3 MPH. this always works well for me. when i do HIIT ill usually do it first thing in the morning, even though its hard as hell...i feel good when im done. after i lift i always do easy cardio, but im also an endomorph :head: that might have something to do with it, im not sure