i and naturally very lean 53kg at 170cm, and do not need to do cardio to lose any fat, however i like to powerwalk on the incline for 20mins 3 times a week. should i be doing this? Is this helping me to tone the lower body? I like cardio after a legs work out to rid the lactic acid. I look cut now and want to add better definition, but will this amount of cardio actually make it even harder for me to add the muscle? am confusing! My diet is very good, high enough in good carbs and protein?