About the question of rollers and high intensity intervals, wouldn't you want to do them on rollers to ingrain in your mind the act of holding your line perfectly ? Wouldnt that help build core and stability and make our body used to have that stability and core strength for when you gonna put that same wattage on the track ?
Everyone seems to recommend to get larger rollers (3.5 and plus) but kreitler use the fact that the usa track team was asking for smaller rollers for their training to sell their 2.25 rollers, could there be any reason why smaller rollers are actually useful in training and warmups ?