This last cycle I only did 2 days of 15's, and so far, (starting 5's), I seem to be fine. My biggest problem with HST, and with training in general, is consistency. I've never been able to do more than two cycles back to back without something interrupting my training. Either illness, injury, exhaustion from work, or just life in general has stopped too many of my cycles before I even get to the 5's, then I have to SD and start over again. Because of this, I've decided if I'm only going to be able to get a few weeks of training in, I better do more of it in the heavier range than the lighter range. Others may be in a similar situation so I thought I'd throw this out there.