I am currently in my first cycle doing the 15,10,5 HST. I have completed day 4 of the 2 week 15's. Something happened yesterday while doing lat pull downs that hasn't happened in any of my other exercises so far with HST. My first set I was able to complete the exercise with 15 reps. After about 90 second rest I started the second set but was only able to complete 12 reps do to muscle failure. Moving forward should I move to only doing 1 set of 15 or should I attempt a second set stop before failure say 11 reps or so,..or even add a 3rd set to finish what wasn't completed, so in this example the third set would only be 4 reps. So that when all is said and done I have completed 30 reps but without going to failure on any reps..thanks in advance for the feedback