Simon
Some tidbits I picked up while looking for a scientific answer for you:
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">SD is simply a method that allows (not “tricks”) your muscles to continue to grow, using weights that your muscles have seen before.
The method is simple, the science is complicated, the results are significant.
P.S. If you are afraid of using baby weights, check your ego at the door, or use the heaviest weights you can lift from day one an be satisfied with your results, in other words, stop looking for anything better.</div>
and...
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">I have never claimed that a period of Strategic Deconditioning lasting 7-12 days would completely revert your muscles to an "untrained" state. I have spoken frequently of the rapid training effect or repeated bout effect.
Some protection seems to last for a very long time. Still, 7-12 days of complete rest does appear to cause some reversal of the adaptations to training. And from the application, it appears it is sufficient to allow one to start growing again, once gains have stopped with a given weight.
Hopefully through the forum and other articles and interviews people have come to learn that SD is more than just a break from training.
Someone who has trained for an extended period of time using 5s/negs at loads of 85%+ of 1RM would often require upwards of 2 weeks SD to ensure sufficient reversal.
More advanced athletes have successfully extended the HST cycle with 5s and negatives with the addition of drop sets (refer to the drop set thread), but if this is your first time doing HST I suggest you do the regular 6-8 week cycle as outlined on this website.</div>
and to answer you on your state of energy, mind and body:
<div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">HST builds strength sure enough, however, the actual manifestation of that strength depends on the recovery of the CNS (and other neuromuscular factors) from workout to workout. Sometimes a person will gain a little ground on their CNS recovery and their strength output will go up. Those who zigzag are more likely to experience significant "strength" gains mid cycle.
The size gains are dependant on what's happening to the tissue. This of course is dependant on the absolute load as well as the relative condition of the tissue at the time.
So, should you increase, maintain or decrease "volume" as the cycle progresses? It depends! I know how many people hate to hear that...but its true. Here is how you decide. Keep in mind that these factors are to considered “collectively”, meaning each factor must be weighted, not taken as an absolute indicator.
Increase volume if:
You are never sore
You are never tired
You are not growing
Maintain volume if:
You are slightly sore most of the time
You are tired enough to sleep well, but not so tired you lose motivation to train.
You are noticeably “fuller”
Decrease volume if:
You are experiencing over use pain, and strain symptoms in joints and/or muscles.
You are tired and irritable all the time, yet don’t sleep well.
Strength levels are significantly decreasing.</div>
Failing this, you are about ready to SD and start again...considering your nutrition is in check as this could be another reason for your lack of motivation.