Well you determined and calculated your progression for the cycle, yes?
It's entirely plausible that you under-determined your xRM's and are working an increment or two below your actual xRM's.
Or, as I said, it's worthwhile not to underestimate the impact of properly spaced sets. When working at 80% + of 1RM (5s range), the difference between 1min between sets and 2-3min is pronounced, w/regard to impact on your CNS and DOMS.
I'll also add that 'growing' is dependent upon diet, and increases (or lack of) in size are a terrible judge of sufficiency of volume if you aren't gaining weight throughout your cycle. If that scale isn't increasing, then neither is your volume definitely shouldn't be. And add on to this you get satellite cell activity for up to a week (or even 9 days) after cessation of load stimulus, and you can see that measuring volume according to growth is never a good way to go.
You said you think you might be undertraining w/regard to load/volume. We've covered load; it's highly plausible you're not lifting at the proper loads. Rest periods are also important, as is diet.
Are you having trouble sleeping and can confidently put it on your exercise regime? Anyone doing HST 3x a week is getting a fair dosage of activity, especially if both upper and lower are covered.
Soreness//DOMS are probably the 'last resort' method for arriving at the conclusion that one is undertraining. DOMS is not especially difficult to create (being a sensation of nerves, not muscle), and correlating absence of DOMS with absence of sufficient volume is tenuous, forget about causation. I've done cycles where I've grown without any soreness (single sets), only ever becoming sore due to a bad exercise (flat flyes being horrible; leverage, load, connective tissue etc) or accompanying cardio (yay basketball).
Long story short; if you're worried that your volume isn't enough, look first to increasing load. Secondly, use the scale and a tape measure for what they're intended: to tell you if you're getting bigger or not. Subjectivity is dangerous for measuring progress.
It's entirely plausible that you under-determined your xRM's and are working an increment or two below your actual xRM's.
Or, as I said, it's worthwhile not to underestimate the impact of properly spaced sets. When working at 80% + of 1RM (5s range), the difference between 1min between sets and 2-3min is pronounced, w/regard to impact on your CNS and DOMS.
I'll also add that 'growing' is dependent upon diet, and increases (or lack of) in size are a terrible judge of sufficiency of volume if you aren't gaining weight throughout your cycle. If that scale isn't increasing, then neither is your volume definitely shouldn't be. And add on to this you get satellite cell activity for up to a week (or even 9 days) after cessation of load stimulus, and you can see that measuring volume according to growth is never a good way to go.
You said you think you might be undertraining w/regard to load/volume. We've covered load; it's highly plausible you're not lifting at the proper loads. Rest periods are also important, as is diet.
Are you having trouble sleeping and can confidently put it on your exercise regime? Anyone doing HST 3x a week is getting a fair dosage of activity, especially if both upper and lower are covered.
Soreness//DOMS are probably the 'last resort' method for arriving at the conclusion that one is undertraining. DOMS is not especially difficult to create (being a sensation of nerves, not muscle), and correlating absence of DOMS with absence of sufficient volume is tenuous, forget about causation. I've done cycles where I've grown without any soreness (single sets), only ever becoming sore due to a bad exercise (flat flyes being horrible; leverage, load, connective tissue etc) or accompanying cardio (yay basketball).
Long story short; if you're worried that your volume isn't enough, look first to increasing load. Secondly, use the scale and a tape measure for what they're intended: to tell you if you're getting bigger or not. Subjectivity is dangerous for measuring progress.