You can build more muscle, increase natural growth hormone levels, and utilize lactic acid for energy through a technique called Time Under Tension.

'Time under tension' is no walk in the park and I do not suggest it for anyone that isn't 100% serious about competing or getting results from hard work.  

The skinny on this "workout style" is to reduce rest between sets to ~45 seconds and lifting as heavy as possible to achieve a 3-1-1 tempo for each rep. This is a serious nervous system stimulation which in turn forces the muscle to contract for a harder and longer time.

Arrange your workout to do the following:
  • Choose smaller muscle groups to perform 30 reps, 20 reps, and 15 reps in secession with 45 seconds rest. 
  • Choose bigger muscle groups to do traditional 4X10 and 3X12 sets using the time under tension protocol.
  • Your goal is to lift 80% of your 1RM, keeping your muscle under contraction (eccentric motion) for 40-60 seconds. 
  • Use your reps/sets to hunt for that deep penetrating muscular burn. 
This is NOT 'German Volume Training'. German Volume Training focuses on lower weight with high volume (100 rep exercises @ 60% of 1RM). Time under tension focuses on heavier weight with long muscular contractions (~40 rep exercises @ 80% 1RM). 

The two workout protocols (GVT vs TUT) actually work totally different muscle fibers.

I've been seeing mass gains from this program; however, it's important to note that this type of workout requires time off and a temporary (1-2 weeks) change in program protocol to effectively rest and heal (before starting again).

The time under tension protocol drastically reduces risk of injury. 

As you use the time under tension protocol you'll find that using about 20% less in weight (with triple the time under tension) actually creates about an 80% increased stimulation in the muscle. Less weight usually means less risk of injury - and less weight usually means better exercise form (which obviously decreases risk of injury).

But here's the dealio - after following a time under tension protocol, using less weight with more time, you'll actually get stronger. When you cycle off this program for a couple of weeks and go back to your manly man heavy weight (with short powerful tempos) you'll notice that you can handle heavier weights for longer periods of time (voila!). 

Pro tip - translation: if you can handle heavier weights for longer periods of time, then you can handle even heavier weights for shorter periods of time - hence - you can spend a few weeks (periodization) building strength in the 4-6 rep range (hint hint).

Research shows that the best way to gain muscle strength is by performing 1-6 reps per set; for muscle growth, your ideal rep range is 8-12; and for muscle endurance, 15-30 reps prove most beneficial. The problem is that all these ranges assume that each rep takes about four seconds to complete. If you extrapolated those figures, you’d assume that the best TUT ranges are 4-24 seconds for strength, 32-48 seconds for growth and 60-120 seconds for endurance. However, strength coaches and training experts have tweaked those values based on their own experience.