When I first started working out, I hated it (maybe you too). Yes, soreness hurts, but as I progressed, I no doubt embraced it. Most of us consider it a signal that we’ve done our job and stimulated plenty of muscle growth. But is that true?
Actually, there are no studies connecting muscle soreness to hypertrophy. But don’t stop reading yet. You will get some good stuff from being a little sore (and you’ll probably even desire it). But first, you need to know what provoke muscle soreness.
It’s believed that the pain is produced by microtrauma in muscle fibers, and it’s mainly triggered by the negative or eccentric stroke of an exercise (like when you lower a bench press, squat or curl rep).
Once your body repairs those microtears, it follows that the muscle should grow stronger; however, that trauma is in the myofibrils, the force-generating actin and myosin strands in the fiber. Those strands grab onto and pull across one another to cause muscular contraction. When you control the negative stroke of a rep, there is friction as those strands drag across each other in an attempt to slow movement speed to prevent injury—and that dragging, it’s believed, is what inflicts the microtrauma.
That’s a simple way to explain it, but you get the idea. So it looks that some growth can happen after muscle soreness is repaired, but it’s in the myofibrils. More and more research is beginning to reveal that those force-generating strands do not help the majority of muscle size; serious mass comes via sarcoplasmic expansion. That’s the “energy fluid” in the fibers that’s filled with glycogen (from carbs), ATP, calcium, noncontractile proteins, etc.
So, if soreness is a signal of only small amounts of muscle growth, why look for it? Well, even small amounts of growth contribute to overall mass. Most of us want every fraction we can rasp up. But the real goal to seek some soreness is to burn more fat.
When the myofibrils are damaged by focusing the eccentric, the body tries to repair them as quickly as possible. That repair process takes energy, a lot of which comes from body fat. The process generally takes many days, so your metabolism is stoked to a higher level for 48 hours or more, helping you get leaner faster (Note: High-intensity interval training, like sprints alternated with slow jogs, damages muscle fibers during the intense intervals, the sprints, which is why HIIT burns more fat in the long run than steady-state cardio where no muscle damage take place).
Do you need heavy negative-only sets to obtain that extra bit of size and metabolic momentum? That’s one way, but negative-accentuated, or X-centric, sets may be a better, safer way.
For an X-centric set, you take somewhat lighter poundage than your 10RM (repetition maximum) and raise the weight in one second and lower it in six. That one-second-positive/six-second-negative cadence does some great things, starting with myofibrillar trauma for some soreness. While you’re dealing with that extra post-workout muscle pain, remember that it can build the myofibrils and that it’s stoking your metabolism for the time of the repair process for more fat burning.
The second big advantage is sarcoplasmic expansion. At seven seconds per rep and eight reps per set, you obtain almost an entire minute of tension time (seven times eight is 56 seconds). A TUT (time under tension) of 50 to 60 seconds is something most bodybuilders never attain, which is a shame because that’s optimal stress for an anabolic cascade and this is the ideal way to train as you age.
If you’re into moderate-poundage, high-fatigue mass building, then the F4X method featured in the Old School New Body method is for you. You can use X-centric as the last set of the sequence. Reduce the weight and do a one-up-six-down cadence. You’ll get sore, build some extra size and—bonus—burn for fat. How great is that?