Strength Training is an all-encompassing activity. While yes, we do use our muscles to pick up the heavy things, we also rely heavily on our CNS or our Central Nervous System.


What is the Central Nervous System?


The nervous system is comprised of two basic systems: the central and peripheral nervous systems. The Central Nervous System (CNS) groups together the brain and the spinal cord, so if someone were to refer to the CNS, they are directly referring to either the brain or the spinal cord. Conversely, the peripheral nervous system (PNS) is the rest of the nervous system that lies outside of the brain and the spinal cord. This can mean the nerves that connect your CNS to your muscles or organs.


What does the CNS do?

The CNS is the modulator, or the control center of the body. It coordinates everything from breathing to eating to walking to digesting. If you’re doing it, your CNS is involved. The CNS also produces and secretes hormones, which is vital to health and longevity. So to say that the CNS is a big deal is certainly an understatement. Without it, we would not be alive.


CNS and Strength Training

Alright, now that all that background is out of the way, time to get to the important question: what does the CNS have to do with strength training?


In short, everything. When a muscle contracts, your CNS is what starts that contraction. Electrical signs are produced in the brain, sent down the spinal cord and out to the nerves that go to the muscle. The electrical signal then fires the motor neurons which excite the muscle fibers and make them contract.


Needless to say, a lot of work by the CNS and PNS goes into muscle contraction. It’s a team effort, and therefore is no surprise that lifting and your CNS go hand-in-hand. In fact, the stress placed on the CNS is directly proportional to the load you are attempting to lift. So the heavier you train, the greater the CNS response, meaning 90% of your 1RM will elicit a greater response from your CNS than 60%.


Training Your CNS

Motor Units

A motor unit is a special unit in the muscle that activates a group of muscle cells. It acts as a messenger unit to transmit the signals from the brain to the muscle fibers to contract. Research has shown that training with loads of 90% or more if your 1RM is the best way to increase the number of motor units activated, as well as trigger a hormonal response from your endocrine system. Meaning as you increase the load you are lifting, your body becomes more effective in lifting that load by recruiting more and more of you muscles to do so. Crazy how we don’t use all of our muscle fibers all the time right? So at 60% you might be using 60% of your fibers, but at 90%, you are using more!


Rate Coding

The next step above motor units is the rate at which your motor units activate. Termed rate coding, this process is extremely important in generating strength! The faster you activate your motor units, the quicker you generate strength (i.e. elxposive power). To train explosiveness, you have to use a combination of heavy lifting and moving lighter weights extremely fast. For instance, 90% of your 1RM or 80% of your 1RM as fast as possible (without sacrifice technique, of course).



Coordination between muscles and nerves is similar to coordination of, let’s say, a snatch. In a neuromuscular sense, coordination refers to the body’s ability to coordinate one muscle contraction appropriately, and to then have several other muscles firing in the right order. Much like the snatch, you can’t put the bar overhead properly until you’ve brought the bar past your knees and into your hip. Yes, you could, in theory, get the bar above your head, but it would look uncoordinated and would not be as efficient or effective as possible. Same goes for neuromuscluar coordination, to be as efficient and effective as possible, nerves must stimulate the right muscles in the right order at the right time.

Similar to other aspects of training your CNS, to increase the coordination of muscles during a lift, you must train over 90% of your 1RM. This will, essentially, force your neuromuscular system to become more coordinated and therefore, stronger overall. 



Synchronization is your ability to activate needed motor units at the precise time for maximal strength and efficiency. Rather than motor units firing at random during a lift, synchronization trains your neuromuscular system to sync up your muscle’s motor units so that they are all firing at the exact time they are needed (not before or after). Synchronization is best trained using 85% of your 1RM or more. 


Due to our lower levels of testosterone, women tend to make strength gains through a higher percentage of neural changes when compared to men. This can be a challenge when we consider the fact that most of the recommendations for training your CNS involve training at 85% of your 1RMs or greater. We can’t be spending the entire year training at those percentages without burning out, injuring ourselves, or putting ourselves at risk or hormonal imbalances through adrenal fatigue. This is why the saying ‘work smarter, not harder’ is so important when it comes to lifting. While yes, we need to actually work hard, but we more importantly need to work smart. Make sure your training cycles include deload weeks, hypertrophy cycles, and strength cycles. We need to train our CNS, but we also need to ensure our bodies and minds stay healthy!

Listen to Empowered by Iron’s podcast episode all about your CNS and strength training.

Check out our 12 Week Powerlifting program and start training your CNS…and getting hella strong!


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