The Role of the Central Nervous System in Strength
The Nervous System
The central nervous system (CNS) plays a big part in strength. Your CNS controls the use of skeletal muscles in the body. When you first get started with a strength training program, you will notice strength gains right away. The muscle growth does not occur in the first two weeks, but you have seen some gains already. That is the manifestation of a trained CNS.
The CNS is highly impacted by stress. Many things affect your nervous system.
Your body doesn't differentiate stress by where it comes from. Stress is stress and you have a limited amount of stress your nervous system can handle.
Mind to Muscle
As you begin training, a lot of the movements will be externally loaded for the first time ever, or in a long time. The first adaptation that occurs is that you nervous system will put together which muscles are involved in the movement. You will start to better recruit the muscles. More muscles involved in the exercise will lead to nearly immediate strength gains.
Understanding each exercise you do can really help your mind-muscle connection. Focus on the specific muscles you are trying to engage to better recruit them. You could even have a training partner or coach physically touch the muscles you are working. That helps more than you would think. Sloppy and lazy lifting will not help with training the nervous system.
Exciting your nervous system before your workout begins will have a great impact on the quality of your training session. You should always do this at the end of your warm-up. My favorite ways to excite the nervous system are explosive movements or extensive plyometrics. Some examples include: box jumps, plyometric push-ups, power skips, medicine ball throws, and pogo jumps.
By exciting the nervous system, it tells your body that you are about to perform some intense work. You have told your body to recruit additional motor units (force producers) which translates to more strength and potential output in your training session.
When your nervous system doesn't have time to recover between workouts, you begin to overtrain. During an overtrained state, you will have less productive training sessions and less force output (you will feel weaker). A common misconception to overtraining is that you have to be sore to be overtrained. If your muscles recover, but your nervous system isn't able to get back to a trainable state then you are overtraining.
This is very common with high intensity cardio. It takes a toll on your CNS and if you are doing that 4+ times per week then you will likely be struggling to recover between sessions. Some other types of workouts that lead to high CNS fatigue include going to failure with near maximal weights and plyometric/dynamic efforts.
These training methods are very effective and should not be avoided because of the CNS requirements, but should have plenty of recovery time between sessions and when you are not fully recovered, these types of training should be avoided.
How do you know if you are ready to train? There are two very simple at home tests for knowing. Grip strength and resting heart rate are both great indicators that are easy to measure. Using a hand dynamometer like this one from amazon can tell you your current level of preparedness by comparing to average measurements over a week. If you drop more than 10% below your average, you should take it easy on your workout. Measuring your heart rate first thing in the morning is another indicator. The challenge here is that it really has to be first thing in the morning, before you even get out of bed. If you get more than about 4-5 beats above your average resting heart rate, then you are not prepared for an intense training session.
How do you recover between workouts? What if you tested your grip strength and you aren't ready to train? There are many things you can do. Most of them are commonly recognized as "being healthy".
Get your sleep. The average adult needs 6-8 hours per night. That varies per individual, so try 8 for a while to baseline how you feel and then lower it and see if you have a decrease in recovery. Sleep quality can be improved by sleeping in a cool, silent, and pitch dark environment. Try to avoid blue light for at least 45 minutes before bed and get 10+ minutes of bright sunlight when you wake up.
Move your body. You recover better when walking and doing mobility sessions rather than just sitting around all day. Movement is medicine.
Get the nourishment your body needs. Recognize that a caloric deficit will mean that you recover slower, so you need to be aware of that. Getting a nutritious and macro-balanced diet will help your nervous and muscular recovery.
You can also try contrast showers, ice baths, or similar cryotherapy to help your nervous system kick up the recovery.
What does this mean for you?
- Recognize that recovery is required in more than just muscular systems
- Balance your training with some days/phases that are more intensive of the nervous system and some that require less
- Learn to connect your nervous system into your exercises
- Stimulate your nervous system before the main portion of all of your workouts.