Lets look at the main mechanisms of neural adaptation:
1. Increased Motor Unit Recruitment
This means neural adaptation to training that rapidly increases the strength of a novice who hasn’t yet experienced hypertrophy. What is a motor unit? A motor unit is made up of a single motor neuron, as well as all of the muscle fibers that neuron activates. This refers to our skeletal muscles, which are made of hundreds of thousands of fibers. These muscle fibers are activated by motor neurons when they receive signals from the brain to contract the muscle. A single motor neuron can control several hundred muscle fibers at a time, depending on the size and function of the muscle.
Why is it good to recruit more motor units and how does it relates to strength gains? Even when you engage in very low intensity activities, like lifting a glass to your mouth, your brain recruits motor units that have a smaller number of muscle fibers to allow you to lift the glass.However, when you are lifting something extremely heavy or applying a lot of force your body will contract more available motor units to allow you to perform the activity.
Your brain is a very clever mechanism. Imagine what would happen if your brain told your muscles to contract fully when lifting a glass up. You’d be knocking yourself in the face every time you wanted to have a drink. Motor unit recruitment is a trained and learnedability. The more motor units you can recruit, the more muscle fibers you can activate. The more muscle fibers you can activate, the more force you can apply.
2. Coordination of Motor Unit Recruitment
As mentioned above – as the athlete training progresses, his or her ability to utilize multiple motor units increases. Please note that each muscle fiber in a motor unit is functionally identical, which means it is either slow twitch or fast twitch, never both in the single motor unit. Training increases the total number of motor units that affect a muscular contraction. In other words, trained individuals can recruit more motor units than novices.
3. Increased Frequency of Firing
The frequency of motor unit firing increases with the training, as well as the total number of motor units that affect a muscular contraction. More motor units work together and they fire more rapidly (faster).
4. Improved Technique and Skill Acquisition
Out of the two similarly sized men, the one whose technique is competent will be able to generate more force than the novice. Also, he will do so in a safer manner.
5. Cross Education
Increased involvement of the neural pathways contributes to strength gains, too. For example, an untrained arm will gain significant strength in concert with a trained arm because of interaction between the nerves of either arm at the spinal column. This cross-education is one of the clearest demonstrations of neural adaptation.