Adaptions to Resistance Training (Neural)

    If you have been reading this blog you have figured out at least two things about my philosophy concerning exercise. I favor Resistance Training over aerobic training. Aerobic training does have merits and can be incorporated into resistance training. Plus, if you are having one of those day getting running will put you in a good mood. There is science to it, but it is a conversation for another day. The second is having a goal pertaining towards working out. I've extensively covered having a goal and how to build a program around that goal. Today's post is about resistance training and the neural adaptations that happen when you lift weights. 

    Neural adaptations are adaptations that your brain makes when consistent resistance training is applied. When you first start resistance training neural adaptations take place before any structural changes. Meaning before you start seeing "gains" in the motor cortexes in the brain that send signals to your muscles adapt first (hence why it is first in this series). The way the brain sends signals to the muscle is equivalent to a simple circuit with a battery, wire, switch and light bulb.  Battery is the brain (source of power), wire is the alpha motor neuron, switch is the Neuromuscular junction (Where the nerve attaches to the muscle) then the light bulb is your muscle. As you train the signals change in three aspects: rate coding, recruitment and greater synchronization within the mind muscle connection.

    

    Rate coding refers to the firing rate of the muscles that are being worked. As you lift heavier weight the mind sends increased signals to the muscle that increase the firing rate. Think about when performing a set of ten squats. The muscle is under tension and needs the brain to send firing signals to complete the ten reps. As you train more those signals become faster and faster.

    Muscle recruitment is simply how many muscles does the motor cortex need to recruit to lift the weight. If I am squatting 200 pounds, then my brain has to recruit enough muscle fibers in order to lift the associated weight. In the squatting example every motor unit (collection of muscle fibers that one nerve innervates. Eye muscles might have one or two motor unit while the quadricep has multiple motor units). When a motor unit is activated every muscle in that encompass that motor unit activate. This principle is called the All-or-nothing Principle. In terms of recruiting smaller, type 1 muscle fibers first then larger type 2 muscle fibers. One exception to this is selective recruitment. This is when highly trained athletes such as Olympic athletes and professional athletes recruit type 2 muscle fibers first then type 1. Smaller muscles rely more on rate coding while larger muscles rely more on recruitment. 

      Greater synchronization of motor units is another adaption to resistance training. Synchronization is the timing of motor units into a more focused approach. During a firework show fireworks are lit one or two at a time to extend the show; now imagine all the fireworks are tied together into one giant firework. Thats the synchronization adaptation.

    As you continue to lift weights it takes less neural activation to lift the weight in order to combat this progressive overload is needed to continue adaptations. Steadily increasing the total volume of the workout will continue to have adaptations.