The missing piece

He/she doesn't look that big, how are they so strong?  I have heard expressions like this for years and I am sure that there are many people out there who don't grasp the concept of training for strength and power versus training for size or muscle. 

The average person puts muscle size and strength together, usually thinking that bigger means stronger.  They think that bodybuilding training is the one and only way to get big and strong.  Now, muscle cross sectional area is one part of the strength equation.  The bigger and more muscle that someone has, the more potential they have for strength.  The piece of the puzzle that most people don't know about is the very important role that the nervous system plays. 

Neural factors that determine strength are intramuscular and intermuscular coordination.  With intramuscular coordination, recruitment of motor units, rate coding or firing rate, and synchronization of motor units all come into play.  A motor unit is made up of a motoneuron in the spinal cord and the muscle fibers that it innervates.  It is a basic element of motor system output. When you perform movements, your nervous system uses these motor units to activate muscle fibers and execute movement. Taking these three factors of intramuscular coordination into consideration, maximal force is acquired when a maximal number of motor units are recruited, rate coding is fast enough and at the desired level, and motor units are activated in sync during the maximal effort. 

Where intramuscular coordination deals with a single muscle group, intermuscular coordiation deals with the coordination of numerous muscle groups.  Movement patterns must be trained rather than just single muscles.  For example, if someone trains their quads with a leg extension, this won't necessarily carry over to a strong squat since they don't have the intermuscular coordination to execute the movement pattern efficiently.  You have to train movement, not just muscles, to become stronger. So if someone has a supercharged nervous system that works efficiently and effectively, they can possibly be a lot stronger than someone who appears to be bigger and more muscular. So how do you train your nervous system to work like this? 

Keeping it simple, by training fast and explosively with lighter weights and training max strength with heavy weights, for multiple sets of low reps, usually in the 1-3 range but as high as 5 depending on what you are trying to do at the time.   Ultimately, you need to train muscles and the nervous system for optimal performance whether you are an athlete or someone trying to get in shape. There will usually be some carry over between different training modalities (e.g. max strength will help build muscle and vice versa) but hopefully you now realize that there are more pieces to the puzzle than just training to get big muscles.