300418 Physiological factors affecting strength gains

300418 Physiological factors affecting strength gains

The organism rapidly adapts to the load or intensity due in part to ‘an enhanced level of to neural facilitation’… which ‘probably accounts for the rapid and significant strength increase early in’ the ‘training, which is not necessarily associated with an increase in muscle size and cross-sectional area’.

These neural adaptations are thought to be by-products of improvements in the efficiency of the neural recruitment patterns, increased activation of the nervous system, greater enhancements in the motor unit synchronization capabilities of the muscle fibers, a lowered inhibition of the neural reflexes and an inhibition of the Golgi tendon organs. Taken in order then we have the following psychological neural factors that are thought to influence the development of strength in the human body.

Improvements in the efficiency of the neural recruitment patterns

The central nervous system and the muscles will adapt to the load imposed upon them during the training process. Employing the greatest possible loads within tolerance levels (maximal effort training) evokes the greatest rewards. During this time the maximum amounts of motor units are recruited and the central nervous system inhibition, if it exists in the athlete is thereby reduced with this approach. The highest number of motor units, activated with the greatest discharge frequency within the “biomechanical parameters of movement and intermuscular coordination are similar to the analogous values in a main sport exercise”.

An athlete must have the ability to learn to magnify and memorize these changes in the motor recruitment patterns and firing order in order to succeed in the strength sports. These changes have to come at a subconscious level of thinking. Proper training cycles and intensity of effort will develop this subconscious thought process.

230418 Physiological and muscular effects on the expression of strength

230418 Physiological and muscular effects on the expression of strength

So you just bought the latest greatest training program and are making phenomenal gains. Congratulations on your progress, but have you considered just why the new training schedule is working so well? Let me explain the process a bit. The factors that affect and modify the expressions of strength in the human body have been extensively studied and written about.

The research concerning the body’s response to strength training regimens consistently refers to two major identified contributors in this enhancement process. Some of these studies are directed at and lie within the physiological and muscular systems of the human organism.

The early developments of strength are a direct result of neural adaptations to the training schedule. It is interesting to note that the majority of strength training studies examining programs claiming outrageous results involve short term training programs. In fact, most changes in a training program, unless they are wildly off the chart, will be able to produce measurable outcomes of a positive nature simply because of the phenomenon of neural adaptation to the new stresses on the organism.

This is a further adaptation of the SAID (specific adaptation to imposed stress) theory as first proposed and stated by Hans Selye back in the mid 1950’s. The crux of the theory is the body will adapt to the stress placed upon it. If this training stress, i.e. load volume or intensity is set at the right level, the body will overcome it and become stronger in anticipation of encountering the same in the future. In the beginning of the training program this is generally easily accomplished so no harm comes to the body. If, however, this stress is at too great of an intensity or volume the body breaks and fails to properly recover.

160418 Adrenaline[1] lifting

160418 Adrenaline[1] lifting

Lifting more than normal is not unusual under certain circumstances. This is frequently seen on the platform by athletes who make excellent use of their powers of generating positive result producing psychological and physical energy. In the gyms though, unless testing for a one repetition maximum, this is not a good training method.

The release of adrenaline, a hormone secreted by the adrenal medulla when stimulated by the central nervous system responding to stress, comes with limitations. It is not produced in great quantities and what is there is in limited supply until the body manufactures more over a period of time. If this is used too often, and excessively, it will eventually cause the body to use it but not realize the benefits.

This happens because the body begins to tolerate the initial stress response that caused the secretion in the first place and then disregards it. But the substance has still been released into the system. An increase in heart rate, blood pressure, carbohydrate metabolism and greater heart output results. All of which are stress responses. Essentially the body habituates to the influx of adrenaline and the energy that it provides is no longer realized by the lifter.

Left unattended these cause high blood pressure and heart problems.

[1] A hormone secreted in the adrenal gland that raises blood pressure, produces a rapid heartbeat, and acts as a neurotransmitter when the body is subjected to stress or danger

090418 Motor unit recruitment

090418 Motor unit recruitment

The size principle states that slow fatigue resistant motor units are recruited first. This theory serves to demonstrate the relationship between the motor unit twitch force and the recruitment threshold of the fibers.  For example these first muscle fibers are not able to sustain a lasting power output and give out rapidly. They do not have the ability to produce great force. Thus after lifting a certain number of repetitions the original fibers are fatigued and not producing the necessary force to continue. New fibers are then called upon to lift the weight. These new fibers are faster and much more powerful but also fatigue much quicker than the original fibers. These soon become exhausted and of limited use in the lifting process. But the advantage of this recruitment process is the majority of the muscles’ fibers have contributed all they can to the lift.  In other words the fibers have all been exhausted and will have to repair the damage caused by the lift in order to become stronger and better able to tolerate the resistance. The next time this load is placed upon them, they will have accommodated and grown stronger.

Training hint:

Training in such a manner as to inhibit the weaker fibers and going straight to the fast acting powerful ones is the key to instant and explosive force and power. Conditioning the CNS to bypass the non-power fibers occurs in some of the elite strength athletes. This takes the body a long time to make this adaptation and requires a deep dedication to the strength sport-more so than many people have at the lower levels of participation.

020418 Sport and lifestyle activity-range of motion exercising

020418 Sport and lifestyle activity-range of motion exercising

Your joints and muscles are meant to function within standardized degrees of movement, commonly referred to as the range of motion (ROM). The stronger you are within these ranges, the better protected you will be in preventing injuries from occurring. Therefore when doing your exercise routine keep in mind the following two guidelines:

  1. You gain the most strength within the range of motion (ROM) at which you exercise.
  2. The smaller the range of motion you in the joint, the less will be the carry over strength throughout the rest of the movement.

The basis of every quality strength training or fitness program relies, in part, on these two premises. As an example, let’s look at the squat while explaining these principles.

Many lifters do short range squats, known as high squats, in the gym. They get into a machine or in rare cases under a bar and drop down a few inches and call it good. In many instances this isn’t even to a parallel position, let alone below parallel where they should be before starting back up again. Depending on the load of the bar or on the machine, strength may be increased within this small range of motion but its unlikely this will happen.

This range of movement is too little and does not support normal living activities such as sitting down in a chair and then getting back up. If the strength is not developed within a range that is vital to living an active lifestyle then it is not useful. This group of fitness enthusiasts would be better served by going deeper in their squats, thereby getting a transfer of useable strength into their daily lives. This naturally leads in to the second principle.

An individual or strength athlete will become stronger when training the full range of motion. This expands the strength curve and transfers more useable muscle activity across greater degrees of the joint angle. Greater degree angles of strength protect the joint from injury, especially at the far ranges of motion.

The take home message is don’t cut yourself short with limited range of motion exercises.