• James Heath

Strength classifications

Updated: Mar 21, 2019

I am an experience personal trainer in Dubai, trying to pass on the right information about effective nutrition and training principles. This article spells out the fundamental classifications for strength and resistance training. If you're new to the gym it is very important to know these basic classifications.

It has been proven the amount of resistance or load used for a specific exercise is the most important variable in resistance training (McDonagh & Davies 1984). What this means is the amount of energy required to move the load and tension placed on the muscle is crucial for obtaining an adaptive stress response. The degree of loading is described as repetitions maximum (RM). For example, the maximal weight that can be lifted correctly four times without rest is 4RM*.

Maximal involuntary strength

Also known as limit strength, is typified by a survival (instinctual) response to a life-threatening situation that involves little or no prior thought or preparation.

Maximal strength

The peak force or torque the neuromuscular system can produce in a single voluntary contraction. The muscle contraction itself can be broken down into 3 types which can be trained separately.

*The relationship between repetitions maximum (RM) and maximal strength is known as 1RM continuum.

1. Isometric (static) contraction

Tension within a muscle without any external movement or change in length. The muscle and fascia do shorten internally while developing tension, agonist and antagonist muscles often counter balance each other. Some sports require an isometric contraction before the concentric contraction that generates movement such as starting out of the blocks in sprinting.

2. Concentric contraction

The muscle shortens while developing tension and thus causes movement to occur. During a bicep curl the joint angle of the elbow is decreased from 180 degrees to 15 degrees resulting in elevation of the dumbbell.

3. Eccentric contraction

The muscle lengthens while producing tension, breaking and controlling the speed of movement. An example is when controlling your landing after jumping where deceleration is required.


The ability of the neuromuscular system to create the greatest force in the shortest time possible. In other words your ability to overcome resistance with the greatest contraction speed possible. Also known as fast strength or elastic strength there are 3 sub categories:

1. Starting strength

The ability to generate maximal force at the beginning of a muscular contraction. Extremely important in sports that require great initial speed such as boxing and squash and is usually a key determinant for sports that have lighter resistance to overcome. As such it is dependant on the number of motor units within the muscle that can be activated at the beginning of a contraction.

2. Explosive strength

The capacity to develop a vertical rise in force once movement has been initiated, measured in terms of the continued increase in force. In other words, the rate one can develop maximal or peak force once movement has been initiated. Explosive strength is very important in sports such as wrestling, hammer throw or shot put.

3. Reactive strength

The ability to quickly shift from an eccentric contraction to a concentric muscle contraction (stretch shortening cycle). Reactive strength regulates performance in sports where the stretch shortening activity is great such as volleyball, basketball and weightlifting.


"Plyometric" refers of the enhancement of force development of the concentric contraction that happens straight after a rapid eccentric contraction. As such represents a form of training that purposefully aims to target fast eccentric contractions followed by fast explosive concentric contractions. Most professional sports will effectively utilise plyometric training to enhance speed strength amongst athletes. Exercise examples include depth jumps and bounded sprints.

Strength endurance

This refers to the tolerance against fatigue in strength (resistance) performances of longer duration. Typical the resistance would need to be greater then 30 percent of a personal 1 RM (some level of resistance) with muscle contractions maintaining a consistent force output over time. Strength endurance is characterised with high levels of strength levels and high levels of endurance. In other words, the stronger a person is the easier they will find maintaining a consistent force output of resistance below the 1 RM. Strength endurance is prevalent in most competitive sports including gymnastics, strongman, boxing and most team sports.

Absolute strength

The maximum force a person can generate irrespective of body weight and time. Basically how much you can lift.

Relative strength

The maximum force a person can generate per unit of body weight but irrespective of time. To a large extent why there is weight categories in sports.

Optimal strength or strength specificity

The optimal level of strength needed for a sport for further increases in strength would not boost performance. In sports where motor skill predominates, such as golf and tennis the level of strength is quite low.


I hope you find the classifications of strength helpful when trying to understand the fundamentals of your resistance training. If your in Dubai and wanting to start a body transformation program then please get in touch. If you want to follow a high quality online training program I want to hear from you. Finally please subscribe to my website for future updates and promotions.


McDonagh MJ, Davies CT., (1984) Adaptive response of mammalian muscle to exercise with high loads, European journal of Applied Physiology and Occupational Physiology 52(2):139-55