Isometric Training in the ‘Skill-Stability Paradigm’

This is a 3- part series on isometric training and how I implement it as a preparation coach in fast bowling in cricket. Fast bowling can be seen as the equivalent to a pitcher in baseball with a run up. Very similar to a javelin throw. The forces involved in fast bowling are higher than most athletic skills and isometric training is essential to the effective completion of the skill. Isometric training forms the basis of my coaching system called ‘the skill-stability paradigm’.

This is my fast bowling intervention model that combines technical work with the overload capacities of strength training. It is a unique model that guarantees a transfer of training. In the first installment, I will cover the basic biomechanical requirements of fast bowling and how isometric training can be used to improve bowling performance in particular managing muscle slack and training the stretch shortening cycle [SSC].

Here is a video of the fastest bowler in the world at the minute. Australian Mitch Starc.

Isometric training. Where does it fit into my coaching?

Isometric training has been around for many years. Their popularity comes and goes based on a particular S+C who endorses them at that time. Be it Bob Hoffman in the 60’s and 70’s to my mentor Christian Thibaudeau and Inno-sport and DB Hammer in the early 2000’s and recently Triphasic training with Cal Dietz, Matt Van Dyke and also Max Schmarzo.

It’s a great honor for me to write another article on ‘Thibarmy’. ‘Thibs’ has inspired me for the last 15yrs both as a player and now as a coach. It seems Isometric training has had a resurgence so it’s a great time for me to explain how I use them in my fast bowling coaching system.

Isometrics have waved in and out of popularity because they have the potential, when used correctly, with the correct neurotype to build enormous strength. However, it’s difficult to measure progress when pushing against an immovable object or holding a heavy weight for an allocated time. How can you quantify progress?

This leads to many athletes and coaches having a reluctance to use them. However, Isometrics form the foundation of all I do with my fast bowling system. It is the base where all other methods are built upon. It’s stage 1 of my skill stability paradigm. There are 4 stages to the paradigm and each build on the previous stage.

  • Stage 1- Static- Holding the key bowling positions
  • Stage 2- Dynamic- Constraining parts of the action whilst adding in movement to others
  • Stage 3- Ballistic- Adding explosive and coordinative aspects to the sequence
  • Stage 4- Complex- Combining all the above methods

I believe there are 7 ways to change movement. Isometric training fulfills 90% of the criteria.

  1. Stabilize the attractors
  2. Manipulate TUT [time under tension]
  3. Create feel
  4. Feed the mistake
  5. Overload the movement
  6. Change the goal
  7. Add variability [complex/OU implement/Chaos/Fatigue]

There are six isometric based training methods that I use to train within the ‘7 principles of change’.

  1. Yielding isometric
  2. Overcoming isometric
  3. Functional isometric
  4. Iso-miometric
  5. CO-Contractions
  6. EQI’s

They are used periodically to increase general strength, increase muscle mass, strengthen a weak pint at a particular lift, increase mobility, aerobic capacity, strengthen key nodes in the technical model and also for biomechanical re-mapping.

I will cover how I use the techniques in the second part of this article. However, it is essential we briefly touch on what are isometrics, types of muscle contractions, and the role of isometric contraction in the stretch shortening cycle.

Isometrics. What are they?

In simple terms, isometric training refers to exercises where the muscles are producing force without movement. It can be achieved by either pushing/pulling against an immovable resistance or by holding a weight in a certain position.

‘An isometric contraction of the muscle occurs when the tension developed within the muscle is equal to the external load imposed upon the muscle’- Van Dyke and Schmarzo 2017

In both cases, the intent is different, but the external result is the same. Trying to move a resistance that can’t be moved is called overcoming isometrics (you are trying to overcome the resistance), whereas holding a weight in place, preventing it from dropping down is called yielding isometrics. As previously mentioned there are other types of training methods but they all are built around these two.

Although they look similar, they have slightly different training effects. On the outside, both lack movement however inside there are small, micro contractions of the muscle fibers which have different training effects

Overcoming isometrics have more transfer to concentric strength and are more neurologically demanding. They are best suited for short, very intense efforts, for neurotype 1A and 2A athletes, and have a greater impact on strength than size. There is no eccentric contraction involved.

As a side note, Type 1B fast bowlers rarely do any isometric work as they need to utilize the SSC [Stretch shortening cycle]. They spend more time on reflexive training, like ISO-catch or ISO switch. It is essential that they also have an eccentric and dynamic element to their training.

This video shows an overcoming isometric exercise overloading the key node of front foot contact

This is another overcoming isometric exercise but focusing on the back-foot contact

Yielding isometrics have more transfer to eccentric strength and are less neurologically draining. As such, they can be done for longer and work best to increase size than strength in a lift. They also work great on corrective training where key muscle groups are isolated and contracted. They suit neurotype 2B and 3’s. Both isometric training methods can have a positive or negative impact on the training of each neurotype.

I will discuss this in more detail further in the article. For example, a Type 2B fast bowler should very rarely be perform overcoming isometrics as the max intent and the lack of ‘feel’ created will cause them to over train and ultimately fail on their journey to add bowling velocity-their CNS will be fried!

Clip shows a young bowler holding aqua bags in a yielding 30secs isometric hold. It’s a progressive exercise after a basic bodyweight hold. On achieving a stable 90sec hold the bowler would progress to added resistance and perturbations via the aqua bags.

This clip shows a bowler holding a yielding isometric contraction with added dumbbell weight. This is an advanced drill and specific to a neurotype 2B.

Isometric contractions serve two functions in fast bowling. Stability and transfer of energy. Key muscle groups in the kinematic sequence of fast bowling have different roles to play during each delivery [execution of the skill].

On back foot contact the muscles around the trunk [oblique’s and erector muscles] work as stabilizers whilst the muscle tendon unit [MTU] around the lower leg work dynamically to firstly absorb force, equivalent to five times of the bodyweight, stabilize as to not sink/collapse and then explode and propel the fast bowler forward into front foot contact which has nine times bodyweight of force travelling up the body.

In one key node of the bowling action the body utilizes isometrics in different ways that work together to guarantee a successful completion of the skill. There are four key nodes in fast bowling. When the back-foot lands [BFC], when the front-foot lands [FFC], when the ball is delivered [D] and follow through [FT] which bring the process to a slow end.

There are other actions, but the four key nodes are the key determinants of a successful delivery. In each kinematic segment there is an eccentric, isometric and concentric contraction. The timing of these is crucial and depends on training and also anthropometry. More on that later. Performing these actions requires key parts of each sequence to fire accurately.

While beyond the scope of this article to go into too much detail but, co-contractions around key joints that eliminate muscle slack, back foot contact, and pre-turn—along with various reflexes such as crossed extensor reflex and stumble reflex—all have a direct impact on attaining each of the three main nodes/hard skills.

Isometric training has a direct impact on each of these aspects. This is why technique always come first in my intervention layer, where isometric training provides the key training method for biomechanical re-mapping during stage 1 of skill-stability. Power and strength is built upon the technique to maintain stability and transfer power from these key “attractor” sites that are specific to the skill being performed.





Photo credit-James Smith. ‘The governing dynamics of coaching’

Like most athletic actions it’s not about building robots who perform the same way; it’s about making sure the “attractors” which are the key basic, essential, fixed movements—are stable and reduce the degree of movement in the technical completion of the action. Isometric training limits the degrees of freedom.

The individuality and idiosyncratic elements are the “fluctuators,” changeable components that have degrees of freedom that do not negatively impact bowling performance. Fluctuators help us adapt to the environment but are specific to individual bowlers. It’s their own method of organizing and adapting to the environment (self-organizing)

These are the “big three” hard skills/attractors, for bowlers, in my opinion:

  • Hip shoulder separation
  • Star position (long arm pull)
  • Braced front leg

Isometric training has a direct and an indirect impact on whether the fast bowler can hit these 3 attractor sites. When training, these three attractor sites are at the core of every exercise. Whether in an isometric hold or a ballistic medicine ball throw.

The role of isometric contraction: Fascia and muscle

Three muscle action phases occur in EVERY dynamic movement. Again, regardless of the exercise/movement being completed, there is always a coupling of eccentric to concentric contraction with an isometric occurring in the middle as the muscle fibers change their direction.

However recent research suggests that muscles action may behave in a different way than first thought. This new way of thinking may place more of a focus on isometric training and its sudden resurgence in popularity.

It is widely assumed that there is an eccentric muscle fibre action during all dynamic actions, like fast bowling. However, recent studies, admittedly on animals and modelling studies in humans show the contractile element (CE)/muscle elements maintains an isometric contraction while the elastic/fascia (tendinous) element actually stretch and the muscular elements stay passive.

Therefore, there may actually be no significant eccentric, but rather predominantly an isometric action of the contractile elements during fast bowling. This new research has massive implications on how we physically train fast bowler and in actual fact any coordinative and dynamic muscle action.

‘Based on this, we propose that isometric rather than eccentric exercises is a more specific way of conditioning the hamstrings for high-speed running’

-Van Hooren, Bosch 2017

The stretch shortening cycle [SSC]

However, for the purpose of this article I will explain how I use isometric training in my ‘skill stability paradigm based on a combination of the new idea of muscle action and the traditional thinking. This isn’t to devalue the recent research as I place a high regard on the idea of ‘eliminating muscle slack’ in my coaching philosophy. I believe it is a key determinant of fast bowling performance.

Energy is stored and utilised in the muscle via a process known as the stretch- shortening cycle (SSC). During the SSC, the muscle goes from a lengthening (eccentric) muscle action to a rapid shortening (concentric) muscle action. The isometric contraction phase is called the ‘coupling time’ and can be seen as the ‘bridge’ between eccentric and concentric.

The time spent on this bridge [also called the amortization phase] is a key determinant of sports performance. Most skills and sports action occur under 0-25sec, which is the time it takes for a highly trained athlete to complete the SSC when performing a barbell lift. Isometric strength plays a critical role in executing the sport skill in a synchronized, efficient, and explosive manner as force is transferred through these muscle action phases.

When all else is equal the athlete, who is able to switch from eccentric to concentric and therefore spend less time in the coupling time [isometric] will be the quickest and most explosive athlete.

Eliminating muscle slack and strengthening co-contractions

What is muscle slack?
Imagine a rope bridge that is loose versus a bridge that is tight before you want to walk across it. The time it takes for the ladder to tense to have enough tension for you to walk over on it is called ‘muscle slack’. In fast bowling or any athletic skill, it is time lost.  One of the recent proponent of muscle slack is Dutch athletics coach Frans Bosch.

He believes that the speed at which muscles can build up their tension and overcome muscle slack is usually more important to performance than the amount of force they can eventually produce. This is why technique and sequencing are more important for fast bowling than any strength training in my opinion.

This concept of muscle slack is also why in a basic single response jump a smaller countermovement, or the quick dip and drive is so effective in adding inches – it pretensions the muscles. However, there is a balancing act and anthropometry often dictates the amount of ‘dip’ or ‘pre-tension’ required to store energy. There are two types of fast bowlers. Knee or hip dominant. Knee dominant fast bowlers need more movement to access the SSC.

Whereas highly reactive and stiff hip dominant fast bowlers require a smaller ‘dip’ as the elastic recoil in the tendon is what generates the movement. This has massive Implications for strength and athletic preparation training. Knee dominant or as they are often called static, pushers and muscle driven athletes, as opposed to spring, pullers and fascia driven hip athletes are required to have the ability to manage muscle slack more effectively than their more stiff/reactive counterparts.

This is why isometric training is essential for a knee dominant bowler. They haven’t the natural capacity to manage the slack so isometric training is essential to them. However, the majority of training has a disproportionate focus on the concentric element of strength training and muscle slack has reached worrying levels in cricket.

In cricket, the best bowlers make smaller countermovement’s and allow storage of elastic energy to work. However, in the modern age of ‘S&C job justification’ training based on large countermovement’s like back squatting will lead to longer muscle slack and poorer performance. Knee dominant fast bowlers who require the use of large counter movements when delivering the cricket ball are trying to take the slack out of their system.

A fast bowler with a lot of muscle slack is not springy and takes a too much time to generate force. Plyometric exercises that involve a rebound like a depth jump, absorption exercises to teach the muscles to co-contract and develop tension quickly like depth drops, and isometric exercises help eliminate muscle slack in the fast bowler.

In my often-controversial opinion, I believe there is a mismanagement of muscle slack that has reached epidemic proportions in athletic preparation training. Managing muscle slack is one of the most performance determining factors in fast bowling. The inaccurate focus on the concentric portion of weight lifting/general strength training has led to a culture of using training concepts that may actually be counterproductive for one of the most explosive and coordinative sports skills going, fast bowling.

It is assumed, and I was one of them that if an explosive concentric contraction was preceded by an eccentric contraction then the subsequent dynamic action will be a more powerful movement. However here it falls short. As previously stated the SSC takes 0.25sec (250millisecond) to complete. Any longer it’s seen as a longer contraction and any shorter will be seen as a short one.

Most artificial (gym/strength/compound/jumps etc.) explosive movements will be around the 0.25sec mark and these are seen as the sport specific exercises in the gym. This is the foundation of velocity-based training [VBT] and the measuring of bar speed. However, I do question its value but open to being convinced otherwise. Yes, I understand the whole ‘training the full curve argument’ but currently my training has gone in a different direction.

Due to this inaccurate focus, we have developed a generation of ‘knee dominant pushers’. Most fast bowlers now have a poor technical model due the over emphasis on heavy strength training and engraining the squat pattern over reactive training methods. The ‘gym whiteboard’ syndrome as led to strength and conditioning coaches focusing on ‘big lift’ numbers to justify their existence in a highly skilled coordinative sport like cricket.

Yes, don’t get me wrong strength is the foundation of athletic skills, however there is a cutoff point that most don’t abide to. Increasing large compound lift numbers has led to fast bowlers having the inability to manage muscle slack. Strength does not have time to impact on fast bowling performance.

I’m a huge fan on spending a short amount of time on BFC (back foot contact) with a stiff landing in bowling as it allows the whole kinematic sequencing to occur effectively and efficiently. The kinematic consequences of a stiff contact are massive.

Stiff contact=short contact= crossed extensor reflex= long delivery stride, hip shoulder separation, foot plant from above and swing leg retraction.

Having a slow, heavy and labored back foot landing where the knee is flexed to access the SSC is not conducive to bowling quickly. By the time the foot has pivoted, called the pre-turn the front foot has landed, and the hips and shoulders have not fully separated. This leads to injuries due to lateral flexion of the spine and also issues up and down the kinetic chain due to energy blockages. Bowlers end up having to build energy in other parts of the sequence which leads to a ‘clunky’ inefficient bowling action.

The fastest bowlers in the world, such as Mitch Starc and the now retired Brett Lee spend approximately 0.07-09 on BFC and this is evident with the heel not touching, they take approximately 0.12-14sec to go from BFC to FFC and finally 0.10-12sec to release the ball from FFC to delivery. As you can see the highly coordinative bowling action doesn’t rely on the SSC if done optimally.

Here is one of my young fast bowlers. Notice his back foot on landing. He weighs 58kg but bowls 83mph. Not sure it’s due to his strength numbers!

Muscle slack can be trained via ISOMETRIC training. The immediate and high intent action of going from relaxed to maximum tension stabilize the co contractions and limit muscle slack around the key attractor positions of the bowling action based on the position trained.

Having the ability to eliminate muscle slack is having the capacity to make the most out of our elastic muscle properties in movements. Elasticity refers to the ability to return to normal resting length following a stretch.  Our muscles have contractile elements [the muscle] and SEC (series elastic components) which is the elastic element such as our tendons and the intrinsic elasticity of the myofilaments. The SEC or muscle’s elastic components have a major impact on force production. The SEC’s also function as shock absorbents in unfamiliar, changing environments.

The capacity for the MTU [Muscle tendon unit] on the lower leg on back foot contact, to absorb, store and recoil is based on the ‘spring mass model’

Elasticity and isometry work together. Both work synergistically. However, when a skill requires more of one, the other changes its function. Speed skating involves no rebound actions and mostly explosive pushing into the ice, so virtually no elastic muscle properties. This is why the athletes have huge quadriceps development as the muscle is constantly under tension. The quads are in a permanent isometric contraction.

There is no ‘cheating’ of the movement from the elastic energy stored in the tendons. However, something like a delivery in fast bowling is highly dependent on the ability of the muscles of the leg to contract isometrically (think minimal knee flexion on BFC) so that the SEC produce elastic power like a pogo stick.  

During the skill of fast bowling there is not enough time to produce maximal force. As stated earlier both feet only contact the ground for a short amount of time and there is no way to use all the force generated in something like a heavy back squat.  Therefore, it is not the strongest athletes, but those that can produce the greatest force in the shortest time that have an advantage. Training to increase the rate of force development allows reaching a higher level of muscle force in the early phase of muscle contraction.

However please be aware I’m not against strength training. It has its place but has to work in partnership with the skills required for the sport and not to its detriment. It cannot be about those who lift the biggest numbers. That is ego driven on the part of the coaches and will ultimately lead to failure in a sport where coordination, transfer of power, tactics and technique is king.

“In beginners, strength training does have a positive impact on some aspects of rate of force development.” In most studies that don’t involve the elite, adding strength improves (or is correlated to) acceleration in the first few steps, jump height, and the ability to change directions’- F Bosch

 The main message from the 1st instalment is that strength training is contextual, meaning it is both vector specific and velocity specific. Eliminating muscle slack in training is essential and training with overload but without specificity usually has very little positive impact on fast bowling, especially in higher ability and higher training age players.

In the next instalment, I will explain how I use isometric training in my skill-stability paradigm. How it can build muscles around the attractor sites, how it can groove the correct motor pattern, how it can strengthen a weak point of a lift which transfers to fast bowling. Isometric training has been a huge part of my programme as a player and now has developed into the foundation of every aspect of my coaching tool box. To finish the three-part series, I will explain how Neurotyping will dictate what type of isometric training method I use.


Steffan Jones is the last dual professional sportsman in the United Kingdom having played 3 years professional rugby and 20 years professional cricket. Currently, he is Director of Sport Performance at a private school in England and a global fast bowling consultant. He travels the world advising coaches and players on the governing dynamics of fast bowling. Steffan is in a unique position having played the sport, is a qualified sports scientist, a UKSCA qualified strength and conditioning coach and also as a level 3 qualified technical coach. His methods are cutting edge and heavily based on sports science. He is the sole global cricket advisor for 1080 sprint and Realtrack WIMU. Steffan is also the only cricket coach to be qualified in teaching the Lila movement Exogen suit which he regards as the number 1 specific strength tool in the buisness. Recently, he became the first qualified Neurotyping specialist in cricket. Steffan has developed a reputation as an ‘outside the box’ thinker in cricket and is the go to man when an increase in bowling velocity is required. His foucs on specific strength including weighted ball bowling, the application of the Bondarchuk classification and the utilisation of Isometric training as part of his skill STABILITY paradigm coaching model has brought him plaudits from all around the world.


Written by Steffan Jones