Introduction
I started my business called Pacelab Ltd in 2018 with the aim of effectively integrating sports science into the coaching of fast bowlers in cricket. My mantra is simple, ‘assessing not guessing’. Everyone in sports coaching has an opinion, and everyone is entitled to them. My intention is to deal in fact and quantitative data as well as qualitative data. This will in turn provide the scientific reason for all intervention methods in cricket. ‘If I improve that number, this will happen!’ It’s a definite shift from how I played the game, but data doesn’t lie. Issues in sport occur due to the poor interpretation and application of the data.
Ok, off the bat, having pinned my hat on ‘facts and data’ let me say this article is based on a ‘hunch’ and slightly away from my data driven approach but it is based on science. I may be applying it contextually in a way others wouldn’t and in actual fact may not have any grounding to be relevant to sports performance.
The Fast Bowler
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 ground contact time and muscle contraction times happen far quicker than any other skill. Apart from actual sprinting
Using the Muscle lab contact grid. Ground contact times [GCT] of 0.112 sec were observed on back foot contact [BFC] and 0.288 sec on front foot contact [FFC] which confirms my belief that SSC has little impact on the transfer of power from back foot to front foot contact to actual delivery in fast bowling.
Below is a list of different sporting activities, and the associated GCT related with each movement:
- Standing Vertical Jump: 0.5 sec
- Depth Jump off of 24″ Box: 0.2-.4 sec
- High Jump Take off: 0.14-.2 sec
- Long Jump Take off:0 .12 sec
- Sprinting: less than -0.10 sec
As you can see from these numbers fast bowling happens quicker than every sporting skill apart from sprinting. However fast bowling requires vertical lift as well as horizontal propulsion. It is unique and deserves all the respect sport science gives it. The faster the movement, the lower the ground contact time must be. Research has shown that, athletes with a greater percentage of fast twitch muscle fibres will do better in events, which require the lower ground contact times. So this is why I’m a firm believer and I’ve written about it before “Genuine fast bowlers are born”. Everyone can bowl faster and push the ceiling but a few factors including your fast twitch make up and neurotype dictates your pace floor. Some start in the basement and will only ever reach the 2nd floor, whereas your fast twitch racehorse will begin at the 80th floor already! This article will discuss these factors.
To perform any skill or physical activity as simple as walking the muscle employs an energy absorption, storage and utilisation cycle knows as the stretch shortening cycle [SSC]. It consists of an eccentric phase [absorption/pre-loading/stretching phase], isometric stage [storage/ coupling time/ amortization phase] and finally the body’s response and propulsion, the concentric phase [utilsation/ explode/ propulsion phase]
The stretch-shortening cycle (SSC) refers to the ‘pre-stretch’ or ‘countermovement’ action that is commonly observed during typical human movements such as jumping. This pre-stretch allows the athlete to produce more force and move quicker. Science of Sport [1]
SSC can be separated into two categories based upon the duration of the SSC:
- Fast-SSC: <250 milliseconds
- Slow-SSC: >250 milliseconds
“Rate of force development (RFD) can be broken down into two stages.
There is an early stage RFD and a late stage rate of force development. Early stage RFD is typically measured from 0-100ms while late stage RFD is anything after”
- Early- 0-100ms
- Late- 200ms+
Early and late stage RFD differs in terms of neural and physiological mechanisms. Late stage RFD might be much more related to the contractile elements of the muscle while early stage RFD might have to do more with the nervous system. Depending on the state of the athlete, specific shifts in training should be considered in order to obtain the best results in performance Strong by Science [2]
Training each node/segment different in a fast bowler in turn will groove a delay, a longer arm pull, create time and storing more energy in the upper half to allow time for the body to transfer momentum form BFC to FFC- as we know it happens in a fraction of a second. This in turn creates the natural ‘whip’ that a bowler craves for a genuine fast delivery.
There is a reason why we move like we do and perform a skill like fast bowling in the manner we do it. The body doesn’t gravitate to its strength but it moves towards its weaknesses. Also know as dysfunctions.
I believe there are 5 reasons why a fast bowler has the technical model they have:
- Myelinated motor pattern
- Fibre make up
- Neuro-chemical type [Neurotype]
- Training age
- Muscle or Tendon driven
Myelinated Motor Pattern
Hip or knee dominant bowlers
I categories fast bowlers into 2 separate types based on neural pattern and the angle of the back knee on contact with the ground. Some bowlers will land on back foot contact [BFC] with a knee flexion of 90” to 45” who I categorise as knee dominant bowlers and other bowlers will land on BFC with a knee angle of 45” to 10”. These I categorise as hip dominant bowlers. There is an anthropometrical and physiological reason why a fast bowler would land this way.
Ultimately, fast bowlers are built, and subsequently, developed for a particular bowling style. Through their adolescent development, their neurons that fired together to form a particular platform of movement become wired together to make that movement more powerful in their maturity.
With this classification, it’s more about a preferred motor pattern than exact muscle strength, which is the preference of squatting (knee) or deadlifting (hip). This is a myelinated movement patterning, so the best way to make any real changes is to get high volume or slow-speed performance of specific movements requiring neurally “steering” of the pattern towards middle ground, but this is only helpful to a point, since an athlete must ultimately embrace their strengths to reach their highest potential.
From the time, a child starts throwing their dummy out of the pram; the processes of neurophysiology are in play. To make a muscle work, the motor cortex of the brain initiates an electrical impulse that travels down a nerve, connects with another nerve at the spinal cord, and then activates a muscle contraction. In a complex movement like bowling, this occurs in a series of sequenced and synergistic events known as a neuromuscular pattern.
Every delivery of a cricket ball results in one layer of myelin (insulation) on that neuromuscular pathway. Make another delivery and you get another layer. Keep repeating it and you’ve myelinated a circuit that becomes the identity of your movement pattern. This pattern will follow anthropometry.
Technique cannot follow a path, which isn’t stable and functional. You cannot ask the body to do something, which it fundamentally cannot do! Early decisions in a bowlers’ development need to be made. Does training need to match the technique or the technique needs to match the physical profile?
Hip dominant pattern
Knee dominant pattern
‘Form is dictated by function, technique dictated by strength’
When a bowler learns to produce force in a particular manner through adolescence (this is usually done in accordance with the bowlers’ individual strengths) these patterns are wired in, and it becomes impossible to wire over it with another pattern. Kids sprint and jump from just a few years old, so these patterns are very hard wired. There are technical refinements that can and should be made to anyone but in general, wired movement patterns are hard to break. The correct pattern needs to be ‘wired’ early in the process.
Bowling technique will be dictated by how they move as kids. Some will utilize little knee bend and elasticity in jumping (hip dominant), while others use considerable knee bend (knee dominant). You can’t take either of these bowlers and expect them to jump like the other. In the same vein, you can’t take one bowler and expect the same training and the same technique to work for both. There are characteristics that need to be respected and embraced
The key question is. Have they developed that myelinated motor pattern of either being hip or knee dominant due to sociological and lifestyle factors or physiological as well as anthropometrical reason?
Other sports can follow this categorisation as I believe its relevant to all throwing and sprinting skills
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Fibre Make-Up
As previously mentioned fast bowling is one of the most explosive and highly coordinated skills a human being can perform. The forces imparted on the body are exponential. Ground reaction forces of between 3-5 times bodyweight have been recorded on BFC and 8-10 times bodyweight on FFC. Nothing in the gym can replicate these forces.
Fast bowling allows for ground contact times of a tenth of a second or less, which gives bowlers very little time to apply force. The short and powerful forces that are applied during fast bowling are a product of some of the following factors:
- Fast twitch fibre proportion
- Muscle fascicle lengths
- Tendon length and pliability
- Tendon insertion and moment arm of key joints (such as the knee and ankle)
- Nervous system strength and speed (central drive)
- Skeletal structure aspects (Bone length etc.)
ONLY SOME OF THESE ARE TRAINABLE. DNA does dictate your future
Fast bowling relies on the ability to tolerate and utilise these forces along with timing and coordination. It is not entirely about strength and in fact it has nothing to do with ‘gym numbers’ . I know of bowlers who weigh 59kg and can’t squat their own bodyweight and have a reactive strength index [RSI] less than 2.0 but bowl at 85mph. This is fast in any level of cricket. In fact, it is in the top 10% of bowling velocities. However, the key is finding if these are anomalies or a genuine reflection of how the human body works.
As mentioned earlier the period during which the muscle changes from an eccentric to a concentric contraction are called the coupling time and the greater force developed is associated with the shortest coupling time. Fast bowlers need to put as much force into the floor in the shortest amount of time- a big ask! Being fast twitch dominant or slow twitch dominant has a direct impact on this ability. A study was carried out on various jumping sports that have a direct transfer to fast bowling.
Bosco et al (1982) proposed that individuals with a high percentage of fast twitch fibres in the leg muscles exhibit a maximum plyometric effect when the eccentric phase is short, movement range is small, and coupling time is brief. [3]
So, do hip dominant bowlers have more fast twitch fibres?
Hip dominant fast bowlers tend to run in quicker to generate maximal horizontal velocity initially, a slight lowering of CM, a small movement angle as measured at the knees joint, and a resulting compromise between vertical height development and conservation of horizontal momentum in order to achieve the best possible resulting performance. So hip dominant fast bowlers make very good LONG JUMPERS
Whereas,
“…subjects with a high percentage of slow twitch fibres produce their best jumping performance when the eccentric phase is longer, movement range is greater and the coupling time is longer. Also the degree of flexion of the limb (e.g. knee when doing single leg hops) should not be too excessive because the larger the eccentric movement the greater the loss of elastic tension. The rate of stretch rather than the magnitude of stretch determines the extent of elastic energy boosting that the muscle receives following an eccentric contraction. (Hennessy).” [3b]
Does a knee dominant fast bowler have slower twitch fibres and to create time to develop a longer eccentric phase flex more at BFC?
Knee dominant fast bowlers have a slower approach in order to convert horizontal kinetic energy to vertical lift. This is achieved through longer ground contact times and longer coupling times over a greater range of motion. To achieve maximum power there has to be a conversion of force to velocity, yet the bowler is trying to achieve maximum vertical velocity in the shortest amount of time. Knee dominant fast bowlers would make very good HIGH JUMPERS
If you are a knee dominant bowler with a large flexion on BFC then this will require a lower ground contact times, as you need time to “stack up”, internally rotate at the hip and generate torque in the trunk. You can get away with not being so blessed in the fast twitch department.
So, are hip dominant fast bowlers more fast twitch than knee dominant fast bowlers?
What types of fibres are there and how does it impact fast bowling?
Characteristics of muscle fibers types in humans
Over the last several decades it has become common knowledge that the muscles of humans (and animals) contain two distinct categories of fibers, slow twitch and fast twitch. Slow twitch muscle fibers are also commonly labelled Type I, or red fibers, while fast twitch fibers have also been identified as Type II, or white fibers. Slow twitch fibers are genetically very well suited for aerobic metabolism and, therefore, endurance work. At the same time, they have a limited capacity for anaerobic metabolism. Spin bowlers tend to be slow twitch animals.
Slow twitch muscle fibers got their name because their time to peak contraction is approximately 110 milliseconds. While contraction velocities in this range cannot really be considered slow, they are relatively slower than those of fast twitch muscle fibers which are in the range of 40 to 60 milliseconds (Brooks, Fahey, and Baldwin, 2005). [4]
Fast twitch muscle fibers are very well suited for anaerobic metabolism but much less so for aerobic metabolism. They contract rapidly and powerfully but also fatigue more quickly than their slow twitch counterparts. Consequently, they are genetically best suited for sprint and power work. All fast or medium bowlers will be more fast twitch dominant. However, the type of fast twitch will have a direct impact on the ‘bowling type’ and the pace they can bowl at.
Fast twitch muscle fibers have been further classified into two subcategories, FTa, and FTx fibers. The latter were formerly designated FTb fibers.
Most humans are born with approximately equal proportions of fast twitch muscle fibers. The FTa fibers tend to predominate within the category, and the percentage of FTx fibers is generally lower.
While the middle 68% of the population have nearly equal percentages of fast twitch and slow twitch fibers, there are persons at either end of the bell-shaped curve who are born with either a much higher percentage of slow twitch fibers or a much higher percentage of fast twitch fibers than the general population. These bowlers tend to be the ones who bowl at higher velocities.
The fibre make up of a fast bowler has a direct impact on their bowling Kino-sequence.
The body will follow the path of least resistance in search of a movement pattern.
Do knee dominant bowlers, flex more on ground contact due their slower twitch fibre dominance or to be more specific more TYPE 2a dominance and is it a consequence of fatiguing quicker?
How are slow and fast twitch muscle fibers recruited during work?
A common misconception is that slow work is performed by slow twitch muscle fibers and fast efforts are executed by fast twitch fibers. Actually, neither of these statements is entirely true. Sub-maximal work is performed by the more aerobically efficient slow twitch muscle fibers while progressively more and more fast twitch fibers are recruited to assist them as the effort increases toward maximum.
Large muscles like the bicep femoris, are made up of groups of muscle fibers served by a single motor nerve. These groups of fibers are termed motor units. Each motor unit contains fibers of a similar type. Thus, even though a large muscle may contain all three fiber types, the fibers within a particular motor unit will be of the same type, either ST, FTa or FTx.
Research has show that knee angle directly impacts on muscle activation in the leg.
‘…Bicep femoris and overall posterior chain muscle activation increased with the knee positioned at 30 degrees…’ Applebee et al [5]
The hamstrings are more actively involved, especially Bicep Femoris when the knee isn’t largely flexed on BFC. When back knee flexed greater than 45% degrees it becomes more about the anterior chain and gluteus maximus.
There are 2 principles that need to be understood regarding muscle fibre recruitment that impact on fast bowling:
- All or none law
- Size principle
Motor units obey the “all or none” law. That is, if the nervous stimulation is sufficient to cause the fibers within a motor unit to contract, all of the fibers in the unit will contract with maximum force. Thus, the muscular force that can be applied by an athlete is largely due to the maximum number of motor units contracting at any one time and the types of motor units that are contracting. The motor units of slow twitch fibers usually contain fewer than 300 fibers, whereas, the motor units of fast twitch fibers have anywhere from several hundred to thousands of fibers.
‘The order of recruitment is commonly known as the “size principle” of muscle fiber recruitment. The order of recruitment is from ST to FTa to FTx motor units as the intensity of work increases. This is because of the size of the motor nerve innervating the different categories of motor units. Smaller motor nerves require the least amount of nervous stimulation to excite their motor units to contract. Slow twitch muscle fibers have the smallest motor nerves so they will be recruited to perform work that is easy to moderate in nature. Motor units with FTa fibers have larger motor nerves and require a greater neural drive before they will be excited to contract, therefore, they will not be recruited until the work intensity is beyond moderate. The motor nerves of FTx fibers are the largest of all so they will not be recruited until the need for force and power approaches maximum’ [6]
To summarize what was said before, at low levels of effort it is primarily the slow twitch muscle fibers that do the work. When the effort increases, fast twitch muscle fibers will be recruited to assist (not replace) their ST counterparts. FTa fibers are the first of the fast twitch group to be recruited as the effort increases, with FTx fibers recruited to assist both the ST and FTa fibers as the effort approaches maximum.
Taking weight training as an example;
‘An individual with a high ratio of FT fibers or an efficient nervous system can recruit his FT fibers at a lower percentage (10-15% earlier so starting at roughly 65-70% of relative effort). Since the FT fibers are not as fiber resistant. If you can bring them in sooner in action they also fatigue sooner and you won’t be able to do as many reps with a given percentage. This is also why if you activate/excite the nervous system your maximum strength (weight you can lift 1-3 times) and power can increase while your “high reps performance” can seem to go down. This individual is more at risk of overtraining when doing more reps and by going to failure. This individual is quickly affected by reaching the red zone. His next set performance will drop significantly and he will feel a mental drain’
On the other hand someone who is slow twitch dominant or not neurally efficient they will require a greater relative load to fully recruit the FT fibers. (5% more so full recruitment starting at around 85%). Our individual fatigues at a slower rate for the first part of the set. Once he recruits the FT fibers, fatigue is the same. But it requires a lot more reps to finally recruit the FT fibers AND you cannot do a lot of reps once you reach max recruitment. He thus stimulates less growth per set. However this individual is less at rislk of overtraining via excessive volume. The red zone has a lesser impact on him too. In fact oftentimes it has no ill effect on the next set and very little impact on the nervous system (within reason) This individual will have a hard time stimulating a lot of growth if he doesn’t train in the red zone. Otherwise he wont have enough reps with maximal effect unless he doubles his number of sets (and this bring the problem of glycogen depletion)
– C Thibaudeau
Implications for Fast Bowlers
Based on these 2 principles I believe fast bowlers are affected in various ways. The question I have based on this knowledge on muscle fibres is this;
Knee dominant bowlers, who flex on contact to increase time to access the longer SSC in their type 2a dominant muscle fibre type will never get the opportunity to utilise the explosive power of the type 2b as the action of delivering the ball happens before the slow type 1 fibres fatigue
They simply have too much type 1 and type 2a fibres to fatigue before they tap into their full potential.
The majority of fast bowlers are type 2a in my opinion. Most are explosive and quick but not really ‘super quick’ and as what I call ‘genuine fast bowlers’. So, this theory is more relevant to them. Important to mention both hip and knee dominant would fall into this category. From experience I often was more explosive and bowled quicker after bowling 18-24 balls. At the time I put it down to simply be fully activated, mobile and warmed up. However, I have now got a new take on it. The volume of the ‘warm up’ deliveries also varied based on the training I performed in the winter prior to the season. When I focused on strength work I bowled quicker with little warm up deliveries but lost the ‘engine’ to keep going. I hit a wall very quickly! However, when I trained differently with more focus on running and conditioning I still bowled quickly but it took longer to get me up to speed. So, it looked as if I bowled for longer periods but in fact I was just bowling at 60-70% for longer.
Often bowlers are complemented on being ‘fitter’ and better conditioned if they can bowl many overs. However, is it due to an overemphasis on ‘oxidative’ and slow twitch focused training in the preparation period that has now led to the bowler being more resilient but now unable to tap into the HTMU [Higher threshold motor units]. They can bowl for longer but have lost bowling velocity.
I have 2 training ideas that I will be trying this year. The aim is to target muscles and pre-fatigue fibres prior to bowling. Yes, it sounds counterproductive to an explosive skill like fast bowling but based on the 2 principles I think it may just work. They key is to not produce too much neural and general muscular fatigue that interferes with the skill itself. It can be seen as a ‘high repetition PAP’ method. As a side note I am a huge advocate of PAP training and perform it extensively. Contrasting a heavy maximum strength or isometric lift with a specific explosive exercise that replicate fast bowling or the movement as a whole. This new idea is a different concept.
As opposed to waking the fast twitch fibres like a traditional PAP Contrast method, my aim is to fatigue the slower twitch fibres to allow the fast twitch fibres to function appropriately.
Occlusion training could provide the solution. What if we were to localise fatigue key muscle groups that are involved in fast bowling? What if we performed hamstring curls for a hip dominant bowler or quad extension for a knee dominant bowler with occlusion cuffs or blood flow restriction bands prior to bowling a delivery. This would guarantee a hip dominant bowler on front foot contact, during swing leg retraction that bicep femoris is actively involved in completing the action
“The Blood Flow Restriction (BFR) bands reduce oxygen supply to the muscles that will pre-fatigue slow twitch muscle fibers and diminish their response to workout loads, but to enable fast twitch muscle fibers to respond quickly to exercise training loads, resulting in faster lean muscle growth”
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During blood flow restriction training, limited oxygen to the muscle means that the slow-twitch, Type I muscle fibers aren’t very active as they require oxygen as fuel. Instead, the bigger, faster Type II muscle fibers are recruited. To recruit Type II muscle fibers during traditional resistance exercises we usually need to perform exercises at very high intensity
Not only does occlusion training preferentially activate fast twitch muscle fibers, it has been shown to cause a fiber type shift from slow to fast, thus increasing the potential for muscular growth and developing explosive power.
Another possible training method is using EMS machine like a ‘Compex unit’ to fatigue certain muscles involved in the action. This may prove difficult to perform as the time taken to attach and take of the pads may prove too time consuming. However, it is a method I will experiment with. Once again, I used EMS during lunch breaks when I played and I believe in its effectiveness and I will be using it in the up and coming IPL tournament with the Rajasthan Royals.
Conclusion
I have covered many aspects of fast bowling performance in this article and hopefully started some discussion points. I will be actively testing my theories over the next month and will be open with my findings. I appreciate some of the theories in the post maybe outdated at the time of print as I know there are sports scientist far more knowledgeable than me who have differing opinions on muscle fibres. Coaches such as Dr Andy Galpin lead the way and providing outstanding research on various topic including bioenergetics.
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