Updated: Jun 27, 2022
Why not get some eccentric quasi-isometric (EQI) strength training into your fast bowlers? You might be saying that eccentrics makes sense but training using at near zero velocity contractions (quasi-isometric) doesn’t make so much sense for the fast-bowling action. Let’s back up the bus and look at the why before the how.
First what does EQI loading of muscle look like? Well, the athlete maintains a specific joint-angle against a submaximal load for as long as possible; as fatigue accumulates, an eccentric contraction commences while the athlete attempts to resist muscle lengthening maximally through the prescribed range of motion. You can see an example of an EQI in the video below.
The idea to use this type of training came from a staff member observing these Scandinavian power athletes (shot-putters and javelin throwers) using EQI training at long muscle lengths. The question then was why would athletes who require ballistic explosive type motion (like a fast bowler) engage in super slow near isometric type training. Well, the answer is in the below model (see Figure 1).
The model is a three component model and helps you understand and refine what you do, especially in the conditioning of athletes. It reminds you that there are a lot of tissues that are responsible for force production and transmission. The CC stands for the contractile component, which is your muscle fibres and myofilaments. The SEC is your series elastic component, which refers to your tendon and aponeurosis. The PEC is the parallel elastic component, which includes tissues such as your mysial tissues e.g. endo-, peri- and epimysium. You can see all the different components in the picture of muscle – Figure 2.
So all these components have important parts to play in force expression depending on the type of contraction, velocity and amplitude of movement. You will note that the SEC and PEC are modelled as springs (in figure 1) because they have very important parts to play in the storage and utilisation of elastic energy – sling shot effects.
In this blog I’d like to focus on the PEC (also known as intramuscular fascia) and the link to EQI and how we can get more out of this tissue to enhance the force and power outputs of fast bowlers. There is a stack of this connective tissue (PEC) in muscle, in fact up to 35% of muscle mass can be this type of tissue. You get a sense of the amount of this tissue when you see Figure 3 which has had the muscles stripped out via acid digestion to leave the endomysial and perimysial framework in place. Can this tissue (mainly collagen) adapt to training? Sure can! We can change the quantity and quality of collagen, to get muscles stronger without increasing the size of muscle (hypertrophy).This is called increasing the specific tension of muscle.
Now the how. Guess what type of training is great at increasing the quality and quantity of the PEC? You guessed it – EQI is great for producing collagenous adaptation. The mysial tissues need to be stretched past resting length before they begin contributing to force output. As muscles move to longer lengths the actual fibres get weaker, however, the contribution of the PEC becomes greater and provides stability to the muscle fibre at longer lengths. Note to self, injury prevention as well as performance enhancement benefits. So, to train the PEC we need to place stress (load) and strain (length) on the connective tissues. So taking a muscle group to a long muscle length and then holding it as long as possible and then as fatigue accumulates the lengthening eccentric contraction occurs (EQI), is great for placing stress and additional strain as the muscle slowly lengthens.
If the correct stress and strain are provided to the muscle then these are some of the likely adaptations. The quantity of the connective is likely to increase, the tissues becoming larger and stronger and this usually happens in tandem with cross sectional changes in muscle, after a time lag. Also the quality of the connective tissue can change whereby the tensile strength per unit area of connective tissue is increased. Furthermore, this change in quality can increase stiffness which in turn can positively affect visco-elasticity and force transmission. These adaptations will result in enhanced force-length and force-velocity relationships which is all great for your fast bowlers.
There are other claims made from practitioners as to the benefits of EQI, namely:
Increased muscle size when added to RT programmes
Increased strength throughout full ROM
Improved torque, joint stabilisation, proprioception, and movement efficiency
Improved parallel and series elastic components
Improved inter- and intra-muscle control
Enhanced muscle stiffness with lower fatigue levels
Enhanced capacity to contract a muscle when it is in stretch
Stronger tendons, heals tendonitis
Enhanced IGF-1 signalling
So my advice then is to get out and try some EQI and here are some basic loading parameters:
EQI: ‘Lower till you feel a stretch, hold, fatigue, lengthen’
Load: <70% 1RM, most <50% 1RM
Length of stretch: 3-5 min broken into sets 60-90 sec each (beginner 45 sec for 1 set)
Increase load if you can hold for 90+ sec without lengthening
Do after target muscles have been trained for hypertrophy
OR before a session if a lack of mobility precludes a movement
Rest: 60 sec between sets
Next step – identify those muscle groups and therefore exercises that will benefit most from EQI training of your fast bowlers, and integrate EQI into your normal training to touch base with your connective tissues to better effect, and enhance the sling shot effect in your bowlers. I am also betting it will have some injury resistance value also. If you want to take a deeper dive into connective tissue training then head to my website where I have a free Masterclass on training the PEC (https://www.professorjohncronin.com/#freestuff ). Also you can find a lot more on EQI training in the Research in Action part of the website.
Acknowledgement: Dr. Andre Nelson from Victoria University provided some of the material for this blog and needs to be acknowledged for his contribution.