When you talk about strength training many people have the image of a powerlifter or Olympic Weight Lifter heaving heavy weights overhead. However this is not necessarily the truth of pure strength or even functional strength. I often talk about dispelling the myth of size = power. The buffest body does not make the strongest body. And it definetly doesn’t make the fittest and most able body. When you have range of motion and power you need the strength to be able to not only utilise that power but also to CONTROL it.
So how do we get this strength. As with all things that are worthy of gaining - it takes hard work and commitment. And that means training it. Yes, that’s a committed purposeful long term program of recruiting and training in the right way to gain a desired and habitual result.
So if you are looking at recruiting strength and not just size, then you need to do more than lift heavy things and put them back down again. In fact, it’s the putting them down part that is actually more to the point. Eccentric loading is asking a muscle fibre to lengthen under load. Essentially the amount of force produced when a muscle lengthens. Concentric contraction is the active phase of lifting a weight or performing a movement where the muscle fibres are shortening. Think Bicep Curl, the biceps brachii is concentrically contracting whereas the descend of the movement is asking the biceps to lengthen as it lowers the weight.
Research has shown that eccentric training generates 1.3 times more tension than concentric contractions. This fact alone means that eccentric training can be more effective at creating tension in a muscle which creates a more beneficial strengthening of these muscles in an action. So to create or generate more strength in a motion or action, say a chin up - you would be wise to invest your time in the descending action to create more strength that you can utilise in the concentric or upward motion of the movement.
Research also shows that eccentric training improves power by altering force and time elements within a movement. Eccentric training creates more force as it is more energy efficient in its molecular construction or contraction. The myofilament cross bridges are essentially like little teeth that in a concentric contraction, bite together to shorten a muscle fibre. In an eccentric contraction these teeth elongate the muscle fibre via a catch-release.
It is far more efficient as the number of cross bridges utilised and ATP or molecules of energy used is less. Thus you can control a heavier load on the descend than you may be able to lift on the ascend. There is more mechanical load per unit of muscle fibre in an eccentric contraction rather than a concentric contraction. Hence you could lift 100kg in a one rep maximum lift (maximal load) and be able to control 125kg on the descend without having to lift it up.
Eccentric training stimuli can be used periodically to improve or maintain the neuromuscular system’s ability to generate fast force production.
The benefit of these technical elements is that
Timing is often all important in utilising eccentric movements. Essentially you want to be performing eccentric movements slower than you perform the concentric. Ideally you want to be able to set a time frame for your eccentric loadings and be able to stick to it. When you start sacrificing your time frames for speed, you are perhaps not tapping into the true essence of control and time under tension loading that is the advantage of the eccentric system. When you ‘bounce’ out of the bottom of a movement, you are utilising soft tissues (tendons) and connective tissues to absorb some of the muscular function. Like two ends of a cord snapping together, this dissipates the load that is being generated by the muscles. When you control the movement and even spend a moment in the lengthened state (end Range of motion) you recruit the muscle fibres solely to generate the force of the action. So in essence, at the bottom of the eccentric contraction IF you are going to perform the concentric phase, it is important to spend a moment in the lengthened phase to eliminate elastic recoil and not be relying on connective tissues to perform in the movement.
Eccentric is vital not just for generating movement but more-so for controlling it and this has a huge impact on control and longevity for an athlete as it has huge benefits for absorbing impact and forces that are generated on the body. In a landing phase from a jump for example, eccentric contractions are the most valuable component of the landing as they help to absorb the impact of coming down from a high elevation. For someone like a basketball player, figure skater or gymnast, this component is vital for body longevity. If the eccentric muscles are not strong enough the impact of the landing goes directly to the joints and anyone over 30 knows that you don’t want that. Articular Cartilage has a finite life and you want to hold onto that for as long as you can - so work your eccentric control.
Andrew Heffernan writest that “slower eccentric contractions cause minimal stress to connective tissues, emphasizing pure strength and hypertrophy in the muscles. Faster eccentric contractions, which activate the stretch-shortening cycle, help build resilience in connective tissues and promote explosive strength, agility and general athleticism”. SO it isnt just the slow descending movements and slow timed lowering of actions that can be utilised in eccentric training. Plyometrics is a form of fast twitch eccentric loading that can be utilised to create more strength and influence power in a movement. It also helps to create a high degree of muscle fibre damage which ultimately leads to positive muscular development as the muscles adapt and create development not only in fibre damage but can also in positive hypertrophy. Creating size is a by-product of creating greater force or power that can come from eccentric training.
Eccentric training is actually used by the doyens of bodybuilding as well as a tool to break through plateaus of training regimes. It has been stated that due to the fatiguing nature of exercise which is where hypertrophy (building muscle size or fibres) occurs, eccentric loading actually fatigues muscles quicker and therefore can create better or increased hypertrophy. It can also be a way of shocking your muscles into a great lifting capacity as you can lift more weight in an eccentric contraction than you may be able to do in a concentric lift. Some bodybuilding trainers actually co-ordinate fast twitch eccentrics with maximal lifting loads to create greater tension and muscle fatigue that leads to hypertrophy of the high threshold fast twitch type IIb Fibres
SO utilising eccentric training and even spending one or two of your workouts on your eccentric loading can be of great benefit to your body and your longevity. If you want to improve a movement or the ability to perform a movement, sometimes slowing it down and working with a regressed concept (breaking down the movement to it’s eccentric part) can benefit in building more power or bettering the technique. So think about implementing it into your routine as a way to shake things up or to better improve that which you are trying to perfect.