Concentric training is best described as ‘the shortening of a target muscle whilst under contraction’. Put simply, the muscle fibres shorten whilst contracting allowing a load to be lifted. In the example of a bicep curl, this would be the upward phase of the movement.
Conversely, eccentric training is the opposite and is best described as ‘the lengthening of a target muscle whilst under contraction’. This time, the muscle fibres lengthen whilst contracting allowing a load to be lowered. In the example of a bicep curl, this would be the downward phase of the movement. Eccentric muscle action allows the load to be returned to the start position in a controlled manner and can be achieved during all exercises, regardless of whether body weight, free weight or machine weights are selected.
Many gym users tend to focus intently during the concentric phase of an exercise to achieve the initial shifting of a load, but seem reluctant to apply the same effort during the eccentric phase. Although at this point there may be some generalisations on my behalf, it is common to observe individuals becoming lazy during the eccentric, lowering phase of an exercise and this becomes clearly evident when the load is quickly returned to the start position without any or very little control. The purpose of this article is to highlight the potential benefits of eccentric training and to allow you the opportunity to apply these principles to your training regimes.
Previous research comparing the effectiveness of two training programmes; Concentric only versus a combination of both concentric and eccentric training, demonstrated that the group undertaking both concentric and eccentric training achieved greatest gains in strength and strength related exercises. These findings have been replicated in numerous studies. From a practical viewpoint, it is apparent that the eccentric phase is important in bringing about further enhancements in strength gains.
Research has also independently compared concentric and eccentric movements with similar results being found in favour of the eccentric training. These significant benefits included the following:
Again, from a practical viewpoint, it is apparent that the eccentric phase can bring about significantly greater gains in both muscular strength and size when compared to its eccentric only equivalent.
So how can you apply these eccentric principles to your training to enable greater results? This question to some extent is determined on how you wish to focus your training. One option is to place greater emphasis on the eccentric phase of all exercises you perform. For example, rather than just allowing the load to lower quickly when completing bicep curls, make a conscious effort to lower the load in a controlled manner. One common method to achieve this is to complete the eccentric phase to a four second count for each repetition.
A second option is to alter your training to include eccentric only exercises. However, this training method will require a second person to act as a spotter. It would be the responsibility of the spotter to take the majority of the load during the concentric phase and allow you to only apply effort during the eccentric phase. It is hypothesised that you can increase your load by approximately 40% when switching from concentric to eccentric movements so this will provide a good estimate for selecting an appropriate load. Remember however, the key to eccentric training is to lower the load in a controlled manner so if you are not able to do this then consider a reduction in the load utilised.
Before signing off there is one final important consideration factor. Eccentric training causes greater microtrauma to the target muscle than its concentric equivalent so expect to feel fatigued and sore for greater periods than previously experienced. Consequently, you may have to include more rest days into your training or alter your sessions to focus on specific muscle groups so that this factor does not become an issue.
As stated above, the intensity of eccentric training can create enhanced levels of fatigue and soreness in the target muscle than previously experienced through other training methods. During rest days it is worthwhile considering the following supplementation to assist a full recovery in preparation for your next session;