Eccentric Loading for Greater Hypertrophy, Strength and Power

By Gareth Sapstead BSc (Hons)
Gareth is a strength coach and fitness specialist studying for his masters (MSc) in strength and conditioning.
(July 2010)

Here at MuscleTalk, readers and contributors pride themselves on their knowledge on everything to do with building muscle, getting stronger and more powerful, and building impressive physiques. This is why I thought I would write an article about a subject that can help the typical trainee to achieve all of these goals and, in my opinion, it is overlooked far too often in a lot of training programmes.

Anyone who has been involved in the iron game for a period of time will have heard of an eccentric muscle contraction. If you haven't then you need to go away and start reading now, because you're missing out! For example, during the standing biceps curl exercise, after lifting the bar (also known as the concentric phase) the bar is then lowered during what is referred to as the eccentric or negative phase of the lift, whilst using eccentric muscle action. Now, an eccentric muscle contraction has a few 'special' properties that make it different from a concentric contraction. These properties include a 40-50% higher force production capability, lower motor unit recruitment although higher stress placed upon each individual motor unit (referred to as a tetanus), increased micro-trauma and DOMS (Delayed Onset Muscle Soreness) from training when using augmented/accentuated eccentric contractions, as well as eccentric contractions having the ability to recruit a greater number of high threshold motor units than concentric training alone (2). With all of these clear advantages associated with the use of eccentric training, why is it I still often see people in the weights room who are not controlling the speed of their repetitions, specifically the eccentric portion? You know who you are! By manipulating the eccentric phase of the lift by adding either additional (controlled) weight to it, or by slowing down the eccentric tempo, trainees can experience superior results in both their athletic performance and their physique over more 'traditional' training modalities.

Manipulating eccentric stress for strength and power
It has been some time since scientists have known that the eccentric phase of an exercise is responsible for more strength gains than the concentric phase alone. A study by Hortobagyi et al (1996) found that the total maximal strength improvement from eccentric-only training over a 6 week period showed a mean improvement of 85%, while concentric-only training led to an improvement of 78%, where increases in isometric, concentric and eccentric strength were combined (5). Interestingly however, the researchers used sub-maximal eccentric actions and maximal concentric actions, which surely tell us that greater improvements in strength may be seen when performing eccentric actions that are closer to maximal eccentric strength levels. Another study conducted by Higbie et al (1996) also found greater combined strength increases with eccentric-only training compared to concentric-only; 43% compared to a 31% increase in strength over 10 weeks (4). A more recent study concluded that 'an accentuated eccentric load evokes acute increases in vertical jump height, as well as in the kinetic and kinematic variables that are considered important to vertical jumping ability' (6). In another words by preceding a non-loaded vertical jump with a vertical jump using an additional eccentric load, greater force, velocity and power (and therefore jump height) may be observed.

Manipulating eccentric stress for enhanced hypertrophy
In one of the above aforementioned studies it was concluded that an eccentric-only training programme resulted in a 6.6% gain in lean muscle mass over 10 weeks, compared to the concentric-only group who gained an average of 5% over the same period of time (4). Although a difference of 1.6% does not seem that much over a 10 week period, any serious bodybuilder knows that a 1.6% difference would lead to a significant visual effect. In another study that looked at upper arm thickness with eccentric-only compared to concentric-only training for 8 weeks, subjects gained an average of 13% in upper arm size in the eccentric-only group, compared to around 2.5% in the concentric-only group when performing repetitions at the same speed (3), therefore eccentric training may result in a bigger set of 'guns' over traditional, uncontrolled eccentric training. There is also some evidence that suggests that eccentric training results in a shift in muscle fibre type to a more fast twitch profile; the type of muscle fibres that are more susceptible to hypertrophy. Therefore not only will eccentric training result in greater hypertrophy in the short term, but as your muscle fibres take on a more fast twitch profile you will actually find it easier to gain size with any training you do.

Practical applications

Eccentric training for strength and power
In my opinion the best way to use this information to achieve gains in strength and power is with the use of augmented eccentric loading (AEL). I have personally written and presented research on this subject, and firmly believe it is the future of strength and power training. AEL incorporates the use of greater eccentric loads followed immediately by a lighter concentric load. This can be done through the use of weight releasers or through manual resistance (have a training partner press down on the bar during the eccentric phase and then release just prior to the concentric phase of each repetition). There is also one other way in which AEL may be performed, and with ordinary gym equipment, however the set-up is more complex and additional spotters are required (see Watkins 2010 for details of the set-up).

AEL has been shown in numerous studies to be an effective training tool to enhance strength and power in both the upper and lower body, with one study demonstrating an acute increase in bench press one repetition maximum strength from 97.44 kg to 100.57kg when testing was preceded by AEL (1). Greater adaptations may be observed when the eccentric load is approximately 20% greater than the concentric load (7); however the method may not be as effective on novice lifters, with some studies showing limited effect with these individuals (8).

An 'upper body' training programme for strength development that incorporates the use of AEL would look like:

A1) AEL Bench Press 4 x 5/1*, at 87%1RM (concentric load) 105%1RM (eccentric load), 75 seconds rest (superset with A2)

A2) Bent-Over Barbell Row 4 x 5/1*, at 87%1RM concentric 105%1RM eccentric, 150-180 seconds rest

B1) Military Press 4 x 6, at 83-85%1RM, 75 seconds rest (superset with B2)

B2) Wide-grip Pronated Pull-ups 4 x 6, at 83-85%1RM, 150-180 seconds rest

*A cluster set configuration works best for AEL, so 5/1 means: 1 repetition followed by 5-10 seconds rest for a total of 5 repetitions, then go straight to the second exercise in the superset. If using weight releasers, have a training partner reset them after each repetition, or have them apply a controlled manual resistance by pressing down on the bar only during the negative/eccentric phase of each repetition.

Eccentric training for muscle mass
In my opinion there are two ways in which to achieve this: 1) you can slow down your eccentric tempo which would increase your eccentric time under tension. I like to have two week long periods of training by alternating two weeks of 3-4 second eccentrics followed by two weeks of 8-10 second 'super slow' eccentrics whilst using the same exercises. 2) The second method I like to use for this purpose is called the '2/1 method'; quite simply lift the weight using both limbs and then allow only one limb to lower the weight (This technique is quite similar to a well known training method among bodybuilders called 'negatives'). Using the hamstring curl as an example, you would curl the weight up using both legs then allow only one leg to lower the weight, alternating sides used to eccentrically lower the weight during each repetition. Select a weight that is 5-20% greater than your concentric maximum for that number of repetitions, and stick to no more than 6-8 repetitions for 4-5 sets using a functional hypertrophy protocol.

A sample 'upper arm' training programme incorporating the use of controlled/accentuated eccentric tempo for muscle mass would look like:

A1) Close Grip (10 inch) Bench press, 4 x 6-8, on a 40X0 tempo**, 10 seconds rest (superset with A2)

A2) 1-Arm Preacher Curl, 4 x 6-8, on a 4010 tempo**, 90 seconds rest

B1) Triceps Dips, 4 x 8, on a 3210 tempo**, 10 seconds rest (superset with B2)

B2) Incline Dumbbell Curls, 4 x 10, on a 3020 tempo**, 60 seconds rest

C1) Decline Dumbbell Triceps Extensions, 3 x 12, on a 4010 tempo**, 10 seconds rest (superset with C2)

C2) Neutral Grip Rope Hammer Curls, 3 x 12, on a 40X1 tempo**, 60 seconds rest

**Tempo refers to speed of contraction: 4010 means a 4 second eccentric, 0 second pause at the bottom of each rep/ end of the eccentric phase, 1 second concentric, and 0 second pause at the top of each rep/ end of the concentric phase. 'X' means an explosive contraction.

Conclusion
There are clear benefits to changing your eccentric load or tempo (or both), so go out and apply some of these techniques talked about in this article to your current training, and allow your physique and strength to reach the next level of development.


References:
  1. Doan, B., Fry, A., Korziris, L., Kraemer, W., Marsit, J., Newton, R & Triplett-McBride, N (2002). Effects of increased eccentric loading on bench press 1RM. Journal of Strength & Conditioning Research. 16(1): 9–13.
  2. Enoka, R (1996). Eccentric contractions require unique activation strategies by the nervous system. Journal of Applied Physiology. 81: 2339-2346.
  3. Farthing, J & Chilibeck, P (2003). The effects of eccentric and concentric training at different velocities on muscle hypertrophy. European Journal of Applied Physiology. 89: 578–586.
  4. Higbie, E., Cureton, K., Warren, G & Prior, B (1996). Effects of concentric and eccentric training on muscle strength, cross-sectional area, and neural activation. Journal of Applied Physiology. 81: 2173-2181.
  5. Hortobágyi, T., Barrier, J., Beard, D., Braspennincx, J., Koens, P., Devita, P., Dempsey, L & Lambert, J (1996). Greater initial adaptations to sub maximal muscle lengthening than maximal shortening. Journal of Applied Physiology. 81: 1677-1682.
  6. Sheppard, J., Newton, R & McGuigan, M (2007). The Effect of Accentuated Eccentric Load on Jump Kinetics in High-Performance Volleyball Players. International Journal of Sports Science & Coaching. 2(3): 267-273.
  7. Watkins, P. H (2010). Augmented Eccentric Loading: Theoretical and Practical Applications for the Strength and Conditioning Professional. Professional Strength and Conditioning, UKSCA Issue 17, 4-12.
  8. Watkins, P.H and Sapstead, G (2010). Augmented eccentric loading and force and power production during vertical jumping. Research poster presentation at the UKSCA Annual Conference, Kents Hill Park Training and Conference Centre, Milton Keynes, UK.