Eccentric training might be the single greatest training method that often people neglect. It’s almost infuriating sometimes seeing people train because they are leaving so much progress on the table. Most people simply focus on lifting the weight and almost never focus on the eccentric action (muscle lengthening). By doing that, they are neglecting a component of a repetition that can have such a high return in terms of strength and muscle mass. Don’t just take my word for it. Dorian Yates, one of the greatest bodybuilders of all time and the first “mass monster”, advocated for the use of focusing on the eccentric or negative. The only problem is that training the eccentric does force you to decrease the loads (at the start) and people don’t want to do that. Their ego gets in the way or it’s not as cool for social media.
If you want to limit how big and strong you can get or shorten your lifting lifespan, don’t bother reading the rest of the article. But if you want to make serious improvements in strength and size AND stay healthy so you can lift injury-free and make progress for a long time, continue reading so you understand why you NEED to start including eccentric training.
Greater Force Per Motor Unit/Muscle Fiber
Contrary to what many believe (including myself), during the eccentric action of a movement, there are actually FEWER motor units (a motor neuron activating many muscle fibers) activated, however, the force or load placed on the body is the same. This means that the force/motor unit or muscle fiber is GREATER during the eccentric portion than the concentric portion.
Let me give an example to clarify this because it is one of the foundational reasons as to why eccentric training is beneficial.
Let’s say you’re doing DB Bicep Curls with 25lbs in each arm and on the concentric, you have 100 muscle fibers activated by 20 motor units (the numbers were chosen simply to make it easier to demonstrate). As I mentioned earlier, there are less motor units (and therefore muscle fibers) activated on the eccentric portion. Considering this, there may be only 10 motor units activated (50 muscle fibers) on the eccentric. HOWEVER, the weight you are using for the curls has not changed between the concentric and eccentric portions, meaning the 25lbs is now loading only 50 muscle fibers. This is a much greater load or mechanical tension placed on the individual muscle fibers, creating a strong growth and hypertrophy stimulus.
Concentric | Eccentric |
20 motor units = 100 muscle fibers 25lbs Dumbbells 25lbs/100 muscle fibers = 0.25lbs/muscle fiber | 10 motor units = 50 muscle fibers 25lbs Dumbbells 25lbs/50 muscle fibers = 0.5lbs/muscle fiber |
*The numbers were simply chose to make the example easier to calculate. There is not necessarily a 50% reduction in motor unit recruitment during the eccentric action, meaning the load per muscle fiber during the eccentric is not necessarily twice that of the load during the concentric.
Greater mechanical tension per muscle fiber = Greater stimulus for hypertrophy and strength.
2. Fast Twitch Muscle Fiber Recruitment
Eccentric training preferentially recruits the higher threshold Type 2b (Fast Twitch) muscle fibers. These fibers are activated when the loads or tension are high, which makes sense if you think back to the previous point about greater tension per motor unit on the eccentric portion.
The Type 2b fibers are responsible for producing high levels of force at fast rates (power). Therefore, preferential activation and training of these fibers will result in a transfer into strength gains. Along with the improvements in strength, these fibers have a greater potential for muscle hypertrophy (or more specifically, myofibrillar hypertrophy, aka, “functional hypertrophy). The hypertrophy of these fibers results in an increase in the cross-sectional area (size) of the muscles and increased contractile elements, both contributing to increases in strength and power.
Fast twitch muscle fiber recruitment = Greater hypertrophy & strength gains
3. Increased "Strength Potential"
In theory, we should be roughly 20% stronger eccentrically compared to our maximal concentric strength. However, for someone with less training experience, this percentage is much lower and there may actually be no significant difference between their concentric and eccentric strength. When someone starts to train, they get stronger primarily through an increase in muscle mass and improved motor coordination (they learn how to do the movement). What happens after a bit of time? They hit a plateau.
Why? Most of the time, they’ve neglected improving their eccentric strength and have reached their current “strength potential”.
Strength Potential is what I refer to as their strength ceiling, but isn’t necessarily what they can do at that very moment. As I mentioned earlier, we should be approximately 20% stronger eccentrically than we are concentrically, meaning we should be able to lower under control 120% of our 1RM. I view this as 20% of room for GROWTH! Once you have that gap established, the goal with training is to bring yourself closer to that ceiling so that you can eventually reach that load. If you don’t have that 20% gap and you’re already at the ceiling, you have no room to get stronger. Your body will LITERALLY shut you down and inhibit you from getting stronger.
Within our tendons, we have something called the Golgi Tendon Organ (GTO) which receives signals about how much tension is placed on the muscle. If the signal is too strong, the GTO signals this to the nervous system and receives an inhibitory (shut down) signal back to shut down producing anymore force. By training the eccentric portion, you are desensitizing the GTO, meaning you are quieting down the signals so that it doesn’t tell the nervous system that you’re in danger and allows you to produce the required force to lift the weight.
“You can’t produce what you can’t absorb” – Christian Thibaudeau
4. Reduced Risk of Injury
Muscles are typically strongest in the middle range of their length and weaker when long and short. By utilizing eccentric training under load, you are essentially increasing muscular length (eccentric refers to the lengthening of muscles) AND, because there is a load and tension placed on the tissue, you are building strength in the lengthened range. This is critical because many injuries occur when a muscle is loaded in its lengthened position (ex. Bottom of a bench press and blowing your pec out).
Eccentrics are also a valuable tool for improving tendon thickness and joint health. Many athletes that report with tendinopathies benefit greatly from eccentric work. Tendon thickness can help strengthen the joint and prevent potential tendon injuries, however, it can also help with performance as the tendon has improved capacity to store elastic energy during eccentric actions. The elastic energy absorbed during the lowering phase can then be released and utilized to produce force. Think of it as thickening a rubber band – A thicker band when stretched will be more powerful than a thinner band.
Improved tendon health + Increased muscle strength when lengthened = Decreased risk of injury
5. Manipulate Training Intensity (Percentage of 1RM)
The last reason why including eccentrics into your training is important is to manipulate the intensity or load you are using. Like I mentioned at the start, many people don’t enjoy slowing down the eccentric because it forces them to use lighter weight and that’s not good for social media or their egos.
I get it. I don’t enjoy training light either. But we can’t train at or above 90% of our PRs all the time. You will burn yourself out, or worse, get hurt. You need to spend some periods in lower intensity ranges to manage recovery and give your joints a break from the heavy poundage. To lower the intensity (ex. Work in the 65-75% range), we typically need to do a lot of repetitions for the training to be hard. High rep sets suck…Nobody likes them.
What if I said you could still train in the lower rep ranges (ex. 1-5 for strength, 6-10 for hypertrophy) without risking injury or burn out?
Simply by slowing the eccentric down, you are reducing the weight by 10-20%, thus managing the stress and abuse placed on the body. For example, in my last strength cycle, my first block included 5-second eccentrics on the main lifts for 3-5 repetitions as my max effort work. On average, my weights were 20% lighter than the estimated percentage, but the training was still hard. If I had just started with true/no tempo triples and sets of five, the intensity would have been too high for the start of the cycle and I would’ve been screwed next block, or the training would’ve sucked because it felt easy.
Estimated % | Actual % | Difference | |
5 repetitions | 86% | Squat - 67% Bench - 64% | Squat - 19% Bench - 22% |
4 repetitions | 89% | Squat - 69% Bench - 68% | Squat - 20% Bench - 21% |
3 repetitions | 92% | Squat - 74% Bench - 73% | Squat - 18% Bench - 19% |
AVERAGE | Squat - 19% Bench - 20% |
This data comes the data I collected over my last strength cycle.
What these numbers show me is that, by manipulating the tempo or including eccentrics, I am able to still get a strong training stimulus using lower reps while managing recovery and loading.
Use eccentrics to manipulate intensity without changing the rep scheme.
If getting jacked, strong, and healthier aren’t enough reasons to include eccentrics into your training, good luck to you!
Train hard folks.
Coach Max
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