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Training 101: Eccentric, Isometric & Concentric Training

9th January 2023

9th January 2023

By Adele Webb

Are you regularly trying to build muscle strength but struggling to see any improvement?

It’s a frustrating experience that most will face during strength training - especially if you want to strengthen within a stricter timeframe. It’s only natural in this situation to want to push yourself to spend more time on the same training exercises; instead of 6 deadlift reps you might choose 12, or perhaps you try an extra 20 sit-ups per session. This approach in itself however can increase your chance of workout injuries if not properly controlled and even limit your workout motivation (let’s face it, no one wants to keep doing the same workout for days on end).

In this scenario, you may be tempted to try a new and complex workout routine to keep things fresh. While a potential short-term solution, one of the best ways to smash your exercise goals is actually as simple as breaking down your current strength-building routine and focusing the training on specific eccentric, isometric, and concentric muscle exercises.

What is eccentric, isometric, and concentric exercise?

Believe it or not, during exercise the processes of strength training can be broken down into three core actions: concentric movements and eccentric movements (isotonic training), and isometric hold training.

  • Concentric movement: occurs when there’s increased tension in the muscle and therefore fibres shorten and contract.
  • Eccentric movements: are the opposite; these occur when the muscles become relaxed, tension is released, and they subsequently lengthen.

Think about the process of lifting a free weight. As you lift the weight and your arm bends upwards, that tension you feel is the concentric movement of the muscle. Similarly, as you hold but ease the weight back down your arm elongates and causes eccentric movement.

  • Isometric holding: as the name suggests. Instead of relying upon movement, you hold a single position at a particular angle to build muscle strength – think headstands and planking.

While you have likely trained using these methods interchangeably, each of the exercises has key differences and unique muscle-strengthening benefits that can make them highly beneficial within to include in a training plan.

Benefits of concentric exercises

While it might seem strange and perhaps even unnatural to focus a strength session solely on the concentric process of muscle building, there is a multitude of benefits to this type of training.

Consider the increasing tension and shortening muscle mechanism of concentric isotonic exercises.

  1. Firstly, this process causes less damage than the release of tension in your muscles (eccentric movement).
  1. Secondly, while concentric exercise doesn’t strengthen the muscle to the extent of eccentric training, these targeted workouts thankfully result in far less muscle tearing, and therefore workout recovery time can be drastically reduced.
  1. As a result, concentric exercise allows muscles to be trained more regularly, building longer endurance, power, speed, and strength levels.

While concentric exercises are a beneficial tool for any individual’s fitness goals, they are specially tailored for those looking to build their endurance. Those who will particularly benefit from this strength training are:  

  • Short-term sprinters
  • Aspiring marathon runners

Whatever muscle you are trying to strengthen, there is a range of different exercises for you. While deadlifting might be the obvious choice for those looking to strengthen their arms, most gyms also have access to bicep curl equipment that focuses entirely on training with concentric exercise. For leg day there is also similar hamstring curl and muscle-building equipment.

Those looking for concentric exercises outside the gym are also in luck. Exercises like squats and sit-ups can be a good training tool for the muscles, but even training with lifting heavy objects around the house can have a beneficial impact.      

Benefits of eccentric exercises

On the other side of isotonic training, the eccentric movement – also known as the negative - occurs when the muscle moves from a tense to a relaxed position and subsequently lengthens. Again, it might seem unusual to focus solely on the easing process of strength training, but once you’ve got the hang of it, eccentric exercise can have a wide range of benefits for your body. 

Unlike a concentric workout, the eccentric contraction process sees the muscle stretched from a larger force than the muscle is generating - think the second part of your arm or leg workout where you steadily lower the weight to its default position. You still control the weight drop, but the muscle is no longer generating more lifting force than the weight itself - hence the name ‘the negative’.

With this in mind, eccentric workouts are:

  1. A fantastic way to strengthen your muscle fibres, tendons, and ligaments and as such limit any risk of injury.
  1. Secondly the best workout to build muscle.

While yes, eccentric tailored workouts can leave your muscle initially feeling pained and lead to longer recovery times in the short term – (as I’m sure you know moving your arm can become quite the challenge after arm day) – the negative impact creates additional small microtears and lets your body repair and rebuild muscles much stronger than other workouts.

As such, eccentric-focused training is particularly useful for:

  • Athletes
  • Those looking for efficient muscle build.

I’ll agree that eccentric-focused exercises might seem a little unruly and impractical, but you will actually find there are plenty of simple ways to begin. Similarly, to concentric training, most gyms will house specifically tailored equipment based on eccentric muscle building. The triceps extension machines can be a particularly good choice for arm muscle build and likewise, calf raises can be good for the, well... calf muscles and squats are extremely effective at building a range of muscles.

Benefits of Isometric hold exercises

As the name implies, isometric holds are all about strength building from a still position. The muscle does not grow longer or shorter and instead the exercise generates muscle force and tension to keep your body in an unchanged position. While not every training plan will include isometric holds, both with isotonic exercises and as an individual fitness plan, there are multiple unique benefits of doing so that can revitalise your training.   

Indeed, isometric holds can be a fantastic method to: 

  1. Engage and build core stomach and back muscles.
  1. Improve balance and co-ordination.
  1. Build muscle and meet a difficult weight challenge once your isotonic strength exercise plateaus.
  1. Recover from injury.

Consider a bicep curl, either with free weights or using specific equipment. If you’re struggling to lift or lower a particular weight, holding the weight in a still position during the lift can strengthen your muscles and improve your ability to complete the isometric lifts during the next session. This combined isometric application is especially useful during the injury recovery process as specific muscles can be strengthened without having to shorten or elongate.

Isometric holding is probably the simplest muscle-building exercise in the sense that it’s easy to set up both in a gym or at home and doesn’t require any specific equipment to carry out. This makes hold workouts particularly useful for beginners looking to improve muscle strength. Exercises like:

  • Headstand holds
  • Wall sits
  • Hollow holds
  • Planking

can be as simple as finding a suitable wall (with a soft floor of course) and giving them a go.

Which approach is the best for strength training

Considering all the unique differences and benefits of eccentric, isometric, and concentric training you might be thinking of the best approach you should take in your exercise plan. To this point, it should be said that all 3 forms of training are just as important as one another and by focusing on one over the other you are limiting your ability to improve muscle strength.

With that said, it is important to try and get a mix of all three styles into your plan, both used interchangeably and through unique sessions set aside for each specific style. Such a training mindset will not only produce some variety in your exercise routine to keep you motivated, but by mixing these three styles, you will also train different and specific parts of the muscle to produce the best, most efficient and most effective results from strength training workouts.    

Interested to learn more about strength training? Wondering how exercise can improve your mental health?  Perhaps you have some innovative and inspirational ideas to share? Don’t hesitate to contact us over on our Instagram @liveinnermost.

 

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Products like The Greens Blend can help support daily plant intake and micronutrients, while products such as The Lean Protein fit alongside a diet that prioritises both protein and fibre, rather than one at the expense of the other. Building a high fibre diet isn’t about adding or overhauling, instead It’s about making those small adjustments that bring more consistency to your routine. Over time, those shifts tend to have the biggest impact - not just on digestion, but on how your body feels, performs, and recovers. References Renolds, A., Mann, J., Cummings, J., Winter, N., MDiet, E., Morenga, L. (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet. 393 (10170), 434-445. Click here.  NHS UK. How to get more fibre into your diet. Click here.  Hullings, A., Sinha, R., Liao, L., Freedman, N., Graubard, B., Loftfield, E. (2020). Whole grain and dietary fiber intake and risk of colorectal cancer in the NIH-AARP Diet and Health Study cohort. The American Journal of Clinical Nutrition. 112 (3), 603-612. Click here. Threapleton, D., Greenwood, D., Evans, C., Cleghorn, C., Nykjaer, C., Woodhead, C., Cade, J., Gale, C., Burley, V. (2013). Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ.347. Click here. Read more
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Digestive enzymes are specialised proteins that help break food down into smaller molecules that can be absorbed through the gut lining. Without them, even the most nutrient-dense diet would be difficult for the body to utilise effectively. The process itself is highly coordinated. Enzymes are released at different stages of digestion, working in sequence to ensure food is progressively broken down as it moves through the digestive tract. Put simply, digestive enzymes are what bridge the gap between what you eat and what your body actually gains from it. As you would expect, this can directly impact your fitness as well as your mood. Types of digestive enzymes and what they do Digestive enzymes are typically grouped into 3 core segments based on the nutrients they target. Amylase (Carbohydrates): Amylase breaks down complex carbohydrates into simpler sugars. It begins its work in the mouth and continues in the small intestine. 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A study published in the American Journal of Clinical Nutrition for example highlights that effective protein digestion and amino acid absorption play a key role in muscle repair and recovery after exercise. For anyone training regularly or focusing on performance, this becomes especially important. It’s not just about what you eat, but how well your body is able to make use of it. Where Are Digestive Enzymes Produced? Digestive enzymes are produced throughout the digestive system, with each stage contributing to the overall process. The mouth Digestion first begins with chewing. The salivary glands release amylase, an enzyme that starts breaking down carbohydrates before food is even swallowed. This early stage is often overlooked, but it plays an important role in preparing food for the next steps. The stomach The stomach next combines gastric acid with enzymes such as pepsin, which begins the breakdown of proteins. This stage is less about complete digestion and more about creating the right conditions for further processing. The pancreas The pancreas is responsible for producing the majority of digestive enzymes, including amylase, protease and lipase. These are released into the small intestine, where most digestion takes place. Clinical research has shown how central this role is. Conditions that impair pancreatic enzyme production, such as exocrine pancreatic insufficiency, can significantly reduce nutrient absorption and lead to noticeable digestive symptoms. The small intestine The small intestine completes the process. Additional enzymes help finalise digestion, allowing nutrients to pass through the intestinal wall into the bloodstream. Enzyme production across these stages can vary depending on diet, stress levels and overall gut health. This is why your digestion doesn’t always feel consistent, and some days can feel more comfortable than others. Signs your digestion may not be working optimally Some of the more common signs that digestion may not be working as efficiently include: Bloating or discomfort A feeling of heaviness, particularly after larger meals Sluggishness or dips in energy following eating Gut sensitivity to certain foods These experiences are relatively common and often reflect how digestion is responding to day-to-day habits. Below are some of the key reasons why your digestive system may not be operating effectively. Eating quickly or on the go can limit how effectively digestion begins, particularly in the mouth where enzymes first start working. Stress can also play a role. When the body is in a more alert or pressured state, digestion is not the priority, which can affect how efficiently food is broken down. Higher protein diets are increasingly common, particularly among those training regularly. While beneficial, protein requires more extensive digestion, placing greater demand on enzyme activity. Fewer whole foods and less plant diversity may influence how the digestive system responds over time. Foods high in digestive enzymes So, for those looking to improve digestion by adding more digestive enzymes to your diet, how do you go about doing it? While your body produces its own digestive enzymes, certain foods also contain naturally occurring enzymes that can support the digestive process. These tend to be most active in raw or minimally processed forms and can complement a balanced, varied diet. Some of the more commonly referenced foods include: Pineapple (Bromelain – Protease): Pineapple contains bromelain, which has been studied for its role in helping break down protein. It is often associated with supporting protein digestion. Papaya (Papain – Protease): Rich in papain, papaya is another enzyme that assists with protein breakdown. It’s frequently used in both digestive support and food preparation. Mango (Amylase – Carbohydrates): Mango contains amylase enzymes that help break down complex carbohydrates into simpler sugars, particularly as the fruit ripens. Bananas (Amylase & Maltase – Carbohydrates): Provide enzymes that support carbohydrate digestion, especially when ripe. Avocado (Lipase – Fats): Contains lipase, which plays a role in breaking down fats into fatty acids. These foods can play a useful role in supporting digestion as part of a broader diet. However, their enzyme content can vary depending on factors like ripeness, storage and preparation, and they don’t always provide consistent or targeted support on their own. In those situations, you might also look at targeted digestive enzyme supplements that can provide a more consistent and concentrated level of enzyme activity alongside meals, supporting the breakdown of proteins, carbohydrates and fats more reliably than food sources alone. Digestive enzyme supplements The key to effective digestive enzyme supplementation is choosing a well-formulated option that combines a broad range of enzymes with a clean ingredient profile. Case in point: supplements like Innermost’s The Digest Capsules are built with this in mind, offering a considered blend that fits easily into a daily routine and works alongside your existing nutrition rather than replacing it. For those considering digestive enzyme supplements, how and when they’re used can influence their effectiveness. Before or with meals Digestive enzyme supplements are typically taken just before or alongside meals, allowing them to act as food is being broken down. Around larger or harder-to-digest meals Meals that are higher in protein, fats or overall volume can place greater demand on digestion. This is often where additional supplementation can be beneficial. Fitting into your routine How and when you use digestive enzymes will depend on your routine, your diet and how your body responds. Rather than following a fixed structure, it often makes more sense to take a flexible approach. Used consistently or as needed, they should fit seamlessly into your day, supporting digestion without adding unnecessary complexity. Supporting your digestion effectively Digestive enzymes play a fundamental role in how your body processes food and accesses nutrients. When digestion is working well, the impact is often felt across energy, recovery and overall wellbeing. While your body naturally produces these enzymes, factors like diet, lifestyle and routine can influence how consistently that process runs. In those moments, small adjustments - whether through food choices or more targeted supplementation - can make a noticeable difference. For those considering supplements, a well-formulated option such as The Digest Capsules can provide a simple, reliable way to support digestion alongside your daily routine. References Leidy, H., Clifton, P., Astrup, A., Wycherley, T., Westerterp-Plantenga, M., Luscombe-March, N., Woods, S., Mattes, R. (2015). The role of protein in weight loss and maintenance. Am J Clin Nutr. 101(6). Click here.  Ni, W., Hutagalung, A., Li, S., Epstein, H. (2011). The myosin-binding UCS domain but not the Hsp90-binding TPR domain of the UNC-45 chaperone is essential for function in Caenorhabditis elegans. J Cell Sci. 124(18). Click here. Pavan, R., Jain, S., Shraddha., Kumar, A. (2012). Properties and Therapeutic Application of Bromelain: A Review. Biotechnol Res Int. Click here. Read more