Updated: May 25, 2020
Contents of this article:
The Force/Velocity Relationship
In this article I will talk about the application of the different muscle contraction types in your own training and why you may want to implement a variety of contraction types in your training. I will touch on the force-velocity relationship briefly, as I will have a separate article going in to more depth on this topic. I will try to keep the science as easy going as possible, but if you're unsure on any of the points I cover in this post, drop us a message on our social media and I'll help with the explanation.
The sliding filament theory is used to explain how muscle contractions occur, so be sure to go read up on that as I'm not going to ramble on about that. We have three types of muscle contractions. Eccentric Contractions occur whilst the muscle is lengthening under tension. An example of this would be a Romanian Deadlift, which target the hamstrings eccentrically. An Isometric Contraction is when there is no change in muscle length during contraction i.e. pushing or pulling an immovable object. Lastly, the most common is a Concentric Contraction, these types of contractions results in flexion and extension at the joints. For example a bicep curl, the biceps contract and cause flexion at the elbow.
The Force/Velocity Relationship
The force/velocity relationship refers to the changes in velocity (speed) when there is an increase or decrease in force (load). The best way to explain this is through a diagram (see below). As you can see as the force is increased the velocity of the movement decreases, or as the force is reduced the velocity of the movement is higher.
We can use the force/velocity curve to help programme our training for specific performance gains. For example, if an individual wanted to solely increase their maximum strength, they would look to lift loads that generate high amounts of force, but will generate low velocity of contraction (>85% 1RM).
So where does the different types of muscle contractions come into all of this? Well, below is another force velocity curve but this time it has each of the muscle contractions along the bottom axis. As you can see eccentric contractions generate the highest amounts of force but in negative velocities (performed during muscle lengthening) Isometric contractions generate high amounts of force but when velocity is 0 (no change in muscle length), and concentric contractions contract at the highest velocities but generate the lowest amounts of force.
Application to Training - Eccentric
We now know that eccentric contractions generate the greatest of forces at high negative velocities but why would this benefit us in our training ?
In sport a high proportion of muscle strain injuries occur during these eccentric contraction e.g. decelerations, landings and late-swing phase during high-speed running. If we train with these eccentric contractions at high loads this will in turn help reduce the risk of injuries during match-play. There is tonnes of scientific literature out there on the use of Nordic hamstring curls (eccentric hamstring exercise) and their use in reducing hamstring injury risk in football.
Another use for eccentric contractions is for muscle hypertrophy and strength improvements. Again due to the highest forces being generated here, short term muscle damage is increased from performing these exercises. However, by programming these exercises in a low-dose at high loads it can significantly improve your strength and hypertrophy gains. For example, by programming negative bench press (obviously with a spotter) controlling the descent at loads greater than your 1 rep max, this can help break through plateaus in your training (expect to be sore the days after performing these).
Examples - RDL, Nordic Hamstring Curls, 'Negative' Exercises,
Application to Training - Isometric
The great thing about isometric contractions is there high force generating capacities with no change in muscle length. Similar to the eccentrics, maximum isometric press or holds can be a good way to push through training plateaus as you can use loads greater than your 1 repetition maximum. Another, benefit to using isometrics is that there will be less delayed onset muscle soreness (DOMS) due the muscle fibres remaining the same length throughout the contraction.
In relation to injury rehabilitation, partial isometrics (50-60% maximum) can be a great way to slowly rebuild strength of the injured limb due to the reduced risk of re-injury as the muscle fiber remains the same length throughout the contraction.
Examples - Isometric Bench Press, Isometric Squat (perform at 'sticking point'), Iso-mid thigh pull.
Application to Training - Concentric
The most common type of muscle contraction, causes flexion and extension of the joints. One consideration here, is that if the only exercises you do in the gym are concentric exercises this can result in a muscle length being reduced in-turn reducing your flexibility. That is why its essential to use all 3 types of muscle contractions in your training. A good way to ensure this is by training with compound exercises (Squats, Deadlifts, Pull Ups, Bench Press) as these exercises have each type of muscle contraction at different points in the movement.
However, concentric exercises are good if you are training frequently as they lead to the least muscle soreness (DOMS) in the days following training. Therefore, if you're going through a phase of training in which training volume is very high, you may want to consider having a high proportion of your exercises be concentric exercises to reduce DOMS. Although most exercises you do will have an eccentric element (during descent), there are ways to perform solely concentric exercises, for example Trap-bar Deadlift and drop the weight at the top of the movement eliminates the eccentric contraction.
Examples - Leg Curl (hamstrings), Leg Extension (Quads), Bicep Curl (biceps), Tricep Extension (triceps).
Make sure you are training using a variety of exercises that include each type of muscle contraction. Keep in mind the force/velocity relationship if you are training for specific performance benefits i.e. low-loads high-velocity for maximum speed and high-load low-velocity for maximum strength. Need help programming your training, get in touch with us, we are happy to help.