Q: What is eccentric contraction and why is it important to include in your training?
A: There are actually three types of contractions: isometric, isotonic and isokinetic. Most people in the fitness industry are familiar with isometric and isotonic contractions.
An isometric contraction is when the muscle contracts but the length of the muscle doesn’t change.
An isotonic contraction causes the length of the muscle to change and is further broken down into either a concentric contraction or an eccentric contraction.
- A concentric contraction is when the muscle contracts and shortens
- An eccentric contraction is when the muscle contracts and lengthens
Most people are very good at creating a concentric contraction, but have a more difficult time with the eccentric one. The eccentric phase requires muscular control. If we use the example of a bicep curl, it’s easy for people to connect to their anterior arm muscles to flex their elbow, but often they lack the control of returning to elbow extension.
Q: Why is it so important to maintain control in the eccentric phase of a movement?
A: Simply put, to ensure greater all-around muscle strength to enjoy prolonged activity and avoid injury! Some great strengthening tools to use would be our Resistance Loop, Flex-Band Loops or Flex-Band. You can also work on eccentric control using spring tension.
Those fitness accessories are often used in Merrithew™ programming as each one is flexible and offers the stretch and recoil function. This is key to providing feedback to the muscle, especially on the eccentric phase, to say, ‘Hey muscle, you need to still work to control the recoil back to the starting length’. Handweights or Toning Balls do not have the same effect except when paired with proper cueing, technique and control.
As an instructor, I am constantly making sure my clients are controlling their movements as this is often the phase where injuries occur. This is also the phase where optimal muscle strength is achieved and my clients are most challenged both mentally and physically. I’ve seen the biggest changes in a client’s strength and stability when focus is placed on both contractions.