KET Fitness

To answer this question we must examine the different muscle contractions.

When we move a weight up and down, as in arm curls, there are 2 types of muscle contractions – Concentric Contraction(Cc) and Eccentric Contraction(Ec).

The Cc occurs when we lift the weight. During this phase of muscular contraction there is shortening of the muscle with an increase in muscular force. When we lower the weight the phase of contraction known as the Ec occurs. During this phase there is a greater force generated in the muscle and a lengthening of the muscle.

It is the Ec phase of the contraction that prevents the weight from being dropped or prevents us from falling down the steps or a hill. It is the lengthening with the muscle force that causes greater soreness following exercise.

Let’s look at running on a treadmill with no grade. During this session there is not much Ec occurring. Now compare that to running down a hill outside. During this type of movement there is much “braking” or Ec occurring in the quads and if we’re not conditioned for it (doing downhills frequently) the next day we will have greater soreness versus the treadmill session.

If we look at triathlon training there is not a whole lot of Ec occurring during the swim and the bike but there is during the run when going down hill.

The take home message: During training spend time with Eccentric Contractions. However, remember there is a greater risk for injury if we do too much of one type of training. So, always vary the training. Use flat treadmill training one day and outside rolling hills another day.

Examples:

• Running hill repeats (using negative grades on a treadmill if it has that capability)
• During wt training lowering the weight slowly (emphasis on the “negative” phase of contraction)
• Using a stability ball can help as well

-Mark