Stretch Reflex – Follow up

My friend, Moses, posted a link to this New York Times article in the comments of my last Stretch Reflex post. It has really good information about the myth of stretching before exercise. To sum it up, static stretching (holding a stretch for 30 seconds or longer) temporarily weakens muscle tissue which is not what you want before a good workout. The article suggested it could impair performance by up to 30%!

Currently, the new ideas behind stretching are to perform dynamic stretches before exercise. These are active stretches that prepare you for the type of activity you are about to perform. This could include windmilling your arms, kicking your legs out like a soldier, gentle squats, torso twists or ankle circles. The article gives some more complex examples with diagrams.

Save static stretching for after your workout. This is when your muscles are relaxed, warm, and most receptive to elongation that can lead to better range of motion.

I have learned in my recent studies just how important warm-up and cool-down are for the body. It takes a little extra time but is so worth it to avoid injury, promote faster recovery, and enhance your performance.


Stretch Reflex Saves the Day!

Did you ever wonder why your knee jerks when it is struck by the doctor’s hammer? Or why your head snaps up when you fall asleep sitting up? How about why your leg shakes when you try that hamstring stretch?

It’s all due to special “organs” in your muscle fibers and tendons that are protecting you from injury.

Say you are watching tv at 1am and that infomercial on Swiffer just isn’t doing it for you anymore. Your head starts to roll to the side and next thing you know you jerk yourself awake and realize your neck is stiff. This is called the Myotatic Stretch Reflex. A specialized nerve in your muscles detects that the force of your head falling is too great and would cause damage to the body so it sends a message to your brain telling it to contract the muscle that is being stretched too far. Snap! You are suddenly awake and realizing maybe QVC doesn’t need your business after all.

When the doctor hits your knee with the hammer it is a similar reflex, only this one involves the Golgi Tendon Organ. This does the same thing as the Myotatic Reflex but for your tendons. The blow to your patellar tendon causes a forceful stretch that the Golgi reflex shuts down by contracting your quadriceps.

And the hamstring shake? This one happens to me all the time. When you are laying on your back and pulling your leg higher into the air your Golgi and Myotatic reflexes engage which stops your stretch, so you pull harder, the reflexes continue to engage, etc. You are playing tug-o-war with yourself! It may not feel as effective, but it’s time to back off the stretch and hold it for a longer amount of time at the point where shaking ceases.

This concludes your spin-off of G&D Discuss Science. Class dismissed!

Fitness Facts

Most of you know that I have decided to get my personal training certification and will also be getting a Nutrition Specialist certificate through SWIHA. I am into day 3 of my studies now and I am already learning so much! I thought as I discover some interesting tidbits that I would share the knowledge with you, my faithful readers, since most of you are fitness fiends yourselves.

Did you know that as your aerobic fitness level increases you body actually builds new capillaries to supply your muscles with more oxygen? How cool! I didn’t know it could do that!