Stretch Shortening Cycle



The fundamental elements of human power production are: high-speed strength, low-speed strength, speed of force production, strength-shortening cycle and muscle memory or skill. The first three elements are trained in the gym, the fourth is a gift of nature and the fifth means that you could be the most perfect physical specimen ever to walk the earth and you wouldn’t be able to chew gum and walk, unless you practiced chewing gum and walking, of course. Let’s talk for a moment about number 4.

Do you remember the classic scene in the doctor’s office where the patient is sitting on the exam table and the dr. hits his knee with a rubber hammer and the patient’s leg kicks out? That is a demonstration of the stretch shortening cycle. A perfect example of the body’s defense mechanism against overstretching, when the hammer hits the tendon over the knee and quickly shortens the quadricep muscle, the brain immediately tells the quad to contract and simultaneously keeps the opposing muscle, the hamstring, relaxed so that there is no opposition to the leg’s movement, preventing overstretching. The same phenomenon can be seen in weight training, called ‘bouncing out of the squat’, the athlete lowers the weight under control until, at the very bottom of the squat the pre-stretched muscles rebound to start the weight up again.

The stretch shortening cycle is a built in part of the human machine but knowing what it is and what it does can help us in getting to know our bodies better. Plyometrics is a subject that really embraces the stretch shortening cycle, many of the movements rely on it for their effectiveness. One of my favorite exercises is platform jumping or box jumping. Many people do this in their workouts, but there are two ways to do this and two very different results.

The basic box jump starts with the athlete standing in front of a wooden platform and jumping from the floor to the top of the box, fully extending the hips each time and jumping back down to the floor. If you can do this, awesome. Now think about this, start on top of the box, jump to the floor and spring back onto the box without pausing at the bottom. This is where the stretch shortening cycle lives. Try this ten times with a small box or snatch block, 6 to 8 inches tall to begin with. Rest at the top instead of the bottom if you need to and try to keep your heels from touching the ground when you land at the bottom, this leaves all of the stretch in your legs. The first several times be careful as there is a component of skill and balance involved in getting back to the same spot you started each time. Think unicycle, don’t hurt yourself trying to help yourself.

workout: run 1 mile, no stops

Crunching the Numbers




Rule 34 states that ‘If it exists, there is porn of it.’  I believe that in the realm of health and fitness, if one person has had an idea, two other people have figured out how to count it, collate it, and quantify it.  One such idea is the Banister Impulse/Response model.  The idea was at first to figure out if, by recording all training efforts, an increase in fitness could be calculated by means of an ordinary differential equation and the answer given in the form of positive training effect, or PTE.  It almost worked.  For every positive training effect there is a negative effect, that being fatigue.  Rather than shoot down the original hypothesis however, this little fact seemed to have perfected it.  When the PTE is plotted against the NTE over time along with actual performance an interesting and quite repeatable effect is shown.


Skipping all of the math, we see that at the beginning negative effects, basically fatigue, outweigh the positive effects of training.  As performance starts to improve the positive effects become substantially greater than the negative.  This model has been tested for many endeavors, running, cycling, swimming, and seems to work similarly in all of them.  More here.


I have a confession to make. I fell off the wagon, yes, stopped making fitness a priority and forgot about eating right and it got me. On top of not making weightloss goals and feeling pretty low from the lack of endorphins, I got a chronic hip pain. So I am back at square one, actually square zero, I have lost the ability to squat temporarily. I am slowly rehabbing the range of motion while I try to catch up in other areas.

It is iced tea season once again, there is 3 gallons of the stuff in the refrigerator right now, good hydration is one of the very basic things I am concentrating one as the summer progresses. Purging useless carbs, refined flour and sugar, and getting back to fresh greens and such. Baby steps, the goal is not a ‘diet’ but a lifestyle change, a permanent one.

Prying myself away from the computer screen is underway. Walking the dog a mile at a time, up to 3 times a week now to mobilize the hips and get the wind back. Weight training again starting with Bench, Deads, Lat pulldowns and Power cleans until the squat comes back.


Dog walking= 1 mile, large dog, his pace not mine.


8 oz, sausage, 6 eggs Calories 1376 Protein 81.8 g. Fat 95.8 g. Carbs 0 g.

10 oz. Grd beef+ 2 med onions 518 cal Protein 45 g. Fat 31 g. Carbs 11 g.

Chinese buffet Don’t judge me.


Making good habits

Changing things that I don’t like about myself used to be next to impossible.  Each time I would encounter a behaviour or habit that I didn’t like I would think to myself, ‘I should do this instead or that instead’ and inevitably that would be the last I thought about it, until the next time.  Over the years I discovered that the one common thread in all of these failed attempts at bad habit breaking was taking a good, solid first step.  Not just a change in direction but a change in goals that leads to a measurable result.

On May 8, 2011 I weighed around 315 pounds, had no energy, no wind, could not tie my shoes or even see my feet without incredible difficulty, I had had enough.  I was going to die, and soon, if I did nothing.  I was going to start doing something I just didn’t know what yet.  Long story short, I found a gym that I liked, showed up every day and did the best that I could and today, after almost 3 years I feel like I am making  some serious progress.  All because I took a focused, determined first step.

There is no one magic solution to combating bad  habits, the number one enemy of bad habits is the desire to change, that is where the power  is.  Some people would benefit from changing only one small thing at a time, chipping away slowly at ingrained behaviour.  Others may need a complete 180 degree shift from the norm to effect a difference.  If you look at the words used to describe habits, entrenched, established, deep-rooted, deep-seated, fixed, firm, unshakable, ineradicable, well established, it seems the words themselves are a considerable hurdle to overcome.  Courage, determination, self-will, drive, initiative, you will need all of these at one time or another to overcome bad habits.

An interesting approach to habit breaking or rather, good habit making is the 7-week or 49 plan.  Pick some good habit that you would like to have, write it down on an index card and then draw 6 vertical lines and then 6 horizontal lines making a 7×7 grid.  Each day that you consciously work toward your desired new habit, put an ‘x’ in the box, once you have filled up the card with x’es, you are well on your way to having a good habit for life.  Start small or take as big a bite as you dare, but start, that’s the most important thing.