February Fitness and the Truth About Stretching

During the last 2 weeks before Mid-Winter break, students reconnected to their cardio-respiratory fitness.  The 2-4th grades learned fitness circuits; spending just 2 minutes at one station doing one exercise before quickly moving onto the 4 more stations to do 4 more exercises, yielding up to 10 minutes of non-stop exercise for the full body.  By keeping the movement going from one thing into the next, students keep their heart and respiration rates elevated.  By switching exercises every 2 minutes, no one muscle group gets over-burdened.  These dynamic efforts also encourage students to engage their personal determination and to find mental strategies for toughness and perseverance.  Many students enjoyed using medicine balls and weighted bars to increase the burden of their labors.  The 1st graders students spent this time rehearsing their Penguin Dances and all classes enjoyed at least one obstacle course.  Kindergarten enjoyed several obstacle courses and lots of matwork.

PE also introduced stretching.  Stretching is one of the most mis-understood parts of active lifestyles that it is worthy to examine it in some detail here.  Stretching is simply pulling unwanted tension from muscle fibers.  This is usually accomplished by tensing antagonistic muscle groups (to stretch the muscles on the front of my thigh, I engage the muscles on the back of my thigh), by using hands or straps to pull, or by using partners or even gravity.  So when should we give our muscles this pull, for how long, and why?

•  Before Exercise
• This is completely dependent upon what type of exercise.  It is beneficial to warm-up or loosen-up before exercise, and this should include moving through the range of motion that the exercise will demand.  For running, this would include some ankle and toe articulations, hip and knee flexion, rotation in the lower spine and pelvis, and even swinging of the arms, but actually stretching the muscles causes tiny tears in the fibers.  Those tears will impair the performance of the muscles during the run.  If, however, the exercise is ballet or gymnastics, figure skating or Tae Kwon Do, then the range of motion used is far greater and warming or loosening that range of motion may indeed require stretching those muscles.  In general, however, it is safer to think of the activity before exercise as loosening the range of motion rather than stretching.
• During Exercise
• During the course of repetitive tension and relaxation of muscles, it is possible for muscles to fail to relax.  Sometimes this tension is a shrugged shoulder or tight muscle that wastes a little energy but does little harm.  Sometimes, though, a muscle very important to the task or exercise seizes, very tense, and cramps.  Often, the antagonistic muscle groups (generally, those on the other side that execute the inverse or opposite movement) can not alone overcome the tension in the cramped muscles, and a manual pull is needed to relax the muscle fibers.
• After Exercise
• Remember those tiny tears in the muscle fibers discussed above?  Similar damage happens to our muscles during exercise.  Exercise is indeed somewhat traumatic.  It is because our bodies want to reduce the trauma that they then rebuild themselves a little bit stronger after exercise- so that future efforts will create less trauma. Since the damage is done during exercise, adding a stretch to the end of your workout does not really create any new damage, and will not impair the workout.  Indeed, the benefits of stretching after exercise seem to include
1.  improved gas transfer, moving CO2 (and toxins) out of the muscles and out of the body
2. better re-hydration
3. maintained or improved range of motion
4. release of unnecessary tension
5. decreased recovery time, and more
• There is evidence that holding a stretch for any less than 30 seconds does not give muscles sufficient time to benefit.  Stretching is also fairly ineffective if breath is held (remember, one job of stretching is to boost gas transfer and toxin removal), so we hold every stretch for at least 5 deep breaths.

Next in PE: Hockey!

Stay Healthy; Breathe Deeply,

Matthew Smith