Power to (All) the People

I once sat in a class on power development being taught by a “master trainer,” who posed a seemingly innocent question: “Who needs power?” The obvious answers surfaced, such as athletes and physical laborers. 

When I chimed in with “seniors,” the instructor stared at me with a combination of disbelief and snide condescension. He then asked me,

“So, you would do a kettlebell swing with grandma?” 

“Absolutely,” I responded, “because seniors lose a disproportionate amount of fast-twitch fibers and the ability to quickly react to a missed step to avoid falling.” 

He refused to agree with me, which is fine, but I wanted to make the point to the dozens of uninitiated trainers in the room eagerly soaking in this guy’s “wisdom.”

I also want you to understand that, regardless of your chronological age or training experience, you need power training in your program.

First, it's important to understand how your body changes throughout adulthood, beginning at the tender age of 30 (1, 2):

  • Muscle mass and strength decrease by 25%-30%. In addition, fast-twitch type II fibers are lost in a disproportionate amount. Consequently, power decreases.
  • Nervous system function declines; there is a decrease in the number of total brain cells, motor unit size, and conduction velocity while synaptic delay and reaction time increase.
  • Bone density decreases between 10%-30% (women lose the most).
  • Cardiovascular capacity decreases, including the following: VO2 max, stroke volume, anaerobic power.

Your habits and lifestyle choices will certainly impact the severity of the decrements listed above. And the good news is that training can help offset these changes

 Now 79, Ernestine Shepherd holds the title of Guiness World Records' oldest female bodybuilder.

Now 79, Ernestine Shepherd holds the title of Guiness World Records' oldest female bodybuilder.

However, decreases in sensory system functioning are not really trainable and they do have a significant impact on movement production. A few examples (3):

  • Sensory receptors decrease, especially on the bottom of the feet, making seniors less able to take in critical information when walking or even in quiet stance. (Big, orthopedic shoes designed for comfort and stability will mask even more sensory information.)
  • Loss of 40% of vestibular hair and nerve cells in the ears, which help to sense changes in inner ear fluid (reducing kinesthetic awareness and accurate orientation in the environment).
  • Vision changes, especially in depth perception, prevent accurate assessment of the environment, increasing the likelihood of missteps and falls.

Considering the vast physiological and sensory changes listed above, it becomes easier to understand how you might trip, fall, or experience performance declines if you are in your second act of life (50+).

Conventional thinking is that, if you are a senior exerciser, you should take a conservative, even gentle approach to physical activities (read: a slow tempo) so as to reduce injury potential. While I agree that slow, deliberate practice of movement mechanics is critical for building a solid physiological foundation, you also need to develop the ability to produce force rapidly for real-world situations.

To me, the most salient example of why power training is so important relates to walking pace. Research has been done on the timing of traffic lights to allow pedestrians to safely walk from one curb to the other in an intersection. New Haven, CT, East Boston, MA, and Los Angeles, CA are among some of the cities that have lights timed to allow a person to cover an intersection while walking at a pace of 1.22m/s (4 ft/s) (4). However, over 96% of subjects involved in multiple studies walked slower than 1.22m/s, putting them at risk every time they crossed the street (5).

 A daily task that can become life-threatening.

A daily task that can become life-threatening.

In my hometown of New York City, I cringe when I see impatient cars bearing down on slow walkers, hoping for a safe outcome for the pedestrian. I use that image to fuel my work with my over-60 clients. They don’t need to move quickly all the time but that ability needs to be at their disposal when necessary.

How You Can Power Up Your Training

As long as you are progressed properly there is no reason why you can’t become more powerful. Even if you have physical limitations you can simply speed up the tempo of whatever exercises you are currently able to do, resulting in increased force production and the ability to summate forces more quickly.

Here are more power training tips to implement into your workouts:

  • Increase weights
    • The more weight you move the more force you produce. And force is a prerequisite for increasing power output. So, hit the heavier weights at least once a week to stimulate the precious fast-twitch fibers that are so critical to moving faster.
  • Increase tempo
    • Every movement has two phases (concentric=muscle lengths getting shorter, eccentric=muscle lengths getting longer). Performing movements at a slow tempo won't stimulate power as much as speeding up one, and then both, phases of a movement. Make sure that you can execute both phases quickly and accurately.
  • Incorporate sensory cues prior to producing a rapid movement
    • Just as crossing a street requires a visual stimulus (green light) to initiate the appropriate response (begin walking), try to incorporate visual or auditory cues before squatting, lunging, pulling, or pressing. This is easier if you have a gym buddy or willing partner. Have that person make a hand gesture or sound and then try to respond with your squat as quickly as possible. The less of a delay between cue and movement the better.

As long as you keep in mind the demands of real-world situations, from crossing the street to heaving a heavy suitcase onto a luggage rack, you can better prepare yourself to be successful at those tasks. 

Power up your program today.

Keep on Movin’

-CA

 

References:

  1. Gabbard, C.P. (2008). Lifelong Motor Development (5th ed.). San Francisco, CA: Pearson Benjamin Cummings.
  2. Brooks, G.A., Fahey, T.D., & Baldwin, K.M. (2005). Exercise Physiology: Human Bioenergetics and Its Applications (4th ed.). New York, NY: McGraw Hill.
  3. Shumway-Cook, A., & Woollacott, M.H. (2007). Motor Control: Translating Research into Clinical Practice (3rd ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
  4. Hoxie, R.E, & Rubenstein L.Z. (1994). Are Older Pedestrians Allowed Enough Time to Cross Intersections Safely? Journal of the American Geriatric Society. 42, 241-244.
  5. Langlois, J.A., Keyl, P.M., Guralniik, J.M., Foley, D.J., Marottoli, R.A., & Wallace, R.B. (1997). Characteristics of Older Pedestrians Who Have Difficulty Crossing the Street. American Journal of Public Health, 87(3), 393-397.