Senior Exercise (cont.)
Can I get stronger without building big muscles?
Importantly, strength isn't just a function of mass. It's also a function of something called "neurological
patterning." In layman's terms, patterning is when the brain sends electrical
signals via the nervous system to muscles to make them contract. For example,
when you think about walking down the street, bending over to pick something
up, or any other movement for that matter, the brain first processes the thought
and figures out what muscles are needed to make the move and then sends the
signal over the nerves to the particular muscles that are necessary for the
movement. The muscles move (and so do you) once the signal reaches them. (See
"How muscles work" for more detail.)
The good news here is that muscle patterning improves within days of starting a
weight-lifting program, even without any increase in muscle mass. This explains
the 113% increase in strength experienced by the residents of the nursing home
in Boston I just mentioned. In a different study that specifically investigated
this phenomenon, 67- to 81-year-old men lifted weights for six weeks while
hooked up to electrodes that measure nerve and muscle patterning (an
electromyogram machine). The results showed that the men experienced a 25%
increase in the patterning of the muscle along with a 35% increase in strength,
all without significant increases in size.
What happens to endurance as we age?
Endurance decreases as we age. In one study of more than 3,000 70-79-year-old men and women, researchers
investigated the relationship between the speed at which these subjects walked
¼ of a mile and their risk of premature mortality, cardiovascular disease, and
mobility limitation. The results showed that those with the slowest walk times
(>6 minutes) had a higher risk of death, cardiovascular disease, and mobility
limitation than those who walked the distance in less than four and a half minutes. In fact,
every additional minute of walking time was associated with higher and higher
degrees of risk; approximately 13% of the participants could not even complete the
distance due to fatigue or symptoms (breathlessness, cramping, etc.).
There's good news when it comes to fitness, walking endurance, and health. In a classic
study of walking and mortality in 700 men enrolled in the Honolulu Heart Program, the mortality rate among the men who walked less than one mile per day was
nearly twice that among those who walked more than two miles per day (studies of
women show equally potent results). In another equally impressive study, data
collected on more than 41,000 men and women from 1990 to 2001 were analyzed to
find the relationship between walking and mortality. It was reported that men
and women who walked 30 minutes or more per day during the study period had
fewer deaths than those who walked less than 30 minutes. Interestingly, even men
and women who smoked or were overweight were protected from early death if they
walked more than 30 minutes per day.
Next: What happens to flexibility as we age? »