Intensity is Key to Muscle Growth
Mar 31, 2023 09:31AM ● By Sarah WallaceThe
science behind exercise has come a long way since the aerobic and cardio craze
that started in the 1970s, and many people that walk, jog, swim or bike
continue to lose muscle mass, but don’t understand why. They might notice some
visible signs of muscle loss and strength such as slower walking, reduced
endurance and mobility, declining posture and poor balance, and check them off
to aging. It’s called sarcopenia, the age-related (and lifestyle-related) loss
of muscle mass and strength).
Sarcopenia is also associated with some
chronic conditions like Type 2 diabetes, dementia, a few cancers,
cardiovascular diseases and visceral fat. The latest research shows muscles are
so vital to our health that many doctors are including muscle strength
measurements in addition to blood pressure, breath, weight, pulse and
temperature at annual checkups. Muscles are the foundation of our metabolic
health, and we need to strengthen them. Muscle strength is also vital at every
age.
Nothing is wrong with aerobics; movement is
fundamental, and any way we do it benefits our health. However, these forms of
exercise don't supply sufficient load to strengthen muscles, so it is vital to
incorporate high-intensity resistance training because muscles, not aerobic
fitness, will enhance our health and reverse conditions associated with
sarcopenia.
Intensity is required to gain muscle
strength because motor units and muscle fibers make up our muscles. They come
in three categories: small, endurance ones, slow-twitch fibers; mid-size
intermediate-twitch fibers; and the muscles used for explosive, high-peak
movements, fast-twitch fibers. First, the small endurance fibers start working,
and when they tire, the intermediate fibers kick in to help them recover. Then,
if needed, the big, powerful ones are activated. The small endurance fibers are
the most used, and are also the most resistant to fatigue and the quickest to
recover; that’s why we can walk for hours.
We use the slow, endurance and intermediate
fibers for most day-to-day activities. Because we don't usually go all-out and
sprint 100 yards daily, we rarely use the fast-twitch fibers—they are the first
to be weakened by sarcopenia and atrophy. Building them back requires
intensity; they need to be overloaded to grow. We do that with high-intensity
training using body weight and resistance bands, which is perfectly appropriate
for people of all ages and in any condition. Using resistance bands takes
muscles through their entire range of motion, plus movements are super-slow
without explosive motion, so this is safe for everyone.
Sarah
Wallace is the owner of Amenia Yoga – A Place for Wellness, located
at 18 Old North Rd., in Amenia, NY. Wise & Strong, a strength-building
class geared toward post-menopausal women, is offered in studio and online via
Zoom on Fridays at 9:30 a.m. For more information and additional class
offerings, visit AmeniaYoga.com.