17 July 2021 | New Scientist | 35effect on overall flexibility. A 2012 analysis by
the US Institute of Medicine in Washington DC
of data from the now-defunct Presidential
Physical Fitness Test, which, between 1966
and 2012, included a sit-and-reach flexibility
test for all US schoolchildren, found that
flexibility in young people had decreased
over the decades, particularly among boys.
By early middle age, the most sedentary
people are so stiff that they can injure
themselves even while sitting at a desk.
“We see that starting at age 30 or so, people
get problems from non-sporting activities
like moving the computer mouse,” says
Markus Tilp at the University of Graz
in Austria, who studies stretching.
What’s more, it isn’t just the physical
act of sitting that leaves us feeling tight.
Concentrating on a mental task contributes
to tension in the shoulder girdle, arm and neck.This is partly because when we focus our eyes
on a screen, we often tense our shoulders to
increase our ability to focus visually (and
mentally). One study found that the trapezius
muscles in the upper back, which help keep
the head upright, are particularly sensitive
to the difficulty of the task – the more we
need to concentrate, the more they tense up.
For people who sit a lot and are under a
lot of stress, then, stretching and mobilising
stiff parts does relieve tension and lengthen
muscles – at least temporarily (see “What
happens when you stretch?”, page 37). It is
also well known that, when done regularly,
stretching can lengthen muscles and
connective tissue, restoring their length and
a full range of motion to underused joints.
Which sounds like case closed for the
benefits of stretching, especially for those who
feel their bodies are tight, weak and inflexible.
But this doesn’t necessarily mean we should
devote lots of time to stretching to get more
flexible as part of an exercise regime. In fact,
according to exercise scientist James Nuzzo,
this type of stretching isn’t worth the effort.
Nuzzo says that the hype about stretching
dates to 1980 when exercise scientists >“ Sedentary
lifestyles
are having a
knock-on effect
on flexibility”