More than 750
scientific studies
demonstrate
the positive
relationship
between sleep
and athletic
performance.
Here are just some of the many
things known. Sleep for fewer
than eight hours nightly, especially
fewer than six, and your time to
physical exhaustion drops by
up to 30% with a similar reduction
in aerobic output. Your metabolic,
respiratory, and cardiovascular
capabilities are hampered. Lactic
acid builds up faster. The ability
to cool yourself via sweating
is impaired. Motor skills are
reduced. One study showed the
odds of athletic injury were nearly
doubled by a two-hour sleep
deficit. All of the above can wreck
a workout, and that’s before we
even address strength. What’s
more, research points to the
final two hours of an eight-hour
sleep—a phase when the brain is
putting it all together, completing
the physical and mental tune-up,
so to speak—as critical to athletic
performance.
NAPS ARE
AMAZING
STRENGTH
Some studies demonstrating
the benefits of sleep focused
on peak and sustained strength.
One of these limited eight male
subjects (ages 18 to 24) to three
hours of sleep per night for three
nights. Those subjects suffered
significant and progressive losses
of strength in the bench press,
leg press, and deadlift.
of hormonal deficits.) We don’t
need to tell you how crucial
testosterone and growth hormone
are to bodybuilding success, and
both are replenished with eight
hours of sleep.
FAT METABOLISM
TESTOSTERONE
If you think slumber makes you
soft and an alpha dog would
never go eight, consider that a
study of men in their 20s—limited
to five hours of sleep per night for
a week—discovered that their
testosterone levels had dropped
so dramatically that they had
effectively “aged” by 10 to 15
years. (Furthermore, both men
and women who sleep too little
are markedly less fertile because
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FLEX | MARCH ’18
Similarly, many associate sleep
with growing fat. After all, you burn
more calories when awake than
when not. To the contrary, you
should associate sleep with getting
lean. Multiple studies prove that
you crave more sugary foods
(high-glycemic carbohydrates)
when sleep deprived and that
your body is less efficient at
metabolizing calories. For an even
scarier conclusion, consider the
study that monitored two groups
of individuals on calorie-restricted
diets. Group A slept five and a
half hours nightly. Group B slept
eight hours. Some 70% of group
A’s calorie loss came from muscle
compared with 50% from group B.
Conclusion: Sleep is crucial to
not just appetite control and fat
metabolism but also muscle
preservation.
EMOTIONAL HEALTH
A wealth of research
demonstrates that a sleep deficit
hurts your emotional equilibrium—
you grow frustrated and angry
faster—and your ability to focus
on tasks. These factors can
negatively impact workouts
where attention and motivation
are paramount.
“I know I should
get eight hours, but
I’ll admit that I
sometimes get only
six. My schedule is
just so damn busy
at times. But what
I try to do then is
get a one-hour nap.
I love naps! Naps
are amazing.”
—P HIL H EATH