"Enhanced Athletic Recovery Without Undermining Adaptation"
Ultramarathon runners may generate
so many free radicals during a race
that they can damage the DNA
of a significant percentage of their cells.
Now some have looked on the exercise-induced increase
in free radical production as a paradox.
Why would an apparently healthy act, exercise,
lead to detrimental effects through damage
to various molecules and tissues?
This is somewhat of a misunderstanding
as exercise in and of itself is not necessarily the healthy act,
it's the recovery after exercise that's so healthy.
The whole that-which-doesn't-kill-us- makes-us-stronger notion.
For example, "Exercise training has been shown to enhance"
"antioxidant defenses, for example"
by increasing the activities of antioxidant enzymes.
So yeah, during the race ultra-marathoners
may be taking hits to their DNA,
but check out a week later.
Six days after the race,
they didn't just go back to the baseline level of DNA damage,
they had significantly less,
presumably because they had so revved up their antioxidant defenses.
So maybe, exercise-induced oxidative damage is beneficial,
kinda like vaccination.
By freaking out the body a little,
maybe you'll induce a response
that's favorable in the long run.
This concept that low levels of a damaging entity
can up-regulate protective mechanisms
is known as hormesis.
For example, herbicides kill plants.
But in tiny doses may actually boost plant growth,
presumably by stressing the plant
into rallying its resources to successfully fight back.
Wait a second, though.
Could then eating anti-inflammatory, anti-oxidant rich plant foods
undermine this adaptation response?
We saw that berries could reduce inflammatory muscle damage,
and greens could reduce the free radical DNA damage.
Dark chocolate and tomato juice may have similar effects.
The flavonoid phytonutrients in fruits, vegetables, and beans
appear to inhibit the activity of xanthine oxidase,
considered the main contributor of free radicals during exercise.
And the carbs in plant foods
may decrease stress hormone levels.
So in 1999, a theoretical concern was raised.
Maybe all that free radical stress from exercise is a good thing,
and increased consumption of some antioxidant nutrients
might interfere with these necessary adaptive processes.
So if you decrease the free radical tissue damage,
maybe you don't get that increase
in activity of those antioxidant enzymes.
The cherry researchers responded,
look, although it's likely that
muscle damage, inflammation, and oxidative stress
are important factors in the adaptation process,
minimizing these factors may improve recovery
so you can train more and perform better.
So, there's kinda theories on both sides,
but what happens when you actually put it to the test?
What does the data show?
While antioxidant or anti-inflammatory supplements
may prevent these adaptive events,
researchers found that a berry extract—
black currant in this study,
although packed with antioxidant
and anti-inflammatory properties
actually augmented, boosted the health effects
of regular exercise even further.
But you take antioxidant pills
—vitamin C and vitamin E supplements —
and you can actually reduce the stress levels
induced by exercise,
but in doing so you can block that boost
in antioxidant enzyme activity caused by exercise.
Now maybe you don't need that boost
if you don't have as much damage,
but vitamin C supplements may impair
physical performance in the first place.
Whereas with plant foods,
you appear to get the best of both worlds.
Check out this recent study on lemon verbena,
an antioxidant-rich herbal tea.
Protects against oxidative damage,
decreases the signs of muscular damage and inflammation,
all without blocking the cellular adaptation to exercise.
They showed that lemon verbena
does not affect the increase of the antioxidant enzyme
response promoted by exercise.
On the contrary, glutathione reductase activity
was even higher in the lemon verbena group.
Here's the level of antioxidant enzyme activity
before and after 21 days
of intense running exercises in the control group.
With all that free radical damage that, that caused,
the body started cranking up it's antioxidant defenses.
But give a dark green leafy tea,
and not only do you put a kabosh on the damage
due to all the phytonutrients antioxidants,
you still get the boost in defenses—
in fact, in this case, even better.