1.
 A currently popular trend among
endurance athletes is eating a high-fat
diet to increase the muscles’ reliance
on fat for fuel during exercise and thus
increase endurance by sparing the
muscles’ limited glycogen stores.
Studies have shown that a high-fat diet
does increase the muscles’ reliance
on fat for fuel during prolonged
exercise, however it has no effect on
performance.

2.
 Especially drenched after your regular
afternoon run? That doesn't mean you
necessarily torched any more calories
than usual (sorry!). "Sweat is a
biological response that cools your
skin and regulates internal body
temperature," Matthews says. It's just
as apt to be the result of an
overheated studio, the weather or
your personal physiology as it is a
grueling gym session.

3.
While stretching may not
completely reduce muscle
soreness or speed muscle
tissue repair, limbering up still
has certain benefits, Westcott
says: Doing it right after a
workout, when the body is still
warm, is the best way to
increase joint flexibility.

4.
 Carbo loading, or the practice of increasing
dietary carbohydrate intake in the days
preceding a race, is a familiar ritual for most
runners. But it’s seldom necessary. Research
has shown that carbohydrate loading has no
effect on performance in races lasting less
than about 90 minutes. Also, its effect is
minimal even in longer races when
adequate carbohydrate is consumed during
the race. Endurance athletes as successful as
six-time Ironman winner Dave Scott have
never carbo-loaded. That said, it does no
harm, so if it gives you confidence, go ahead
and load up.

5.
It doesn’t always mean that
if you are having work outs
and you don’t feel pain,
nothing is changing. As
long as you do the proper
work out, you will achieve
the fitness and body shape
you wanted to have.

6.
 They may be the most iconic
abdominal exercise around, but doing
crunches is not actually the best way
to slim your midsection. If you are
doing crunches, make sure to use
proper form: Otherwise, they may put
your spine in a painful curved
position. "Since they don't burn off a
lot of calories, they don't help in a
major way with fat loss."

7.
Full squats are
actually good for your knees.
Do this, stay on your heels as
much as you can while you're
at it, and your knees will stay
healthy long into old age.

8.
 The only way to lose the right
amount of weight is by adopting a
diet than supports your goal,
training with weights, and doing
some cardio. Your program
should include all of these
aspects long enough to see a
difference. Diet, weights, and
cardio—the holy trinity of fitness!

9.
 Eat lots of vegetables, fruits, and
fiber-rich grains. If you’re training
for a long endurance event or
century ride, eat a lot of carbs,
“probably at least 50 percent of
your diet.” Fill the rest of the tank
with heart-healthy fats from nuts
and olive oil, and lean protein
sources, such as white meats.

10.
 Sugar, in the form of glucose is the most
important energy source for intense endurance
exercise. Dozens and dozens of studies have
demonstrated that supplementing your body’s
supply of glucose fructose, and other simple
sugars that are easily converted to glucose
during exercise enhances performance in
workouts and races lasting longer than an hour.
Despite this mountain of evidence, many runners
still avoid using sports drinks and energy gels
containing simple sugars because they are
accustomed to thinking of sugar as “bad.” But
sugar is only bad when you’re not running. When
you are running, sugar is good!

11.
 The idea that exercise-related muscle cramps are
caused by dehydration and/or electrolyte depletion
originated from a single flawed study conducted
almost a century ago.
Instead, muscle cramping appears to be a symptom
of a type of neuromuscular fatigue that is caused by
unaccustomed exertion (this is why muscle
cramping occurs almost exclusively in races) and
occurs in athletes who have some sort of innate
susceptibility to cramping. Drinking more fluid and
consuming more electrolytes have not been shown
to reduce cramping risk in susceptible athletes in
races, with the exception of one study showing that
sodium-loading before prolonged exercise delayed
the onset of cramping

12.
 Your fitness success depends upon
your goal. If you want to be able
to run 10 miles without breaking a
sweat, then yes, you'll have to run.
 If your goal is fat loss or muscle
gain, running for miles and miles
may not be the best way to lose
pounds. The more efficient your
body becomes at running, the
fewer calories you'll burn.