"The Secret to Weight Loss Through Exercise" Most overweight individuals evidently tend
to choose exercise as their first approach
to weight loss. When unrealistic hopes
clash with reality, the disappointment
may lead to an abandonment of weight-loss efforts
altogether as an exercise in futility,
no pun intended. Our false expectations may also
give us license to overeat. Our pie-in-the-sky notions
about the power of exercise may just be used to justify
an extra slice of pie right here on earth. Some researchers warn
that labeling menus with calorie equivalents
of exercise could be counterproductive, backfiring if people
rationalize their indulgences after a workout. This concern has actually been
put to the test. Exercise psychologists
took a group men and women, put them on a stationary bike, and had them cycle
until they burned either 50 calories
or more than 250 calories. Unbeknownst to them,
the researchers manipulated the machines
to give false readouts, such that in actuality both groups burned
the same number of calories.
They just thought
they burned more or less. Then, they were offered a meal
10 minutes later, ostensibly to measure the "effects of exercise
on taste perception," but the real purpose
was to covertly measure how much people ate. Those who falsely believed they had burned off
more calories did seem to demonstrate
a greater "license to eat," ending up eating
significantly more calories, mostly in the form
of chocolate chip cookies. After a workout,
people may be tempted to treat themselves
for their sweaty sacrifice. To prevent
this kneejerk reaction from undermining our efforts, we should strive to make
exercise less of a chore. In a paper entitled
"Is it fun or exercise? The framing of physical activity
biases subsequent snacking," a study is described in which
individuals were randomized to the same amount
of physical activity but just described differently. Half were told they were going
on a "scenic walk," and the other half were told they were going on
an "exercise walk." Afterwards,
researchers covertly measured how much dessert everyone took
at a subsequent meal.
Those in the
movement-as-exercise group reportedly served themselves about 35 percent more
chocolate pudding than the movement-as-fun group. This is all the more reason
to choose activities that are enjoyable, such as walking with friends
or while listening to music, or watching a video
on the treadmill. Reframing exercise as play
rather than work may not only make
for a more sustainable regimen but may make us less likely to consciously
or unconsciously feel the need to later reward ourselves
at the buffet line. Even just thinking
about exercise may compel people
to eat more food. Those randomized to simply read
about physical activity went on to serve themselves
nearly 60 percent more M&Ms than those
in the control group, adding up to hundreds
of extra calories. The researchers concluded:
"simply imagining exercise leads participants to serve
themselves more food." Expending energy
through exercise may not just psychologically
predispose us to eat more but may physiologically
make us hungrier. We evolved in the context
of scarcity, so our body
places great value on rapidly replenishing
lost fat stores. This helps explain why
the average weight loss with exercise training is only 30 percent
of that predicted based on the number
of extra calories burned.
Calories in
versus calories out can be complicated
by the fact that changes on one side
of the equation can affect the other side. In other words,
we can work up an appetite. Carefully controlled studies show that caloric intake
tends to rise over time to match any increase
in caloric expenditure, making significant weight loss
through exercise alone remarkably difficult. This doesn't happen
over a day or two. After a workout, there may not be
an immediate increase in hunger, but averaged over the week
or weeks, our appetite does tend
to increase to balance out most of the extra calories
we've been burning.
This calorie compensation
isn't perfect, though, so we can end up
with a net loss in body fat, particularly at
higher exercise levels. So, the secret to weight loss
through exercise may be sheer volume, at least 300 minutes a week to achieve
appreciable fat loss. This regulation of our appetite
through activity works in both directions. Just as there exists
a higher level of exercise where we can start to outpace
our appetite and lose weight, there's a lower level
of exercise where our body
loses the ability to sufficiently downgrade
our appetite, and we gain weight.
This sedentary zone
where our appetite becomes uncoupled
from our activity level appears to start
at around 7,100 steps a day. So, let's say you start out
as a really active person, chowing down on
nearly 2,900 calories a day, and, for whatever reason,
have to cut back on exercise. You'd think you'd gain
a lot of weight, but you're surprised
that you don't. Basically, no increased odds
of gaining significant body fat. What happened? With your drop in exercise came
an inadvertent drop in appetite. But there's a limit to how far
our appetite can drop.
Once you cross that threshold, once you dip below logging
at least 7,100 steps or so a day on your pedometer, your appetite doesn't slow
much further to match, and the pounds can start
to pile on. Your body tries
to keep your weight steady by adjusting your appetite, but we just weren't designed to handle such extreme
low levels of movement that sadly characterizes
most of the U.S. population..