Exercise: Just Minutes in the Morning?
Even though morning
cardio has been embraced by bodybuilders as a "tried and true" fat loss
technique, there is definitely not
a unanimous agreement about its effectiveness, especially in the
scientific community. Most competitive bodybuilders are die-hard
advocates of doing cardio first thing in the morning before eating
their first meal. They believe it will cause them to mobilize more
stored body fat and increase their metabolic rate all day long. There�s
quite a bit of scientific literature supporting the a.m. fasted cardio
theory, but generally, the exercise physiologists and scientists tend
not to buy it. They subscribe to the energy balance hypothesis, which
states; as long as you burn more calories than you consume in each 24
hour period, then the time of day you burn them doesn�t matter, nor
does whether you burn them from fat or carbohydrate.
If
you have even the most rudimentary understanding of human physiology
and physics, you have to concede that the timing of your cardio is not
the most important factor in fat loss. When you do your cardio won�t
make or break you. Simply doing it whenever it�s convenient and
following a mildly calorie restricted diet is what�s important.
However, there�s a very strong case for doing fasted a.m. cardio and if
you want to gain every legal and ethical advantage possible in your
quest to get leaner then it�s definitely something you should take a
closer look at.
The argument in favor of
fasted early morning cardio goes something like this:
1.
When you wake up in the morning after an overnight 8-12 hour fast, your
body�s stores of glycogen are somewhat depleted. Doing cardio in this
state causes your body to mobilize more fat because of the
unavailability of glycogen.
2.
Eating causes a release of insulin. Insulin interferes with the
mobilization of body fat. Less insulin is present in the morning;
therefore, more body fat is burned when cardio is done in the morning.
3.
There is less carbohydrate (glucose) "floating around" in the
bloodstream when you wake up after an overnight fast. With less glucose
available, you will burn more fat.
4.
If you eat immediately before a workout, you have to burn off what you
just ate first before tapping into stored body fat (and insulin is
elevated after a meal.)
5.
When you do cardio in the morning, your metabolism stays elevated for a
period of time after the workout is over. If you do cardio in the
evening, you burn calories during the session so you definitely benefit
from it, but you fail to take advantage of the "afterburn" effect
because your metabolic rate drops dramatically as soon as you go to
sleep.
Research supports this
theory. A study performed at Kansas State University and published in
Medicine and Science in Sports and Exercise
showed that a kilogram of fat is burned sooner when exercise is done in
the fasted state in the morning than when it�s done later in the day.
The researchers measured respiratory gas exchange, caloric expenditure
and carbohydrate and fatty acid metabolism, and found that the amount
of fat burned during aerobic exercise amounted to 67% of the total
energy expenditure in the morning after a 12 hour fast. This is
substantially higher than the 50% expenditure achieved when the same
exercise was done later in the day or after eating. A similar study
from The Journal of Applied Physiology looked at the
effects of aerobic exercise on lipid oxidation in fed versus fasted
states. The researchers concluded, "our results support the hypothesis
that endurance training enhances lipid oxidation in men after a 12 hour
overnight fast." Yet another scientific paper, Optimizing Exercise
for Fat Loss,"
reports, "The ability of exercise to selectively promote fat oxidation
should be optimized if exercise is done during morning fasted
metabolism."
Despite
the fact that increased fat burning from morning aerobics seems logical
and is backed by research, the majority of scientists and exercise
physiologists vehemently deny its effectiveness. They are quick to
point out that you can find a study to support almost any theory you
want to advocate. Interestingly though, even the most dyed in the wool
academics agree that you�ll burn more fat in the fuel mix as compared
to sugars. The real controversy lies in whether this fact has any
impact on overall fat loss in the long run.
Exercise Physiologist
Greg Landry, MS, author of "The Metabolism System for Weight Loss
and Fitness,"
explains, "I agree that you burn a fuel mix that is a little higher in
fat if you�re exercising on an empty stomach. However, I think the real
question is, does that matter? I believe we have a �pool� of calories
stored in different forms in the body (fat, glycogen, etc.), so
�burned� calories all come from the same pool. Thus, it really doesn�t
matter that the fuel mix has a little more fat in it at a given time.
If it�s pulling from fat stores at that time, then it�s pulling less
from glycogen stores and thus future consumed calories will be a little
more likely to be stored as fat because glycogen stores are a little
fuller. So it�s all a wash."
Lyle McDonald, an expert
on bodybuilding nutrition and author of "The Ketogenic Diet," agrees.
He argues that the body will compensate later in the day and is simply
"too smart" for strategies like this to ever work: "All that research
says is that you burn a greater proportion of fat this way,
which I agree with 100%," says Lyle. "The majority of research shows
that as far as real world fat loss goes, it doesn�t really matter what
you burn. Rather, 24-hour calorie balance is what matters. Because if
you burn glucose during exercise, you tend to burn more fat the rest of
the day. If you burn fat during exercise, you burn more glucose during
the day. The end result is identical. If that weren�t the case, then
athletes like sprinters who never �burn fat� during exercise wouldn�t
be shredded. Basically, they burn so many calories that they remain in
balance and don�t gain any fat. So, while morning cardio probably
provides some psychological benefits to bodybuilders who are programmed
to do it that way, I can�t say that I think it will result in greater
�real world� fat loss, which is what matters."
When
it comes to "real world" fat loss, few people have more experience than
Chris Aceto. A successful bodybuilder and nutritionist to some of the
top pro bodybuilders in the world, Aceto is a firm believer in morning
cardio. He unequivocally states, "The fastest way to tap stored body
fat is to do cardio first thing in the morning on an empty stomach."
Aceto
believes that looking at calories only in terms of energy in vs. energy
out is "limited thinking." He asserts that there are more factors
involved in "real world" results than just energy balance. This all
comes back to the old argument, are all calories created equal?
"Absolutely not!" Aceto declares. "A calorie is not just a
calorie and exercise physiologists �freak out� when they hear this."
"These
guys are working from the assumption that it�s just a matter of
calories in vs. calories out, period," Chris continued. "With that line
of reasoning, they�d be forced to say that if I consume nothing but
candy bars and Coca-Cola, and take in 100 calories less than
maintenance, I�d lose weight. We know it�s not that simple. You also
have to account for ratios of carbs, protein, and fat. Then there�s
meal frequency too: From real world results we know you put down more
muscle mass from 5 or 6 meals a day than from 3 meals a day. There are
more things involved than just calories."
Whether
or not morning cardio in the fasted state increases "real world" fat
loss is still the subject of controversy, but there are many other
reasons you might want to consider making it a part of your daily
routine. Landry, despite his doubts about whether the fuel source
matters, admits, "If I had to pick a single factor I thought was most
important in a successful weight loss program, it would have to be to
exercise first thing in the morning."
Here are some of the
additional benefits of doing cardio early in the morning:
1.It makes you feel
great all day by releasing mood-enhancing endorphins.
2. It "energizes" you
and "wakes you up."
3. It may help regulate
your appetite for the rest of the day.
4. Your body�s circadian
rhythm adjusts to your morning routine, making it easier to wake up at
the same time every day.
5.
You�ll be less likely to "blow off" your workout when it�s out of the
way early (like when you�re exhausted after work or when friends ask
you to join them at the pub for happy hour).
6. You can always "make
time" for exercise by setting your alarm earlier in the morning.
7. It increases your
metabolic rate for hours after the session is over.
Of
all these benefits, the post-exercise increase in your metabolic rate
is one of the most talked about. Scientists call this "afterburn"
effect the "excess post-exercise oxygen consumption" or EPOC for short.
Looking only at the
number of calories and the type of calories burned during the
session doesn�t give you the full picture. You also need to look at the
increased number of calories you continue to burn after
the workout is over. That�s right - work out in the morning and you
burn calories all day long. Imagine burning extra fat as you sit at
your desk at work! That�s the good news. The bad news is, the degree of
EPOC is not as great as most people think. It�s a myth that your
metabolism stays elevated for 24 hours after a regular aerobic workout.
That only happens after extremely intense and/or prolonged exercise
such as running a marathon.
After
low intensity exercise, the magnitude of the EPOC is so small that its
impact on fat loss is negligible. Somewhere between 9 and 30 extra
calories are burned after exercise at an intensity of less than 60-65%
of maximal heart rate. In other words, a casual stroll on the treadmill
will do next to nothing to increase your metabolism.
However, EPOC does
increase with the intensity (and duration) of the exercise. According
to Wilmore and Costill in "Physiology of Sport and Exercise,"
the EPOC after moderate exercise (75-80%) will amount to approximately
.25 kcal/min or 15 kcal/hour. This would provide an additional
expenditure of 75 kcal that would not normally be calculated in the
total energy expended for that activity. An extra 75 calories is
definitely nothing Earth shattering. However, it does add up over time.
In a year that would mean (in theory) you would burn an extra 5.2 lbs
of fat from the additional calories expended after the workout.
One
way to get a significant post exercise "afterburn" is high intensity
interval training (HIIT). HIIT is done by alternating brief periods of
high intensity work (85% or more) with brief periods of lower intensity
work. Studies on the effects of HIIT have demonstrated a much higher
EPOC, which can add substantially to the day�s calorie expenditure. In
one study, scientists from the University of Alabama compared the
effects of two exercise protocols on 24-hour energy expenditure. The
first group cycled for 60 minutes at a moderate intensity. The second
group performed HIIT, cycling for two minutes at high intensity
followed by two minutes at a low intensity. The group that performed
the HIIT burned 160 more calories in 24 hours than the low intensity
group. That means the HIIT group would burn an extra 11.8 pounds of fat
in one year if they did HIIT five days a week instead of conventional
training.
Ironically,
weight training has a much higher magnitude of EPOC than aerobic
training. Studies have shown increases in metabolic rate of as much as
4-7% over a 24-hour period from resistance training. Yes - that means
bodybuilding does burn fat � albeit through an indirect mechanism. For
someone with an expenditure of 2500 calories per day, that could add up
to 100 - 175 extra calories burned after your weight training workout
is over. The lesson is simple: Anyone interested in losing body fat who
is not lifting weights should first take up a regimen of bodybuilding,
then � and only then � start thinking about the morning cardio!
A
common concern about doing cardio in the fasted state, especially if
it�s done with high intensity, is the possibility of losing muscle.
After an overnight fast, glycogen, blood glucose and insulin are all
low. As we�ve already concluded, this is an optimum environment for
burning fat. Unfortunately, it may also be an optimum environment for
burning muscle because carbohydrate fuel sources are low and levels of
the catabolic stress hormone cortisol are high. It sounds like morning
cardio might be a double-edged sword, but there are ways to avert
muscle loss.
All
aerobic exercise will have some effect on building muscle, but as long
as you don�t overdo it, you shouldn�t worry about losing muscle. It's a
fact that muscle proteins are broken down and used for energy during
aerobic exercise. But you are constantly breaking down and
re-building muscle tissue anyway. This process is called "protein
turnover" and it�s a daily fact of life. Your goal is to tip the scales
slightly in favor of increasing the anabolic side and reducing the
catabolic side just enough so you stay anabolic and you gain or at
least maintain muscle.
How
do you build up more muscle than you break down? First, avoid excessive
cardio. Aceto suggests limiting your cardio on an empty stomach to 30
minutes, and then it would be "highly unlikely that amino acids will be
burned as fuel." He also mentions that "a strong cup of coffee should
facilitate a shifting to burn more fat and less glycogen. If you can
spare glycogen, you�ll ultimately spare protein too." You might also
want to consider experimenting with the thermogenic
ephedrine-caffeine-aspirin stack (or it�s herbal equivalent).
Second,
give your body the proper nutritional support. Losing muscle probably
has more to do with inadequate nutrition than with excessive aerobics.
Provide yourself with the proper nutritional support for the rest of
the day, including adequate meal frequency, protein, carbohydrates and
total calories, and it�s not as likely that there will be a net loss of
muscle tissue over each 24-hour period.
Third,
keep training with heavy weights, even during a fat loss phase. Using
light weights and higher reps thinking that it will help you get more
"cut" is a mistake: What put the muscle on in the first place is likely
to help you keep it there.
Still
petrified of losing your hard-earned muscle, but you�d like to take
advantage of the fat-burning and metabolism-boosting effects of morning
cardio? One strategy many bodybuilders use is to drink a protein shake
or eat a protein only meal 30-60 minutes prior to the morning session.
The protein without the carbs will minimize the insulin response and
allow you to mobilize fat while providing amino acids to prevent muscle
breakdown.
In
conclusion, it seems that morning cardio has enough indisputable
benefits to motivate most people to set their alarms early. But let�s
talk bottom line results here: Does it really result in more "real
world fat loss" than aerobics performed at other times of the day or
after eating? I have to believe it does. Experience, common sense and
research all tell me so. Nevertheless, this will obviously continue to
be an area of much debate, and clearly, more research is needed. In the
meantime, while the scientists are busy in their labs measuring
respiratory exchange ratios, caloric expenditures and rates of
substrate utilization, I�m going to keep waking up at 6:00 AM every
morning to get on my Stairmaster.
References
1. Aceto, Chris. Everything
you need to know about fat loss. Club Creavalle, Inc. (1997).
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post-exercise oxygen consumption � Magnitude, Mechanisms and Practical
Implications. Acta Physiol Scand. Suppl. (1992) 605. 1-70.
3.
Bergman, BC, Brooks, GA. Respiratory gas-exchange ratios during graded
exercise in fed and fasted trained and untrained men. Journal of
Applied Physiology. (1999) 86: 2.
4. Brehm, B.A., and
Gutin, B. Recovery energy expenditure for steady state exercise in
runners and non-exercisers. Medicine and Science in Sports and
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5. Brybner, BW. The
effects of exercise intensity on body composition, weight loss, and
dietary composition in women. Journal of American College of
Nutrition, (1997) 16: 68-73
6. Landry, Greg. The
Metabolism System for Weight Loss. Greg Landry. (2000).
7.
Maehlum, S., etc al. Magnitude and duration of post exercise oxygen
consumption in healthy young subjects. Metabolism (1986) 35 (5):
425-429.
8. McCarty, MF.
Optimizing Exercise for Fat Loss. Medical Hypothesis. (1995)
44: 325-330
9. McDonald, Lyle. The
Ketogenic Diet. Morris Publishing, (1998).
10. Melby, C. et al.
Effect of acute resistance exercise on post exercise energy expenditure
and resting metabolic rate. J Applied Physiology, (1993). 75:
1847-1853
11. Wilmore, Jack,
Costill, David. Physiology of Sport and Exercise. (1999) 2nd
ed. Human Kinetics
12. Tremblay, A, et al,
Impact of exercise intensity on body fatness and skeletal muscle
metabolism. Metabolism (1994) 43: 818-818
13.
Treuth, M.S., Hunter, G.R., & Williams, M. Effects of exercise
intensity on 24-h energy expenditure and substrate oxidation. Medicine
and Science in Sports & Exercise. (1996) 28, 1138-1143
14.Wilcox, Harford &
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