Most people know not to eat a gallon of Ben and Jerry’s before
an intense workout and that drinking water to hydrate a sweating
body is good. That guidance is okay as far as it goes, but operating
a complex machine such as the human body with only a meager list
of such maxims is akin to feeding a racehorse Mountain Dew and cheesecake
so he’ll speed from the sugar—you can do better.
Dr. John Ivy, chairperson of the Department of Kinesiology and
Health Education in the College of Education at The University of
Texas at Austin, has spent the past thirty years looking at simple,
healthy options for building strength, endurance and muscle mass.
What he has discovered is that timing is everything.
For decades, serious athletes as well as hard-pushing weekend warriors
have searched for the holy grail of exercise nutrition, following
one trend after another in an effort to capture the magic formula
that increases strength, endurance and lean muscle mass.
Conventional wisdom in the late 1960s and early 1970s pointed to
carbo-loading as a way to super-saturate muscles with carbohydrate
and fuel cross-country skiers as well as long-distance runners and
endurance cyclists. For strength athletes, that paradigm was flipped
on its head and protein intake was stressed.
With each new wave of information and fad-following, the one element
that often seemed to be missing was strong, conclusive scientific
When Ivy, a world-renowned expert on the role of nutrition in exercise
performance, began to study the maximization of physical performance,
his research concentrated on the cellular level and a somewhat overlooked
element of nutrition—timing. His goal was to explain, in scientific
terms, why an athlete sees particular effects when she supplements
at specific times with certain nutrients.
“When you exercise,” says Ivy, “the muscles become
very sensitive to certain hormones and nutrients, and you can initiate
many highly desirable training adaptations if you make sure the
correct nutrients are present. This increased sensitivity of the
muscles only lasts for a limited length of time, so the element
of time becomes absolutely crucial. If you miss this window of opportunity,
there’s no way you can stimulate the muscle adaptations to
that extent until after the next bout of exercise.”
To understand Ivy’s breakthrough findings, it’s helpful
to revisit Biology 101 and look at the delicate, elaborate symphony
of hormone activity and energy replenishment occurring behind the
scenes when you run, swim, power-lift, ski or cycle.
with any good high-performance product, a contracting muscle needs
fuel. Adenosine triphosphate (ATP) is the only energy source that
can drive muscle contraction, but, like a car that gets two miles
to the gallon, muscles can only store enough ATP for a few seconds
of high intensity contraction. If muscle contraction is going to
be sustained, and you want to keep sprinting or pedaling up a steep
incline, the muscle needs this ATP to be continuously replenished.
Fortunately, the body has ways of generating more ATP and keeping
the marathon-runner running and the soccer player blocking goals.
Through the anaerobic pathway, glycogen and creatine phosphate rush
to provide rapid energy for intense bursts of activity as you speed
from third base to home plate. Through the aerobic pathway, fat,
carbohydrate and protein fill the void and are used to provide sustained
energy with much more efficiency than the anaerobic pathway.
As systems scramble to meet the muscles’ appetite for ATP,
wear and tear on the body can occur, leaving you tired, dehydrated
and with reduced blood volume, a compromised immune system and muscle
damage. The degree of the negative effects correlates with the intensity
and duration of exercise.
“What we found in our studies,” says Ivy, “is
that you can recover more effectively, work out harder more frequently,
increase muscle mass and enhance the physical adaptations that are
happening when you exercise just by minding what supplements you
use and when you supplement.”
Ivy tested distance runners, triathletes and strength athletes
between the ages of 19 and 35, hoping to determine what allowed
for the fastest recovery of muscle glycogen, a key fuel for contracting,
that have a 4:1 carb/protein ratio improve endurance, reduce
muscle damage and speed recovery after exercise.
When the athletes ingested a carbohydrate supplement immediately
after exercise, they had a much higher rate of glycogen recovery,
which is fuel for the muscle, than if the supplement was delayed
for several hours. Ivy also discovered that once this fuel storage
process kicked in it could be maintained at a rapid rate if the
individual supplemented at two-hour intervals for up to eight hours
after exercise ended.
Although approximately 1.4 grams of carb per kilogram of body weight
maximized glycogen storage, Ivy found that more of a seemingly good
thing did not end up being better—the rate of glycogen storage
could not be increased with an increase in carb intake.
The surprising addition of a limited amount of protein, however,
sparked a chain reaction that does a body good.
When protein is added to carbohydrate, the insulin concentration
in the blood rises. Insulin is a facilitator and stimulates glucose
uptake by the muscle and the conversion of glucose into the highly
valuable glycogen, as well as increasing the rate of protein synthesis
when the supplement is taken immediately after exercise.
With his research findings, Ivy identified a span of time during
which exercise and post-exercise nutrition is very important to
the athlete who wants to improve endurance, reduce muscle damage,
maintain immune function and jumpstart a much quicker recovery.
According to Ivy, “nutrient timing” begins 30 minutes
before exercise, when one should fully hydrate and raise blood glucose
levels by consuming approximately 14-20 ounces of water or electrolyte
solution. This delays the development of dehydration, hastens the
onset of sweating and moderates the rise in body temperature.
During exercise, smart nutrition choices become even more important.
In order to spare muscle glycogen, limit cortisol and free radical
levels, prevent dehydration and set the stage for faster recovery
after a workout, Ivy found that fluids should be replenished every
15 to 20 minutes, if possible.
one study with cyclists, Ivy discovered that drinking a fluid containing
carbohydrate and protein in a 4:1 ratio improved endurance 57 percent
compared with water and 24 percent compared with a carbohydrate
Because muscle breakdown occurs faster during exercise, consuming
a supplement that includes protein while exercising gives muscles
some of the protein they need to produce extra energy. The result
is less muscle damage. Similarly, maintaining blood glucose levels
by ingesting carbohydrates during exercise leads to less depletion
of glycogen stores and less fatigue.
Wrapping up the metabolic window of opportunity around exercise
is the very important 30 minutes following a workout. In fact, according
to Ivy, this is the most important time for minding nutrition
p’s and q’s.
In the 30 minutes following a workout, a muscle’s potential
to rebuild peaks, and it is extremely sensitive to insulin. To take
full advantage of the muscle rebuilding benefits that can occur
in this golden window of opportunity, the right combination of nutrients,
such as carbohydrate and high quality protein, should be consumed
within 15 to 45 minutes after exercise.
Insulin sensitivity, and the ability of muscle fibers to pack in
as much energy as possible, falls significantly one hour after exercise.
After two hours, muscles not only lose their sensitivity but actually
become insulin resistant and muscle breakdown occurs. Even though
activity has stopped, the muscles continue to lose protein and nutrients
“Paying attention to what you eat or drink and when you consume
it is a lot easier, cheaper, healthier and safer than using some
plant steroids, androstenedione or creatine supplementation, for
example,” says Ivy. “Just following a good basic diet
and supplementing at the right time may not sound all that exciting,
but solid scientific research says it works and yields increases
in muscle mass, strength and endurance. It can even protect your
immune system and keep you from getting as many colds and upper
should begin 15 to 45 minutes after exercise ends or you risk
missing the metabolic window of opportunity.
Ivy’s pioneering findings in the area of sports nutrition
are presented in his two latest books, “Nutrient Timing”
and “The Performance Zone,” which he co-authored with
Dr. Robert Portman, president and director for PacificHealth Laboratories.
With “Nutrient Timing,” the guidance is geared to strength
athletes and bodybuilders. In it, Ivy emphasizes that attention
to timing and nutrition during the muscles’ 24-hour growth
cycle can help weight trainers break through plateaus, increase
muscle mass and suffer less soreness and stiffness after workouts.
“The Performance Zone” serves as a sports nutrition
action plan and workbook for all levels of athletes, with sports-specific
information from Olympic swimmers, exercise physiologists, world
champion triathletes and professional sports stars. In order to
encourage amateurs as well as more serious exercise enthusiasts
to implement nutrient timing, the book includes, among other things,
information on calculating the number of calories expended during
different types of exercise, how to determine fluid and nutrient
needs during exercise and a comparison of the many sports drinks
on the market. The specific needs of female athletes as well as
active children also are addressed.
“At any given time, there’s a lot of information out
there about how to train better,” says Logan Schwartz, an
Austin strength conditioning coach who trains professional as well
as high school and college athletes. “But there’s not
much good information. Dr. Ivy’s nutrient timing
system, which I and my clients use, stands apart because when you
look behind the claims you find valid scientific research. Attention
to nutrition as a vital part of improving physical performance is
really a fairly new, revolutionary thing, and it’s turning
out to be very important.”
as dehydration increases, quality of performance will continue
Although Ivy now finds himself talking to reporters and interested
groups from coast to coast about nutrient timing, sports nutrition
might be described as something of a second love. For the past 30
or more years the bulk of his research has been devoted to diabetes
and, most specifically, the effects of exercise on diabetes.
“One thing we discovered that’s very significant,”
says Ivy, “is that muscle contraction, which happens when
you exercise, increases glucose uptake differently from the way
that insulin increases glucose uptake. Diabetics who are insulin-resistant
have muscles that cannot efficiently take up glucose by insulin
stimulation, but the muscle will take up glucose in a normal manner
with muscle contraction. That means you can help regulate blood
glucose levels through exercise. That’s good news and a natural
way to address the problem.”
Having spent his professional career studying exercise and nutrition,
one would expect Ivy to practice what he preaches. And he does.
A former college baseball player, he is trim and athletically built,
with an office ringed in pictures of his trim, muscled and athletic
children, one of whom is test-driving the nutrient timing system
along with Ivy.
Glancing at Ivy and the photos of his cheerleading, baseball-playing
progeny, you might be tempted to argue that the family simply enjoys
good genes. But that’s like watching the smooth, perfect arc
of a Tiger Woods swing and saying he’s just awfully lucky
again and again—you’re ignoring the importance of hard
work…and good timing.