Sports
Nutrition For the New Millennium: An Exclusive Report from Las Vegas
by Greg E. Bradley-Popovich, DPT, MSEP, MS, CSCS
Sin
City was recently host to the 25th National Strength & Conditioning Association
conference. I was told the only thing hotter than the triple-digit temperatures
was the lap dancing. Temptations aside, of particular interest to ASMJ readers
would be the pre-conference symposium entitled Sports Nutrition for the New Millennium.
An entire day devoted to intense and cutting-edge discussions on performance supplements—and
yours truly was there to provide ASMJ readers with detailed coverage!
The symposium featured among it some of the top sports supplement authorities
in the country: Jeff Stout, PhD, Jose Antonio, PhD, EPC, Jeff Volek, PhD, RD,
Tim Ziegenfuss, PhD, Richard Kreider, PhD, EPC, and Tom Incledon, MS, RD. The
attendees were astute and accomplished as well, including former IFBB pro and
Arnold Schwarzenegger Classic champion Mike Ashley.
Unlike many stuffy
scientific conferences where speakers would likely be stoned to death for going
out on a limb by actually recommending supplements, the relaxed, intimate environment
at this symposium was ideal for progressive thinkers. The supplement experts had
little reservation in speculating about the practical applications of ergogenic
substances.
Dr. Stout welcomed attendees and laid the foundation for
the following presenters. Dr. Stout emphasized that sports nutrition supplements
are a training aide and are not a replacement for proper training or sound nutrition.
It has been said that a poor diet with supplementation is still a poor diet. Laying
this foundation may have been an act of self-preservation, given that a fist fight
between pro-food and pro-supplement factions threatened to break out among the
audience at a similar symposium two years ago! Regardless of how people perceive
the role of supplementation, I can verify that the presenters did indeed eat real
food during lunch break, though I am sworn to not divulge the contents.
Given the highly qualified speakers, the symposium covered a lot of ground. The
experts discussed and dissected approximately 50 different supplements, not to
mention all the information pertaining to dietary manipulation of macronutrients.
I will try my best to deliver a timely summary while doing the symposium justice.
Get ready, ‘cause the bulleted phrases are gonna fly!
First off,
Dr. Volek of the University of Connecticut presented a lecture entitled “Nutritional
Needs for Strength Athletes.” In it, Dr. Volek reminded us to not ignore
past research, but he certainly did address the latest developments in the dynamic
field of sports nutrition. Some of the more important points he addressed are
concisely provided as follows:
-dietary composition does affect fuel
utilization preference (e.g., the more fat you eat, the greater the percent fat
utilized for energy).
-vegetarian diets lead to a marked decrease in testosterone
compared to an equivalent amount of protein from animal sources.
-muscle glycogen
returns to 90% of baseline if carbohydrate is provided immediately following exercise;
glycogen can return to normal in one day if carbohydrates are consumed in the
amount of 7g/kg bodyweight.
-if you want to consume extra calories to build
muscle mass, choose protein or fat sources because they exert endocrinological
effects by increasing testosterone and growth hormone.
-just a 2 hour delay
in post-workout nutrient consumption may decrease acute training adaptation (i.e.,
compromise your recovery and growth).
-eating protein is insufficient to grow
muscle; a training stimulus is an absolute must.
-if periodizing your training
program, you should periodize your nutrition program to meet the changing physiological
needs of the various training phases.
-L-carnitine shows promise as a means
of reducing muscle damage.
-optimum protein intake is as follows:
o endurance
athletes—1.2-1.4 g/kg bodyweight/day
o strength athletes—1.7-1.8
g/kg bodyweight/day
Next up was the soon-to-be “Doctor”
Tom Incledon of Human Performance Specialists who presented “Optimum Nutrient
Timing: When and What to Eat to Enhance Training Adaptations.” Readers may
recognize Tom as a regular contributor to this magazine. Tom took about a three-hour
lecture and squeezed it into a one-hour slot. This lively presentation was filled
with humorous anecdotes from Tom’s experience as both a strength athlete
and advisor to athletes worldwide. His major points--of which there are many--are
presented here:
Anabolism & Muscle Damage
-
lifting weights increases protein synthesis even more than insulin; amino acids
may increase protein synthesis to an even greater extent (200% increase in anabolism).
- only the essential amino acids (of which there are 10) are required to upregulate
protein synthesis.
- the addition of 35g of simple sugars to post-workout
essential amino acids may further increase protein synthesis rates by 400%; note
this is a very potent anabolic effect from 164 Calories!
- this anabolic concoction
is even more anabolic when taken before a workout
- studies addressing outcome
measures of such synergistic concoctions have failed to demonstrate increases
in strength or lean body mass over 6-10 weeks; the researchers acknowledge that
longer studies (up to 20 weeks) are likely required to detect a benefit.
-
research on vitamin E is in disagreement regarding its ability to reduce muscle
damage associated with exercise; larger doses up to 1200 International Units per
day may be required.
- supplemental branched-chain amino acids (BCAAs) appear
to reduce muscle damage related to endurance exercise, even when plenty of BCAAs
are present in the diet.
- beta-hydroxymethylbutyrate (HMB) at a dose of 3g/day
is apparently most effective at reducing muscle damage in previously untrained
persons.
- after years of getting no respect, L-carnitine at a dose of 3g/day
shows new promise as a means of reducing pain and markers of muscle damage.
Pre-workout Supplementation
- pre-exercise carbohydrates
with a low glycemic index should be ingested at 1-2 g/kg body weight one hour
prior to exercise.
- glutamine attenuates the catabolic hormone cortisol when
cortisol levels are very high and is especially beneficial when a diet is low
in glutamine.
- phosphatidylserine appears to lower cortisol levels at 800
mg/day, but the safety of this supplement has yet to be fully elucidatedover long-erm
use.
- preliminary research shows acetyl-L-carnitine to increase testosterone
in males, and an initial dose of 2 g/day is recommended with this compound, which
possesses a good safety profile.
Nutrition During Exercise
- a 5-10% solution containing 15-20 g of carbohydrates consumed during endurance
activity has repeatedly been shown to increase endurance.
- athletes are using
2-5 g each BCAAs and glutamine for the rationale previously outlined; there is
no scientific evidence as yet that this is effective, but it makes sense that
it would work similarly and would not need to be repeated postworkout..
Post-workout
Supplementation
- consume high glycemic index foods or supplements immediately
following exercise in the amount of 0.7-1.0g per kg body weight every 2 hours
for 4-6 hours.
- if consuming BCAAs before or during exercise, no need for
specific supplementation afterwards.
- the ideal time for creatine supplementation
is immediately following a workout (5g).
Dr. Richard Kreider
of Baylor University delivered a very practical lecture called “Effective
Ergogenic/Nutritional Aids to Promote Muscle Gain and Fat Loss.” Dr. Kreider
is one of the most widely published scientists in the field of sports nutrition,
and here is a sample of his wisdom, arranged according to his views on product
effectiveness:
Apparently Effective Supplements
weight gain powders—pack on mass but only 30-50% of the
weight gain is muscle, with the remainder as fat; carbohydrate intake for weight
loss is very different than for normal training (5-8 g/kg bodyweight/day).
creatine—expect to gain 2-5 pounds of lean mass during
4-12 weeks of training; there are now over 500 studies examining the physiological
and performance effects of creatine; a forthcoming three-year study on creatine
safety by Dr. Kreider fails to show any negative health effects on a number of
variables, and creatine actually decreases the incidence of musculoskeletal injury.
beta-hydroxy beta-methylbutyrate (HMB)—1.5-3 g per day
appears to increase lean mass by 0.5-1 kg, decrease muscle damage and catabolism
over 3-6 weeks of training; problem is, this appears to be true only of previously
untrained subjects; the cost-to-benefit ratio of HMB is clearly inferior to creatine.
Possibly Effective Supplements
Branched chain amino acids (BCAAs)—are
anticatabolic with respect to effects on protein synthesis, muscle damage, and
hormones; BCAAs are particularly useful when training at altitude; research has
shown improvements in muscle mass and grip strength in just one month when BCAAs
were consumed in the amount of 14 g/day.
Essential amino acids (EAAs)—consuming
10 to 20 g of EAA both prior to and following exercise is highly anabolic with
respect to protein synthesis; research findings indicate that consuming EAA and
carbs immediately after strength training allowed significantly enhanced training
adaptations as compared to consuming the same formula two hours post-exercise.
Glutamine—increases cell volume, protein synthesis, and
glycogen synthesis; 5 g of glutamine plus 3 g BCAAs in an enriched whey protein
supplement has been shown to increase muscle mass by an extra two pounds when
compared to whey protein alone.
Too Early to Tell
Alpha-ketoglutarate—anticatabolic
after surgery, but role in improving muscle gain during exercise lacking in data.
· Alpha-ketoisocaproate (KIC)—again, possibly effective in a hospital
setting, but evidence in exercising people is lacking.
Ecdysterones—are
actually insect hormones that have little reputable research on effects in animals,
and of course there are no data in strength-trained humans.
Ornithine
alpha-ketoglutarate (OKG)—effective in the hospital but not as
impressive in the gym; one study shows a modest effect in weight-trained persons
in improving strength at a dose of 10 g/day.
Zinc/magnesium aspartate
(ZMA)—one study in football players shows this compound to enhance
testosterone and IGF-1 levels and consequently strength; Dr. Kreider believes
these findings need additional support
Following Dr. Kreider
was the final speaker, Dr. Tim Ziegenfuss, who is affiliated with Kent State University.
This tell-it-like-it-is presentation addressed banned and/or ineffective nutritional
ergogenic aids. Among Dr. Ziegenfuss’ points were the following:
Many coaches and athletes profess “statistics be damned” because even
the slightest improvement in performance--however “insignificant”
it may be to a statistician—can mean the difference between winning and
losing among elite athletes.
Dehydroepiandrosterone (DHEA)—testosterone
precursor shown to not be effective at fat loss or muscle gain in all but one
study; no studies have tested DHEA in athletes.
Testosterone boosters—typical
variations of androstenedione or androstenediol, as well as the nor- varieties
have been a bust; there are no data to suggest ergogenic effects in athletes or
nonathletes; the latest androgen precursors have been modified to enhance sublingual
absorption and to decrease chemical breakdown by the liver.
ZMA—one
study shows an ergogenic effect, but this may explained by addressing a prior
mineral deficiency.
Avena sativa—supplement that is
thought to increase free testosterone, but which is lacking supportive data
Ephedrine—over-the-counter status varies by state; at a
dose of 1 mg ephedrine/kg bodyweight and 5 mg caffeine/kg body weight, improvements
occur in aerobic and anaerobic performance
Myostatin inhibitors—substances
designed to bind the myostatin protein that suppresses muscle growth; an exciting
possibility, but be skeptical of such products that are presently being marketed
because they have not been independently scientifically evaluated.
Supplements
should be “the icing on the cake”
First, plan your diet out to
meet energy, macronutrient (e.g., protein, carbs, fat, fiber) and micronutrient
(e.g., vitamins and minerals) needs; then consider supplementation.
Of mainstream
strategies, post-workout carbohydrate/protein meals or supplements, creatine,
and caffeine are reliable ergogenics.
The finale for this
sports supplement extravaganza was a question and answer session with all of the
panelists. The supplement experts fielded questions on a variety of topics, with
a few of the major issues as follows:
Ephedrine and herbal equivalents—while
not all panel members agreed that ephedrine or its herbal sources is the ideal
fat-loss supplement for everyone, the panel seemed to concur that this class of
supplements was relatively safe and effective; the speakers pointed out that there
are more adverse event reports (which has created the majority of bad press for
ephedrine et al.) associated with vitamin E than with ephedrine-containing supplements.
Chocolate milk—perhaps to the surprise of many attendees,
on more than one occasion chocolate milk was promoted as a great post-weighttraining
beverage, especially if in a pinch. Hey, it’s got casein and whey proteins
to slow protein degradation and to boost protein anabolism, respectively. Plus,
it has simple carbs to replenish glycogen stores.
Glycemic index (GI)—indeed,
the disctinction of carbohydrates based on molecular structure (e.g., simple vs.
complex) is going by the way of the dinosaur in favor of the glycemic index, which
is based on the physiological effects of various carbohydrates. In agreement with
conventional recommendations, the pre-workout meal about an hour before a workout
should be comprised of protein and low glycemic carbs, and the postworkout meal
should provide protein and high glycemic carbs. A glycemic index search engine
is now available at www.glycemicindex.com where you can plug in a food and find
out its GI.
·Creatine—the shelf-life of dry
creatine supplements is about 2 years. To assist in dissolving powdered creatine,
it’s OK to add creatine to a hot beverage because creatine is relatively
stable under such conditions. None of the panelists believed the popular notion
(which has some scientific evidence to support it) that caffeine negates the ergogenic
effects of creatine under normal circumstances.
Despite
the excellent organization by moderators Drs. Antonio and Stout, one can only
address so much information in a six-hour venue. One subject that did not receive
its deserved level of attention was the resurrection of casein protein as a very
valuable protein supplement for building mass. I am aware that at least some of
the panel are proponents of casein, and if time had permitted casein would likely
have been endorsed as the protein of choice because of its prolonged anticatabolic
activity.
Another subject that did not receive much attention was that of
new prohormone preparations using novel molecular tweaks to maximize bioactivity
or conversion into bioactive hormones such as testosterone. The lack of conversation
in this area was a bit surprising given that Drs. Antonio and Ziegenfuss are known
for their work on this topic. I attribute this lack of discussion to the fact
that the audience was largely comprised of coaches, and prohormones are banned
by many sports organizations. In addition, it is difficult for university-sponsored
research to keep pace with new molecular variants of prohormones.
The
ever-controversial Dr. Antonio, who has a habit of being quoted for his outspokenness
on sports supplements and his unconventional views on anabolic steroids, was relatively
benign. But, his colleagues were sufficiently outspoken to compensate.
So what was the grand lesson to take home from Gambleville? Don’t leave
your nutrition and supplement program to chance! Be deliberate and methodical;
if you find time to train, you should find time to eat and supplement properly.
Read this information-packed article again and again so that you can digest and
implement the nutrition strategies discussed herein.
About
the Author
Dr. Greg Bradley-Popovich holds dual master's degrees
in Exercise Physiology and Human Nutrition from West Virginia University as well
as a Doctor of Physical Therapy degree (DPT) from Creighton University. In 2001,
Greg received the top honor in the United States for a graduating physical therapy
scholar from the American Physical Therapy Association. For his scholarly approach
to strengthening and conditioning, Greg has also been recognized by the National
Strength and Conditioning Association and the International Association of Resistance
Trainers. He has published dozens of popular and scholarly articles on a variety
of topics, including a chapter in the new textbook Sports Supplements (available
at www.lww.com). He is the Director of Clinical Research at Northwest Spine Management,
Rehabilitation, and Sports Conditioning in Portland, Oregon.