CYCLING
PERFORMANCE TIPS
Protein
Protein is used to repair cell injuries
(muscles particularly) from the microscopic trauma that occurs with
exercise. It is NOT a good energy source, and serves that purpose
only in malnourished states. Even in endurance activities such as the
Tour De france, protein needs of 1.5 gms protein/kg body wt/day were
easily met by a normal (read unsupplemented) diet that replaced the
total Calories used each day.
All protein
molecules are composed of building blocks called amino acids. Most
protein digestion occurs in the small intestine where protein
molecules are first split into their component amino acids which are
then absorbed by the intestinal lining, transported via the
circulatory system, and taken up by cells throughout the body. These
amino acids are then used to rebuild cell proteins. Any excess
protein in the diet is transformed (metabolised) into carbohydrates
(gluconeogenesis) or fat. Protein itself is not stored in the body
which means cell repair occurs from protein eaten that day or from
amino acids released as protein is broken down elsewhere in the body.
HOW MUCH PROTEIN DO YOU REALLY NEED?
A team of
researchers from Kent State University, Ohio, and McMaster
University, Ontario, led by Dr. Peter Lemon studied a group of 12
male subjects during two months of resistance training. They found
that a protein intake of 81 grams per day (0.99g per kg of bodyweight
for a 180 lb male) resulted in a negative nitrogen balance. Nitrogen
balance is a measure of protein metabolism. A negative nitrogen
balance indicates that the protein needs of the body are not being
met and protein is being scavanged from tissue elsewhere in the body
to maintain essential body functions. This may lead to reduced gains
in muscle mass and strength.
Can you eat too
much protein? This group also found that protein intakes above 2.62
grams per kg of bodyweight (214 grams for a 180lb male) provided no
additional benefit in terms of nitrogen balance and increased the
risk of renal overload and dehydration. Long term studies of large
groups show that a high protein/low carbohydrate diet increases the
risk of kidney stones and bone loss. These findings were
substantiated by a University of Texas study of 10 volunteers on a
high protein/low carbohydrte diet for two weeks. Blood uric acid
levels (uric acid is a major cause of kidney stones) rose 90% and
urinary levels of citrate (which inhibits kidney stone formation)
dropped 25%. And finally, any extra protein Calories (beyond what you
are expending per day) are stored as fat, not muscle.
Protein is
essential for endurance athletes as well as to aid muscle
development. As far back as 1983, scientists demonstrated that two
hours of exercise can drain the body of essential protein stores.
Based on their findings, Dr. Lemon makes the following
recommendations for protein intake for strength and endurance
athletes:
The average 70 kg (154 pound) cyclist
will need from 80 to 100 grams of protein per day. And for those at
the elite level, the requirement may be as high as 1.7 grams of
protein per kgm (120 grams for the ideal 70 kg rider). And as active
athletes consume more daily Calories, a balanced diet without
supplements will meet these increased needs.
A literature
review failed to find any support for protein supplements (assuming a
balnaced daily diet with the normal distribution of protein intake)
compared to a pure carbohydrates diet alone. In fact there is the
potential for a DECREASE in overall performance from the
appetite suppressing effects of a high protein diet which results in
a decrease in carbohydrate intake and diminished pre event muscle
glycogen stores.
SOURCES OF PROTEIN
Lean beef, skinless chicken, and fish
will provide about 7 grams of protein per ounce. Beans will provide 6
grams per 1/2 cooked cup, and rice (and other cereal grains) about 3
grams per 1/2 cup serving. A cup of milk or yogurt supplies 8 grams
of protein. So it's relatively easy to meet your basic protein
requirements from 6-8 ounces of meat, 2-3 servings of dairy products,
and 6-10 servings of cereal per day.
A HIGH PROTEIN DIET (THE ZONE DIET)
The ZONE is
basically a Calorie restricted, high protein diet used to facilitate
weight loss. It has also been proposed as a nutrition strategy to
improve athletic performance, reduce body fat and increase muscle
mass. It recommends consuming 40% of your daily Caloric intake in the
form of carbohydrate, 30% as protein, with fat making up the other
30%. An analysis should give us some insight into the effects of a
high protein diet.
If you are a 60
kg (132 pound) cyclist requiring 3000 Calories per day for your
training program, a recommendation of 1.5 grams would translate into
90 grams of protein or 10-12% of your overall Calories (there are 4
Calories per gram of protein). However to reach 30% protein, you'd
need to consume a massive 225 grams.
Here's what
you'd need to eat each day:
1 cup cottage
cheese-----28 grams
1 can (3oz) tuna fish----22 grams
3 glasses milk-----------24 grams
8 ounces lean beef-------66 grams
1 cup kidney beans-------13 grams
1/4 cup peanut butter----32 grams
1 chicken breast---------27 grams
3 egg whites-------------12 grams
TOTAL-------------------224
grams
However, Dr. Sears doesn't start
with your Calorie needs (remember this is a Calorie restricted diet).
He starts with your weight and then calculates you protein
requirements. Dr. Sears recommends consuming between 0.8 and 1.0g of
protein per pound of lean body mass. For an individual weighing
180lb, daily protein intake would work out between 127g and 158g per
day. As he recommends that protein represent 30% of daily caloric
intake, daily fat consumption (30% of Calories) works out to be 70g,
and carbohydrate (40%) is 211g. The daily energy content of the Zone
diet for this 180lb individual is approximately 2106 Calories. And
that is how it helps you lose weight - the total Calories consumed
using this approach is much less than an active athlete needs.
What are the
problems with the Zone diet diet for an athlete? As just pointed out,
the recommended carbohydrate intake for our 180lb rider was 211g of
carbohydrate per day. Such a recommendation is in sharp contrast to
the majority of scientific research which proves the need for
adequate carbohydrate to support maximal physical performance.
For example, a
recent study compared the effects of different levels of carbohydrate
intake on the performance of two Swedish ice hockey team. Both teams
took part in two games separated by three days. During this three-day
gap, the players were assigned to one of two groups. The first group
consumed a normal mixed diet that provided around 40% of energy from
carbohydrate. Group two had their diet supplemented with extra
carbohydrate. Energy from carbohydrate in the second group
represented 60% of total energy intake. The study clearly showed an
improvement in physical performance in the high carbohydrate group.
Simply put, a diet containing only 40% of its calories from
carbohydrate was insufficient to meet the energy needs of elite
athletes.
The Zone diet's
recommendations for daily protein intake are a little closer to the
mark. The amount of protein required by those participating in
regular exercise sessions remains a topic of considerable debate.
Nevertheless, there is research to show that both endurance and
strength exercise increase protein requirements.
But the Zone
diet can accelerate fat loss. While it does not provide enough energy
to meet the needs of a competitive athlete, it does restrict Calories
and its emphasis on high levels of protein may also serve to enhance
fat loss. A recent Danish study, published in the International
Journal of Obesity, compared the effects of a high protein and a high
carbohydrate diet on weight loss. A group of 60 subjects followed a
restricted Calorie diet for six months. The participants were
assigned to either a high carbohydrate or high protein diet. Those on
the high protein diet consumed approximately 24% of their Calories
from fat, 46% from carbohydrate, and 29% from protein. The diet for
subjects on the high carbohydrate diet consisted of 28% from fat, 59%
from carbohydrate, and 12% from protein. Scientists found that the
high protein group lost almost twice as much fat as those on the high
carbohydrate diet.
Notice the
similarity between the nutrient distribution in the high protein diet
(46/29/24) and the recommendations in the Zone diet (40/30/30). The
group following the high protein diet consumed 11.3 Calories for
every pound of bodyweight each day - similar to the 11.7 Calories per
pound of bodyweight suggested by the Zone diet.
After analyzing
the dietary intake of the groups, the research team realized those on
the high protein diet had eaten less food. This accounted for the
greater weight loss. There were several possible explanations for
this reduction in food intake. Protein has a higher satiating
(pronounced effect than carbohydrate. In other words, you feel less
hungry when consuming a diet high in protein. And a high protein
intake seems able to suppress the following days energy intake to a
greater extent than carbohydrate.
The bottom line
- The Zone diet is essentially a restricted calorie diet. For
individuals wanting to lose body fat, there is no reason why the Zone
diet would not prove effective. However it is unrealistic to expect
that athletes will experience any significant improvements in
performance as a result of the Zone diet. The recommendations for
both carbohydrate and Caloric intakes are not sufficient to meet the
energy requirements of regular daily training.Go high protein/low
carbohydrate and you'll be chronically bonked.
WHAT ABOUT PROTEIN SUPPLEMENTS TO A NORMAL DIET?
In his review of
the literature (original abstract) on dietary protein supplements,
Dr. Richard B Kreider PhD (Department of Human Movement Sciences &
Education, The University of Memphis, Memphis, Tennessee 38152.
Email: kreider.richard@coe.memphis.edu) concluded that "dietary
supplementation of protein beyond that necessary to maintain nitrogen
balance does not provide additional benefits for athletes."
Here is an
excerpt of his review:
BACKGROUND
Protein and amino acids are among the most common nutritional
supplements taken by athletes. This review evaluates the rationale
and potential effects on athletic performance of protein, purported
anabolic amino acids, branched-chain amino acids, glutamine,
creatine, and hydroxymethylbutyrate (HMB). LITERATURE. Two books, 61
research articles, 10 published abstracts, and 19 review articles or
book chapters. FINDINGS. Dietary supplementation of protein beyond
that necessary to maintain nitrogen balance does not provide
additional benefits for athletes. Ingesting carbohydrate with protein
prior to or following exercise may reduce catabolism, promote
glycogen resynthesis, or promote a more anabolic hormonal
environment. Whether employing these strategies during
training enhances performance is not yet clear. There is
some evidence from clinical studies that certain amino acids (e.g.,
arginine, histidine, lysine, methionine, ornithine, and
phenylalanine) have anabolic effects by stimulating the release of
growth hormone, insulin, and/or glucocorticoids, but there is little
evidence that supplementation of these amino acids enhances athletic
performance. Branched-chain amino acids (leucine, isoleucine, and
valine) and glutamine may be involved in exercise-induced central
fatigue and immune suppression, but their ergogenic
value as supplements is equivocal at present. Most studies
indicate that creatine supplementation may be an effective and safe
way to enhance performance in intermittent high-intensity exercise
and to enhance adaptations to training. Supplementation with
hydroxymethylbutyrate appears to reduce catabolism and increase gains
in strength and fat-free mass in untrained individuals initiating
training; as yet, limited data are available to decide how it affects
training adaptations in athletes. CONCLUSIONS. Of the nutrients
reviewed, creatine appears to have the greatest ergogenic potential
for athletes involved in intense training. FURTHER RESEARCH. All
supplements reviewed here need more evaluation for safety and effects
on athletic performance.
Potential risks
of excessive dietary protein or protein supplements include:
skimping on
the carbohydrates needed for muscle glycogen repletion (risking the
development of chronic fatigue)
dehydration
potential kidney damage over time
and excessive bone loss (as
protein increases urinary calcium loss).
THE BOTTOM LINE
Protein is
necessary for the active athlete, but more is not necessarily
better. And this is especially so if you replace total Caloric
needs with protein at the expense of carbohydrates.
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