Diet and Athletic Performance

Source: John McDougall, M.D. (http://www.drmcdougall.com/)

For additional information concerning vegetarian, vegan and animal-protein diets see this excellent article by Joel Fuhrman, M.D.

Building Your Own High-Performance Athletic Body
Carl Lewis, the world’s fastest man, is my biggest claim to fame for an athlete who follows the McDougall Diet. (Not too shabby, huh.) He set the world record for the 100-meter dash, won two gold medals, and had the best long-jump series of his career (29 feet three times – these are considered the best series of jumps of all times) while following the McDougall diet.(1) I met Carl Lewis in 1990 in Minneapolis one morning while we were both appearing on a TV talk show. He told me he was frustrated because all previous eating plans had either caused him to become overweight or left him too weak to compete and win (these were mostly low-calorie, portion-control diets). Shortly afterwards he began eating our recommended low-fat, pure-vegetarian diet and his dilemma was resolved. Yes, he discovered there IS a diet that would allow him to look, feel, function, and perform at his best without ever being hungry – shouldn’t that be the way for all of us?
In the introduction to his new cookbook “Very Vegetarian” (written by Jannequin Bennet – Rutledge Hill Press -- released in 2001), he says, “In fact, my best year of track competition was the first year I ate a vegan diet.” He continued, “Dr. McDougall challenged me to make a commitment to eating a vegetarian diet and then to just do it.” Thousands of other world-class athletes have learned to follow a near-vegetarian diet simply because they have no other choice if they want to join the winners’ circle. By the nature of the foods, a winning athlete must eat mostly plants to obtain high-octane fuel (carbohydrate).

Winning at All Costs
Serious competitors would drink cockroach saliva and eat rat droppings to improve their performance by 0.0001%. Fortunately, the winning edge is not so unappealing. All knowledgeable scientists agree that for the best performance during prolonged exercise the best fuel for the body is carbohydrate. In practical terms, this means eating starches (rice, corn, potatoes, beans, pasta, bread), vegetables, and fruits – all of these plant foods contain 70% to 95+% of their calories as carbohydrate. Winning athletes shun foods devoid of meaningful amounts of carbohydrate – these are meat, poultry, fish, eggs, cheeses, and vegetable oils. Therefore, a near-vegetarian diet is necessary for athletes to attain the recommended 60% to 70% of their daily energy as carbohydrate. (2,3)

Except for milk and honey, carbohydrates are found in significant amounts only in plant-derived foods. Even these two foods (milk and honey) obtain their simple sugars originally from plant sources (grasses, grains, and pollen).

Sugar is Energy
There are 3 potential sources of fuel (calories) from our foods – protein, fat, and carbohydrate. Protein is only used as fuel during times of extreme deprivation, such as starvation. Fat is the “metabolic dollar” stored for the day when no food is available (a day which seems to never come). Theoretically, fat can provide fuel for several days of continuous low-intensity activity, and is reserved for use when sufficient carbohydrate is not available. Carbohydrate is the body’s preferred fuel for daily activities and high-intensity exercise performance. Following a low-carbohydrate regime will impair performance. (4,5)

In general, research shows 3 to 4 days of following such a high-fat, high-protein diet is enough to deplete the body of its stores of carbohydrate, clearly impairing short-term performance. (6) The well-known feeling of fatigue results from low carbohydrate reserves in the body. (2) Carbohydrate is another name for sugar. The topic of carbohydrate is so important to human health that there are medical journals, like the Journal of Carbohydrate, and yearly medical symposiums that focus solely on these vital sugars. Some cells in the body, like the red blood cells and filtering cells of the kidneys (glomerular cells), can only use carbohydrate for energy. The brain and other parts of the nervous system have a very strong preference for carbohydrate – burning fat only under extra ordinary circumstances. When sufficient carbohydrate is not available, because of starvation or when someone foolishly follows a low-carbohydrate diet for weight loss, the body then makes carbohydrate from protein (for example, from the body’s own muscle protein). This process occurs primarily in the liver, and is called gluconeogenesis . Fatty acids (fats) cannot be converted to carbohydrate (glucose).

Forms of Carbohydrate
Sugars are divided into complex and simple carbohydrates (sugars). Simple sugars are usually thought of as unhealthy foods – for example, white sugar (sucrose) or high- fructose corn syrup. But simple sugars are also plentiful in sweet-tasting fruits – an important part of a healthy diet. Complex carbohydrates are long branching chains of simple sugars connected together – they are often called starches. This kind of sugar is abundant in common starchy plant foods, like corn, potatoes, rice, whole wheat flours, and beans. Green and yellow vegetables also synthesize and store complex carbohydrate. Glycogen is a form of complex sugar (branching chains of glucose) synthesized in the human body and then stored for use during future strenuous activities. The liver and muscles are the primary depots for glycogen storage. Glycogen resynthesis is maximal – twice as rapid – during the first 2 hours after exercise. (7) Running out of glycogen is described by long-distance runners as “hitting the wall.”

Choose High Glycemic Foods
Athletes have learned to choose foods that have a high glycemic index .* (8,9) You eat in order to replenish your energy supplies – the more efficiently a food raises the blood sugar, the better. High glycemic index foods, such as glucose, rice, potatoes, and bread, result in faster and more efficient storage of glycogen, than do low-glycemic foods, like fructose. Winners need their glycogen stores filled to the brim in order to last the long race. To seek foods with a high glycemic index is good advice for every person wanting to be strong and energetic throughout the day – not just athletes.

* The glycemic index is a measure of how high a sugar level rises and how long it stays up in the blood after eating.

You may have learned that you should avoid foods high in this index because these foods cause the blood sugar to rise, which then leads to diabetes. Nothing could be further from the truth. You may even have heard that candy bars are healthier for you than potatoes and carrots because of the candy bars’ lower glycemic index – how silly (I’m sure you didn’t fall for that one). Populations of people worldwide who eat diets centered on high glycemic index carbohydrates, like rice for rural Asians, and potatoes for people in Peru, are essentially free of diabetes. (10,11) People, living like Americans, choosing foods lower in their glycemic index, those foods which are also high in fat and protein, suffer from an epidemic of diabetes – of both types. (For more on type-1 diabetes – see my July 2002 newsletter, and type-2 – see “Common Diseases, Diabetes” on my web site. Type-2 diabetes is soon to be the subject of a newsletter.)

The More Protein, the Better (Not!)
Athletes and their trainers focus on protein, extolling its benefits for muscle size and power. They encourage unlimited consumption of steaks, chicken breasts, pork chops, and fried eggs. In addition, protein powders are touted as absolutely necessary for even the amateur body builder. Advertisements claim, “You only live once…live large…These supplements make body building easy and fast!”

Protein is necessary for building all tissues in the body, including muscles. However, incorporation of protein into the muscles follows hard work, not “hard eating.” If eating muscle foods (cows, pigs, chickens, and fishes) was crucial for building muscles then all Americans would look like (the much younger) Arnold Schwarzenegger, as a result of the huge amounts of protein they eat everyday. Excess protein is metabolized by the liver and kidneys and excreted out of the body through the kidneys – it is not destined for the muscles. You already know where all that excess protein goes. Recall the pungent smell of the amino acid, asparagine, from your urine after eating asparagus or the froth in the toilet bowl following a high-protein meal. (Fat, on the other hand, is easily stored in our fatty tissues when consumed.)

As far as the supplement nonsense – there is no convincing evidence that muscle growth would be improved by taking protein supplements. (12) Likewise, taking certain amino acid supplements, like arginine and ornithine, to stimulate growth hormone, insulin and/or testosterone secretion in the body is unfounded. (13,14)

Athletes Eat More Food – Not Higher Protein Food
The World Health Organization recommends people consume about 0.5 grams (g) of protein per kilogram (Kg) (2.2 pounds) of body weight. Commonly, dietitians talk about 0.8 g/Kg of protein for the “average” adult (a figure far too high for our actual needs, however). For strength athletes, recommendations are for 1.2 g/Kg and for endurance athletes, 1.4 to 1.5 g/Kg. 15-17 Increases above these levels do not enhance muscle mass or strength gains. (18)

However, it is imperative that you understand the higher protein needs of athletes do not mean athletes need to eat foods (diets) more concentrated in protein – like more meat, poultry, fish, and eggs – or worse yet take concentrated protein supplements. They simply need to eat more food. In practical terms, this increased need for protein is naturally met because exercise stimulates appetite, causing the athlete to eat more food – thus consuming more of all nutrients. Let me provide a simplified example: A 70-Kg (154 pounds) sedentary man burning 2000 calories consumes a diet of potatoes, beans, and broccoli. This combination of foods provides him 56 grams of protein (0.8 g/Kg) per day. He then begins training for the Boston Marathon – by gradually building up to run 3 hours a day, he increases his calorie intake to 4000 calories a day – or twice as much food. He now consumes 112 grams of protein from his meals of potatoes, beans and broccoli. He is now consuming 1.6 g of protein per Kg of body weight – an amount in excess of even the higher scientifically-backed recommendations.

Winners Forget Protein and Seek Carbohydrate
All of the great feats in history have been accomplished by men following near-vegetarian diets from infancy. Grains, fruits, and vegetables made up most of the diet of ancient conquerors of Europe and Asia, including the armies of Alexander the Great (356-323 BC) and Genghis Kahn (1167 – 1227 AD) . Caesar’s legions complained when they had too much meat in their diet and preferred to do their fighting on corn and other grains. (19)
The protein intakes in athletes are always adequate, whereas carbohydrate intakes often fail to meet their needs because of faulty nutritional advice and dietary myths. 15-16 A notable exception in athletic circles is the Tarahumara Indian ultra-marathon runners and triathletes. These people are known worldwide as "the running Indians," because their entire culture is based around this activity, and they have been known to travel between 50 and 80 miles every day at a race-like pace. There are currently about 50,000 Tarahumara living in the Sierra Madre Occidental in northwestern Mexico. (20) Their diet is practically meatless, consisting of 90% corn and pinto beans (chili), and vegetables (like squash). (21)

There is a growing trend, especially among females, for athletes to eat more like these winning ultra-marathon runners – in other words, vegetarian diets. (12)

Mary Uhl, age 38, from Santa Fe, New Mexico is an example of this trend – she has been a follower of the McDougall diet since she began competing. She just took a 2nd place at Ironman Wisconsin on September 7, 2003. (A triathlon – Swim 2.4 miles, bike 112 miles, and run 26.2 miles. ) She writes, “Earlier this year I was 7th at Ironman New Zealand , and last year I was 3rd at Ironman Canada. I'm still McDougalling (it has been about 7 years now) and I think it is a key reason that I can race well and recover quickly from the Ironmans. This diet is perfect for the training I need to do to race at a very high level in triathlon. People often ask me how I can perform so well with the diet and my question back to them is "How can I NOT perform well on this diet?" It keeps me healthier than ever before (my asthma no longer exists). I can't really understand why anyone would think the standard American diet would be better for an athlete...” (Letter from Mary on 9-24-03 )
Ruth Heidrich is a 68-year-old Star McDougaller from Hawaii who wins triathlons all over the world. She changed from a sedentary lifestyle and the American diet more than 20 years ago after discovering invasive breast cancer that had spread to her bones and lung. (Read more about Ruth under “Star McDougallers” on my web site www.drmcdougall.com .) “Since my diagnosis in 1982, I have completed the Ironman 6 times, run 67 marathons, have been declared "One of the Ten Fittest Women in North America" in 1999, and have a Fitness Age of 32 although chronologically I am 68! Last weekend I did a double-header, a 5K race Saturday and a 10K Sunday with first places in my age group in both. These were my 19th and 20th races this year so far with every one of them gold medals. My total of first-place trophies is now up over 900! I should reach 1,000 sometime before I reach 70. My daily training routine consists of an hour run, an hour on the bike, and alternating a mile swim with weight training. I also do 100 crunches a day in addition. I do all this on a vegan, low-fat diet which I've been following now for 21 years.”
Vital Statistics on Ruth:

My Body fat % = 14%;   Ave. 20-yr-old female = 30%
My Resting Heart Rate = 44;   Ave. adult RHR = 72
My Blood Pressure = 90/60;   Common BP = 120/80
My Bone Density = 529 mg/cm2;   Ave. 30-yr-old female = 411 mg/cm2
(Letter from Ruth on 9-25-03). Learn more about Ruth Heidrich at www.RuthHeidrich.com .

Many other vegetarian athletes are listed at this web site: http://veggie.org/veggie/famous.veg.athletes.shtml

Body Builders should be Vegetarians, Too
Andreas Cahling, a former Mr. International bodybuilder (1980) and vegetarian for more than 25 years, used to tell me the difference between him and other bodybuilders was he did not have to diet for 2 weeks before a competition to get the fat off. Pre-contest dieting was the normal routine for bodybuilders “bulking up on protein” in order to remove that extra layer of fat that covered their rippling muscles. The protein in vegetables is every bit as high quality as the protein in meats. Hard work builds hard muscles. Consider the biggest-muscled animals on earth are pure vegetarians (horses, elephants, etc.) – obviously there must be loads of protein in plant foods. Too many people think they can take an easier route and “eat their muscles bigger” – not true.

Some of the best known vegetarian bodybuilders are (most are lacto-ovo-vegetarian):

Bill Pearl (Mr. America, Mr. USA, and four times Mr. Universe)
Andreas Cahling (IFBB Mr. International)
Hercules Steve Reeves (Mr. America, Mr. World and Mr. Universe – and vegetarian at least part of the time during his competitive career)
Jack Lalane (TV personality and bodybuilder)

There is now an organization for vegan bodybuilders using no animal products. Visit: http://groups.yahoo.com/group/veganbodybuilding/
An inspiring story of a lifelong vegetarian, 77-year-old Roy Hilligenn, can be found at: http://www.cbass.com/Hilligenn.htm

Animal Protein Can Stimulate Growth – At a Price
It has long been rumored that the levels of the muscle building hormone, testosterone, are raised with meat-eating. However, recent research comparing people following various diets has found vegans (no animal products) have 8% more testosterone than lacto-ovo-vegetarians, and 13% more than people on the standard Western diet (with meat and dairy). (22) (Fortunately, this extra male hormone is kept safely bound with a protein to prevent over-stimulation of the tissues, including the prostate.)

So, if not testosterone, then what in the meat-eater’s diet could possibly be growth-stimulating? (22-23)

There may be some truth that eating all that protein stimulates muscle growth. (24,25) Protein raises insulin-like growth factor-1 (IGF-1) in the human body, stimulating the growth of muscle and all other tissues. Meat-eaters are found to have 9% higher levels of IGF-1 than vegans. 22 People eating dairy and eggs (lacto-ovo-vegetarians) have 8% higher levels. (22) Unfortunately, IGF-1 also stimulates the growth of cancer of the breast, prostate, lung, and colon by stimulating cell proliferation and inhibiting cell death – two activities you definitely don't want when cancer cells are involved. (26,27) Eating all that meat and those dairy products could make bigger muscles – but, how often do athletes think about the effects on their health? Beauty is more than skin deep – for sure. And ugly goes clear to the bone.

The rippling firm muscles of athletes send a message of good health, but this appearance is deceptive because what lies underneath is a quagmire of disease. All that “muscle building” food is also loaded with acid, cholesterol, saturated fat, and is deficient in dietary fiber and complex carbohydrate. Looking beyond the exterior you will find bones depleted of strength and structure (osteoporosis) by the acid, arteries filled with festering sores (atherosclerosis) from the fat and cholesterol, and bleeding-bulging hemorrhoids caused by straining to pass a fiber deficient stool (constipation). You may think you are looking at a new Lexus, but rather it’s an overdriven Edsel.

Big is Not Better
Greater height and sometimes greater muscle weight are generally considered desirable qualities and size may be the winning difference for athletes, especially for basketball and football players. However, when winning at life and health, increased body size is counterproductive. Shorter, smaller bodies have lower death rates, longer average life-spans, and fewer diet-related chronic diseases. Research shows shorter, lighter people live longer. For example, men of 5 feet 9 inches (175.3 cm) or less live almost five years longer than men over this height. Men shorter than 5 feet 7 inches (170.2 cm) live seven and a half years longer than men taller than 6 feet (182.9 cm). (28,29) Taller women have more cancer of the ovary (30,31) and breast, (32) and men have more prostate cancer. (33) Overnutrition, especially during youth, results in greater height, and poorer health. (34)

You Can Have Height, Strength, and Life
If you met my 3 children you would find a serious contradiction with the above discussion. My daughter, Heather, is an inch taller than Mary. My oldest son, Patrick, is 3 inches taller than I am, and my youngest son, Craig, is 2 inches taller (and the boys are very muscular, too). They were all raised on the McDougall diet. So how did they grow so tall and strong?

Feeding a high-fat, high-protein diet is only one way for a person to attain greater body size. The alternative, healthy way is to encourage natural development by allowing the growth plates of a child’s long bones to remain open longer, into their mid and late teens. The growth plates (called epiphyseal end plates) are located at the ends of the long bones and, as the name implies, this is where growth occurs. A rise in sex hormones (primarily estrogen) after puberty causes the growth plates to close. (35,36) The rich Western diet prematurely raises sex hormones, causing precocious puberty, and prematurely closes the adolescent’s growth plates. (36) (For more information on precocious puberty and diet see the McDougall Program for Women book.) A healthy diet, like the McDougall diet, allows puberty to occur at the correct age (say 14 to 17 years rather than 8 to 12) – thereby growth continues into the late teens. Therefore, you can have it all for your children and grandchildren – tall strong bodies and good health by feeding them plentiful amounts of delicious meals, like oatmeal for breakfast, vegetable soups and sandwiches for lunch, and bean burritos and spaghetti for dinner. (People from some Asian countries, like Japan, and from our own past are small because of a relative deficiency of food (calories) during their adolescent growing years. 34,37 )

Athletes are People, Too
The diet of a horse is essentially grass and grains. To raise a racehorse would you feed your colt meat? – Of course not. You would just feed it more grasses and grains during growth and training. The same applies to people. Basic nutritional needs do not change with an increase in activity. So the same diet recommended for people applies to athletic people, too. To violate this basic truth results not only in horrific health, but also pitiful performance.

However, the more important lesson we have learned here is: the best diet for athletes is also the best diet for all of us. If a diet very high in carbohydrates – starches, vegetables, and fruits – makes athletes – those living at the extremes of human performance – winners, then following their example will result in superior nutrition for all of us and our families. Can’t possibly be any other way.

References:
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