Source Bodybuilding.com

I started a new workout 3 weeks ago, inspired by Serge Nubret. The first week was extremely hard, didn’t think I could do it. It’s now the 3rd week in and it’s much easier. It’s amazing how the body adapts.

Hockey is almost done, but better weather is around the corner. So lots of cardio options – can’t wait to start roller blading.

Now it’s time to control what I’m eating, and get this boy back in shape.

The shortcut to losing weight? Fast food. Not the kind the clown and the King try to shove down our throats, but rather, edible amphetamines-foods that act like speed for the fat-melting motor known as our metabolism. Eat these foods and you’re guaranteed to burn more calories…just by sitting there and listening to yourself digest.

Only one catch: Like any good buzz, this boost is temporary. “The only way to alter your resting metabolism permanently is to gain or lose weight, or to build extra muscle,” says Janet Walberg-Rankin, Ph.D., a professor of exercise physiology at Virginia Tech. But look at it this way: If you have a few of these supercharged snacks and drinks throughout the day, for enough days, you will lose weight.

And that’s if you’re doing nothing. Imagine if you were to stop listening to your stomach serenading you and actually begin exercising, too? The blubber-busting possibilities are endless. So grab a fork; it’s time to add fuel to the fire.

For awhile, nutrition experts hypothesized that the high cholesterol content of eggs raised blood cholesterol levels, which can increase a person’s risk of heart disease. But this hypothesis was never proven. In fact, several studies have shown that the consumption of eggs is not associated with higher cholesterol levels but is associated with higher nutrient intake.

In 2000, researchers set out to assess the nutritional significance of eggs in the American diet and to estimate the degree of association between egg consumption and cholesterol levels. Their straightforward results were published in the Journal of the American College of Nutrition: Eggs make important nutritional contributions to the American diet and their consumption is not associated with high cholesterol levels. Specifically, the study showed that egg consumers had a higher intake of important nutrients like vitamins B12, A, E, and C than non-egg eaters, and that people who reported eating four or more eggs per week actually had significantly lower average cholesterol levels than those who reported eating zero to one eggs per week.

Here are four more ways eggs can enhance your health:

* Eggs are an excellent source of low-cost, high-quality protein. One large egg provides more than 6 grams of protein, yet contains only 75 calories. And the protein is “complete,” providing all nine of the body’s essential amino acids.

* Eggs are one of the best sources of choline. Found primarily in the egg yolk, one large egg provides 30% of the recommended daily allowance (RDA) of this essential nutrient, which plays an important role in brain health and the reduction of inflammation. Many people are deficient in choline, which is found in trace amounts of many different foods.

* Eggs are a great food for those trying to lose weight. Because of the high amount of quality protein in eggs, they make a very satisfying breakfast, which is especially useful for people trying to lose weight. In one study published in the Journal of the Federation of American Societies for Experimental Biology (2007), subjects following low-fat, calorie-restricted diets were randomly assigned to one of two breakfasts: a bagel or two eggs. After eight weeks, the egg eaters experienced 65% greater weight loss, 83% greater decrease in waist circumference, and a greater improvement in energy levels compared to the bagel-eating group. Also worth mentioning is that changes in plasma cholesterol and triglycerides did not differ significantly between the two groups. Researchers postulated that eating eggs for breakfast enhanced weight loss by increasing satiety, resulting in better adherence to a reduced-calorie diet.

* Eggs protect eyesight. Egg yolks contain a highly absorbable form of vision-protective carotenoids like lutein and zeaxanthin, which help to prevent age-related macular degeneration and cataracts. Studies published in the Journal of Nutrition showed that eggs increased blood levels of these nutrients without increasing cholesterol or triglyceride levels.

So how many eggs should you eat? Just because something is good for you doesn’t always mean that more of it is necessarily better. In a 2007 study published in the journal Medical Science Monitor, no significant difference in cardiovascular diseases (like stroke and heart attack) were observed between people who consumed more than six eggs per week and those who consumed one or fewer eggs per week. So a couple of eggs a day, a few days a week, should be safe and health for most people.

According to Becky Hand, a Licensed and Registered Dietitian for SparkPeople, “One egg daily can easily be a part of a well-balanced, nutritious diet for healthy adults.” An important exception is for diabetics, who experienced an increased risk of coronary artery disease when consuming greater than six eggs per week. If you have a medical condition such as heart disease or diabetes, Hand suggests checking with your physician (or dietitian) regarding egg consumption and dietary restrictions.

“Designer” Eggs: Are They Worth the Money? When you go to stock up on eggs, be prepared for an onslaught of choices. Beyond just white and brown, you’ll see a whole new world of choices in the refrigerator case. Are these “designer” eggs worth the extra money? It depends on the designer.

* Cage Free, Free Range, Pastured, and Pasture Raised: You may feel like you’re doing a good deed by purchasing eggs with one or more of these terms on the package. But in truth, these labels really don’t mean a whole lot, as there are no rules or regulations about using these terms.
* Certified Organic: They hens who lay these eggs are cage-free, have outdoor access, and eat a 100% organic and vegetarian diet that is free of antibiotics and pesticides. Third-party auditors enforce these standards.
* Grade AA, A and B: Eggs in the US are classified according to quality and freshness standards established by the USDA. AA is the most superior in quality, followed by A and B.
* Omega-3 Enhanced eggs: When is an egg not just an egg? When it’s engineered to contain Omega-3s. The hens that lay these eggs eat a diet rich in Omega-3s, which includes algae or flaxseed. The eggs they lay contain higher Omega-3 content but taste like regular eggs. These eggs may help contribute to your intake of essential fatty acids, but they don’t contain enough to make up for a diet that is otherwise low in Omega-3s.

No matter what kind of eggs you choose to eat, be sure to follow proper handling and preparation guidelines to ensure that your eggs are safe to eat. Raw or improperly handled eggs can be a source of disease.

* Avoid raw eggs, and foods made with raw eggs (Caesar dressing, homemade mayonnaise, eggnog, and cookie dough). These foods are safe if a pasteurized egg product is used.
* Check the carton to be sure that the eggs you are buying are clean and free of cracks.
* Store eggs in the coldest part of the refrigerator (not in the door), and use within three to five weeks, or by the expiration date on the carton. Hardboiled eggs should also be stored in the refrigerator and used within one week.
* When cooking with eggs, don’t leave the carton on the counter during prep time. Take out the eggs you will use and return the carton to the refrigerator.
* Wash all surfaces, cooking utensils, and skin with warm, soapy water before and after handling eggs.
* Cook eggs until yolks are firm.
* Cook egg-containing dishes to at least 160 degrees Fahrenheit to destroy any bacteria safely.

Give yourself a break! Poached, scrambled, baked or fried—you can rely on the inexpensive and high-quality protein of eggs as part of a varied, healthy diet. “Do be careful with whom your eggs hang out,” says Hand. “Bacon, sausage, and high-fat cheeses can be troublesome characters!”

Chances are, these are the same rules you lift by right now. And that means your workout is long past due for a 21st-century overhaul. Keep in mind, I’m not suggesting that your current plan doesn’t work. After all, at its most basic level, building muscle is simple: Pick up a heavy weight, put it down, repeat. But improve the details and avoid mistakes, and you’ll build more muscle in less time, with less risk of injury. Put a check next to today’s date—it marks the official expiration of your old workout.

Do 8 to 12 Repetitions
The claim: It’s the optimal repetition range for building muscle.

The origin: In 1954, Ian MacQueen, M.D., an English surgeon and competitive bodybuilder, published a scientific paper in which he recommended a moderately high number of repetitions for muscle growth.

The truth: This approach places the muscles under a medium amount of tension for a medium amount of time, making it both effective for and detrimental to maximum muscle gains.

A quick science lesson: Higher tension—a.k.a. heavier weights—induces the type of muscle growth in which the muscle fibers grow larger, leading to the best gains in strength; longer tension time, on the other hand, boosts muscle size by increasing the energy-producing structures around the fibers, improving muscular endurance. The classic prescription of eight to 12 repetitions strikes a balance between the two. But by using that scheme all the time, you miss out on the greater tension levels that come with heavier weights and fewer repetitions, and the longer tension time achieved with lighter weights and higher repetitions.

The new standard: Vary your repetition range—adjusting the weights accordingly—so that you stimulate every type of muscle growth. Try this method for a month, performing three full-body sessions a week: Do five repetitions per set in your first workout, 10 reps per set in your second workout, and 15 per set in your third workout.
Do 3 Sets of Each Exercise
The claim: This provides the ideal workload for achieving the fastest muscle gains.

The origin: In 1948, a physician named Thomas Delorme reported in the Archives of Physical Medicine that performing three sets of 10 repetitions was as effective at improving leg strength as 10 sets of 10 repetitions.

The truth: There’s nothing wrong with—or magical about—doing three sets. But the number of sets you perform shouldn’t be determined by a 50-year-old default recommendation. Here’s a rule of thumb: The more repetitions of an exercise you do, the fewer sets you should perform, and vice versa. This keeps the total number of reps you do of an exercise nearly equal, no matter how many repetitions make up each set.

The new standard: If you’re doing eight or more reps, keep it to three sets or less. If you’re pounding out less than three reps, you should be doing at least six sets.
Do 3 or 4 Exercises Per Muscle Group
The claim: This ensures that you work all the fibers of the target muscle.

The origin: Arnold, circa 1966.

The truth: You’ll waste a lot of time. Here’s why: Schwarzenegger’s 4-decade-old recommendation is almost always combined with “Do three sets of eight to 12 repetitions.” That means you’ll complete up to 144 repetitions for each muscle group. Trouble is, if you can perform even close to 100 repetitions for any muscle group, you’re not working hard enough.

Think of it this way: The harder you train, the less time you’ll be able to sustain that level of effort. For example, many men can run for an hour if they jog slowly, but you’d be hard-pressed to find anyone who could do high-intensity sprints—without a major decrease in performance—for that period of time. And once performance starts to decline, you’ve achieved all the muscle-building benefits you can for that muscle group.

The new standard: Instead of focusing on the number of different exercises you do, shoot for a total number of repetitions between 25 and 50. That could mean five sets of five repetitions of one exercise (25 repetitions) or one set of 15 repetitions of two or three exercises (30 to 45 repetitions.)
Never Let Your Knees Go Past Your Toes

The claim: Allowing your knees to move too far forward during exercises such as the squat and lunge places dangerous shearing forces on your knee ligaments.

The origin: A 1978 study at Duke University found that keeping the lower leg as vertical as possible during the squat reduced shearing forces on the knee.

The truth: Leaning forward too much is more likely to cause injury. In 2003, University of Memphis researchers confirmed that knee stress was 28 percent higher when the knees were allowed to move past the toes during the squat. But the researchers also found a countereffect: Hip stress increased nearly 1,000 percent when forward movement of the knee was restricted. The reason: The squatters had to lean their torsos farther forward. And that’s a problem, because forces that act on the hip are transferred to the lower back, a more frequent site of injury than the knees.

The new standard: Focus more on your upper body and less on knee position. By trying to keep your torso as upright as possible as you perform squats (and lunges), you’ll reduce the stress on your hips and back. Two tips for staying upright: Before squatting, squeeze your shoulder blades together and hold them that way; and as you squat, try to keep your forearms perpendicular to the floor.
When You Lift Weights, Draw in Your Abs

The claim: You’ll increase the support to your spine, reducing the risk of back injuries.

The origin: In 1999, researchers in Australia found that some men with back pain had a slight delay in activating their transverse abdominis, a deep abdominal muscle that’s part of the musculature that maintains spine stability. As a result, many fitness professionals began instructing their clients to try to pull their belly buttons to their spines—which engages the transverse abdominis—as they performed exercises.

The truth: “The research was accurate, but the interpretation by many researchers and therapists wasn’t,” says Stuart McGill, Ph.D., author of Ultimate Back Fitness and Performance and widely recognized as the world’s top researcher on the spine. That’s because muscles work in teams to stabilize your spine, and the most valuable players change depending on the exercise, says McGill. Read: The transverse abdominis isn’t always the quarterback.

In fact, for any given exercise, your body automatically activates the muscles that are most needed for spine support. So focusing only on your transverse abdominis can overrecruit the wrong muscles and underrecruit the right ones. This not only increases injury risk, but reduces the amount of weight you can lift.

The new standard: If you want to give your back a supporting hand, simply “brace” your abs as if you were about to be punched in the gut, but don’t draw them in. “This activates all three layers of the abdominal wall, improving both stability and performance,” says McGill.

Eating processed meat is also linked to a 19 percent higher risk of Type 2 diabetes, said the study, which appeared in the journal Circulation.

However researchers found no higher risk of heart disease or diabetes among people that ate unprocessed red meat such as from beef, pork, or lamb.

Most healthy eating guidelines already recommended limited meat consumption, but until now “studies have shown mixed results for relationships between meat consumption and cardiovascular diseases and diabetes,” said Renata Micha, the lead author of the study.

“Most prior studies also did not separately consider the health effects of eating unprocessed red versus processed meats,” said Micha, a research fellow in the department of epidemiology at the Harvard School of Public Health (HSPH).

The team reached their conclusions by studying information from 1,600 reports from around the world involving some 1.2 million people.

On average, each 50 gram (1.8 ounce) daily serving of processed meat (about one to two slices of deli meats, or one hot dog) was associated with the higher heart disease and diabetes risk, the researchers said.

Lifestyle factors associated with eating unprocessed red meats and processed meats “were similar, but only processed meats were linked to higher risk,” said report co-author Dariush Mozaffarian, assistant professor in the department of epidemiology at HSPH.

While unprocessed red and processed meats eaten in the United States contained similar average amounts of saturated fat and cholesterol, researches found that processed meats “contained, on average, four times more sodium and 50 percent more nitrate preservatives,” said Micha.

“This suggests that differences in salt and preservatives, rather than fats, might explain the higher risk of heart disease and diabetes seen with processed meats, but not with unprocessed red meats,” she said.

In order to decrease heart attack and diabetes risk, it would be best to avoid processed meats such as bacon, salami, sausages, hot dogs and processed deli meats.

“Based on our findings, eating one serving per week or less would be associated with relatively small risk,” said Micha.

But most men eat animal products. And we really do become what we eat. Our skin, bones, hair, and nails are composed mostly of protein. Plus, animal products fuel the muscle-growing process called protein synthesis. That’s why Rocky chugged eggs before his a.m. runs. Since those days, nutrition scientists have done plenty of research. Read up before you chow down.


You Need More
Think big. Most adults would benefit from eating more than the recommended daily intake of 56 grams, says Donald Layman, Ph.D., a professor emeritus of nutrition at the University of Illinois. The benefit goes beyond muscles, he says: Protein dulls hunger and can help prevent obesity, diabetes, and heart disease.

How much do you need? Step on a scale and be honest with yourself about your workout regimen. According to Mark Tarnopolsky, M.D., Ph.D., who studies exercise and nutrition at McMaster University in Hamilton, Ontario, highly trained athletes thrive on 0.77 gram of daily protein per pound of body weight. That’s 139 grams for a 180-pound man.

Men who work out 5 or more days a week for an hour or longer need 0.55 gram per pound. And men who work out 3 to 5 days a week for 45 minutes to an hour need 0.45 gram per pound. So a 180-pound guy who works out regularly needs about 80 grams of protein a day.

Now, if you’re trying to lose weight, protein is still crucial. The fewer calories you consume, the more calories should come from protein, says Layman. You need to boost your protein intake to between 0.45 and 0.68 gram per pound to preserve calorie-burning muscle mass.

And no, that extra protein won’t wreck your kidneys: “Taking in more than the recommended dose won’t confer more benefit. It won’t hurt you, but you’ll just burn it off as extra energy,” Dr. Tarnopolsky says.

It’s Not All the Same
Many foods, including nuts and beans, can provide a good dose of protein. But the best sources are dairy products, eggs, meat, and fish, Layman says. Animal protein is complete—it contains the right proportions of the essential amino acids your body can’t synthesize on its own.

It’s possible to build complete protein from plant-based foods by combining legumes, nuts, and grains at one meal or over the course of a day. But you’ll need to consume 20 to 25 percent more plant-based protein to reap the benefits that animal-derived sources provide, says Dr. Tarnopolsky. And beans and legumes have carbs that make it harder to lose weight.

So if protein can help keep weight off, is a chicken wing dipped in blue-cheese dressing a diet secret? Not quite: Total calories still count. Scale down your fat and carbohydrate intake to make room for lean protein: eggs, low-fat milk, yogurt, lean meat, and fish.

But remember, if you’re struggling with your weight, fat itself is not the culprit; carbs are the likely problem. Fat will help keep you full, while carbs can put you on a blood-sugar roller coaster that leaves you hungry later.

Timing is Everything
“At any given moment, even at rest, your body is breaking down and building protein,” says Jeffrey Volek, Ph.D., R.D., a nutrition and exercise researcher at the University of Connecticut. Every time you eat at least 30 grams of protein, Layman says, you trigger a burst of protein synthesis that lasts about 3 hours.

But think about it: When do you eat most of your protein? At dinner, right? That means you could be fueling muscle growth for only a few hours a day, and breaking down muscle the rest of the time, Layman says. Instead, you should spread out your protein intake.

Your body can process only so much protein in a single sitting. A recent study from the University of Texas found that consuming 90 grams of protein at one meal provides the same benefit as eating 30 grams. It’s like a gas tank, says study author Douglas Paddon-Jones, Ph.D.: “There’s only so much you can put in to maximize performance; the rest is spillover.”

Eating protein at all three meals—plus snacking two or three times a day on proteins such as cheese, jerky, and milk—will help you eat less overall. People who start the day with a protein-rich breakfast consume 200 fewer calories a day than those who chow down on a carb-heavy breakfast, like a jam-smeared bagel. Ending the day with a steak dinner doesn’t have the same appetite-quenching effect, Layman says.

Workouts Require Fuel
Every guy in the gym knows he should consume some protein after a workout. But how much, and when? “When you work out, your muscles are primed to respond to protein,” Volek says, “and you have a window of opportunity to promote muscle growth.”

Volek recommends splitting your dose of protein, eating half 30 minutes before the workout and the other half 30 minutes after. A total of 10 to 20 grams of protein is ideal, he says. And wrap a piece of bread around that turkey, because carbs can raise insulin; this slows protein breakdown, which speeds muscle growth after your workout. Moreover, you won’t use your stored protein for energy; you’ll rely instead on the carbs to replenish you.

One study, published in the American Journal of Clinical Nutrition, pinpointed 20 grams as the best amount of postworkout protein to maximize muscle growth.

You’re doing this because resistance exercise breaks down muscle. This requires a fresh infusion of amino acids to repair and build it. “If you’re lifting weights and you don’t consume protein, it’s almost counterproductive,” says Volek. Protein also helps build enzymes that allow your body to adapt to endurance sports like running and biking.

Powders are for Everyone
Everyone—not just muscleheads—can benefit from the quick hit of amino acids provided by a protein supplement, bar, or shake. Your best bet is a fast-absorbing, high-quality kind like whey protein powder (derived from milk): “It appears in your bloodstream 15 minutes after you consume it,” Volek says.

Whey protein is also the best source of leucine, an amino acid that behaves more like a hormone in your body: “It’s more than a building block of protein—it actually activates protein synthesis,” Volek says. Whey contains 10 percent leucine while other animal-based proteins have as little as 5 percent.

Casein, another milk protein sold in supplement form, provides a slower-absorbing but more sustained source of amino acids, making it a great choice for a snack before you hit the sack. “Casein should help you maintain a positive protein balance during the night,” says Volek. Building muscle while you sleep?

Thanks to protein, anything’s possible.

In his new book, “Racing Weight: How to Get Lean for Peak Performance,” Matt Fitzgerald, a sports nutritionist, writes about an amazing running experience. He worked out on a special sort of anti-gravity treadmill, the AlterG, which uses a cushion of air to lift the body, allowing you to effectively decrease your body weight as you run.

Mr. Fitzgerald started out on the treadmill by running without the machine’s assistance. Then he ran with it adjusted to lift him just enough so that he was 10 percent lighter.

“I felt as if I had become 10 percent fitter,” he writes. Running at his usual pace was suddenly “utterly effortless,” he notes, adding that “it felt like normal running, only so much better.”

Exercise physiologists agree that if your sport is particularly affected by the tug of gravity — running, cross-country skiing, cycling up hills — you are penalized for excess weight. But that leaves some questions: What is the ideal weight for your sport? And how much difference will it make if you actually achieve it?

There have been few direct tests of the body-weight effect, said Hirofumi Tanaka, an exercise physiologist at the University of Texas at Austin. Most of them were done in the 1970s and involved subjects who were asked to run with weights on their backs or ankles. Sure enough, the heavier the people were, the tests showed, the harder they had to work to run at a given speed.

But the runners’ forms were not affected by the extra weight, Dr. Tanaka said. That means that you would probably run the same way if you were heavier. But it would be a lot harder to run at your usual pace, and you’d end up running more slowly.

How much is less clear. Beth Parker, the director of exercise physiology research at Hartford Hospital in Connecticut, said that, for runners, the general rule is that a 1 percent reduction in weight leads to a 1 percent increase in performance.

So, why not just be as thin as you can be?

The problem is that everyone has a point at which further weight loss actually makes their performance worse, said Dr. Mark Tarnopolsky, a muscle metabolism researcher and physiologist at McMaster University in Ontario. Dr. Tarnopolsky, who is a nationally ranked athlete in winter triathlons, adventure racing and ski orienteering, said that people vary so much that there is no formula to figure out the perfect weight.

When Dr. Tarnopolsky was in graduate school, he saw the delicate balance between losing just enough and too much. He and his friends would experiment, losing or gaining a few pounds and testing their VO2 maxes, a measure of the body’s ability to get oxygen to muscles during exercise. In theory, the less you weigh, the higher your VO2 max should be, relative to body weight.

Dr. Tarnopolsky said that he got his best VO2 max — 86 milliliters of oxygen per kilogram of body weight — when he weighed 156 pounds. “Like everyone else, I said, ‘Maybe if I drop some body fat, it will go higher,’ ” Dr. Tarnopolsky said. So he got his weight down to 152 pounds. But to his surprise, his VO2 max decreased, to 82.

The likely reason, he said, was that he had reached a point where his body began burning its own muscle protein for fuel. He was weaker, and his performance was worse, even though he weighed less.

“You could see on the VO2 machine what your body knew was right,” Dr. Tarnopolsky said. “You’d feel tired, stale, lethargic when you tried to drive your weight down.”

Often the only way to know your best weight is by trial and error.

My running coach, Tom Fleming, a former elite runner who won the New York City Marathon twice, in 1973 and 1975, said that he always tells his competitive athletes “that the perfect weight is the weight you are the day you P.B. in your event,” referring to the time you achieve your personal best — or fastest — finish.

“Your body will tell you” your perfect weight, he said, and when you are there, “you will feel fast, race fast.”

Dathan Ritzenhein, an American who is one of the world’s top runners, used a similar system. Mr. Ritzenhein, who broke the national record last year in a 5,000-meter-race and who, at ninth place, was the top American finisher in the marathon at the Beijing Olympics in 2008, said that it took him about 12 years of trial and error to learn his best racing weight. He discovered it last year, his best racing year ever: 121 or 122 pounds (he is 5 feet 8).

That weight is not a natural one for him, he said. If he were to stop training, he would weight about 127 or 128 pounds, and when he is training but not trying to control his weight, he is about 124 or 125. His goal is to try to be at his perfect racing weight a couple of weeks before a big event, losing about a pound a week in the preceding weeks to get there.

He has learned, he said, that if he tries to lose weight too fast or if he continues to lose weight up until his race day, he does not have the energy he needs for his best performance. And if he tries to lose weight too fast, his training suffers.

“It’s a hard line” between losing just enough at the right rate and losing too much too fast, he said.

Other athletes say that they learned through similar experiments.

Andre Agassi, the tennis star, and his longtime trainer, Gil Reyes, discovered through experience that Mr. Agassi’s best weight was between 178 and 182 pounds (Mr. Agassi is 5 feet 11 1/2.)

“We came up with a number, but we did not seek a number,” Mr. Reyes explained in a recent telephone interview. “It was all about him feeling strong and fit.”

Tennis is different from distance running, Mr. Reyes noted. Athletes like Mr. Agassi never know if they will be playing for one or five hours, and they have to be ready for every possibility.

Before he retired from tennis, Mr. Agassi would sometimes gain weight and then stop eating, trying to shed the pounds fast. Mr. Reyes discouraged this. “I said to him, ‘Why do you feel like you have to stop eating to lose that weight?,’ ” he recalled. “ ‘What if you were to eat 10 to 15 percent more, but train 40 percent more?’ ”

Bicyclists in grueling races like the Tour de France also have the problem of maintaining their strength, but for them a little extra weight can make the difference between winning and performing dismally on days when the race has steep hills or mountains.

“I knew from experience and results that I had an ideal weight — or what I thought was ideal,” said Andy Hampsten, a former Tour de France rider and the only American ever to win the Giro D’Italia, in 1988. “If I set too low of a weight goal, I would be weak and stressed,” he said. “If I weighed 4 or 5 pounds more than ideal, I could see I was slower than my competitors.”

Mr. Hampsten, who is 5 feet 9, said that he aimed for a race weight of about 137 pounds, deliberately reducing his intake in the two months before racing season. In the off season he would let his weight drift up to a more comfortable 145 pounds.

The lesson is that, even if the laws of physics and an experience on an AlterG may seem to prove the benefits of a lower weight, exercise science is nowhere near making good predictions for specific athletes, Dr. Tarnopolsky said.

“I know an individual who is one of the fittest ultra-sport athletes,” he said. “She competes in 100 milers, and her body fat is close to 20 percent.”

Yet, he said, “she is one of the most talented athletes I have ever seen.”

Mr. Reyes said that he and Mr. Agassi learned not to let the scale rule your life. “We had a little bit of a phrase,” he said. “The weight scale to most human beings can be like a Ouija board. It can start messing with your head.”

The trick is not to let it.