Ch.11 Weight and Body Composition

What sports are size dependent?

A few sports are size dependent, such as sumo wrestling and ski jumping

Underwater weighing was used to establish some of the early estimations of body fat from cadavers and has therefore long been considered the gold standard of body composition methods

It has also been used as the criterion for the establishment of other methods such as the skinfold technique. Underwater weighing is no longer considered the gold standard because more sophisticated methods are now used (for example, using multiple methods to determine the four-compartment model) as criterion methods, although there is still a lack of data from these newer methods to establish population norms

Body Composition

The measurement of body composition provides the athlete with information about body fatness.

Essential Fat

The minimum amount of body fat necessary for proper physiological functioning; estimated to be approximately 3 percent of body weight for males and 12 percent for females - Of the 12 percent, approximately 9 percent is considered sex-specific fat, the fat necessary for proper hormonal and reproductive functions.

Before taking any supplement, athletes should ask five critical questions:

(1) Is it legal? (2) Is it ethical? (3) Is it pure? (4) Is it safe? (5) Is it effective?

The National Federation of State High School Associations instituted rule changes beginning with the 2006- 2007 season that included...

(1) a body fat assessment no lower than 7 percent in males and 12 percent in females (2) a monitored weight-loss program that does not exceed 1.5 percent loss of body weight per week (7 days) (3) a specific gravity of urine not to exceed 1.025 (a measure of hydration status)

Many athletes today are physically taller and heavier than their counterparts of the past.

- A 2016 study of nearly 18,000 male professional baseball players in the United States over 145 years (1871-2015) lends a cautionary note to the issue of "size." - By comparing the height and weight of each player at the time of their debut (and accounting for age), the authors found, not surprisingly, that both height and weight had increased over time. - However, in the past decade (2005-2015), only 20 percent were normal weight, whereas 70 percent were overweight, and 10 percent were obese. This raises a red flag because most people, including many former athletes, gain body fat as they age

Hydrodensitometry or Underwater Weighing result interpretations

- A person who has more body fat will float more readily (that is, will have a greater buoyant force) and will therefore have a larger volume and a lower density. - Conversely, a person of the same weight with less body fat and more muscle will tend to sink more readily (that is, will have less buoyant force), exhibiting a smaller body volume and higher density. Higher body density is associated with lower body fat.

Interior linemen in American football typically have requirements for greater body mass, even if some of that mass is fat.

- Along with muscle, the additional body mass prevents them from being "pushed around" as easily.

Increasing Muscle Mass while Decreasing Body Fat Is Difficult

- Although this sounds as if it would be easy for the body to accomplish, anabolism (synthesis) and catabolism (breakdown) are biologically opposite processes, and it is difficult to estimate an appropriate daily caloric intake to achieve both simultaneously. - A prudent recommendation is to focus on one goal at a time. - For many athletes, there is a greater benefit to increasing muscle mass than to decreasing body fat. Weight may eventually be the same, but it will probably fluctuate as muscle mass is increased, and then body fat is decreased.

In sports or positions in which explosive power is a requirement or provides a competitive advantage, having a large amount of muscle mass and a high power-to-weight ratio is important.

- Athletes such as male gymnasts; ice hockey players; short distance runners (for example, 100 m runners); speed skaters; high, long, and triple jumpers; and American football linebackers, defensive backs, and running backs are often very muscular and lean and have a high power-to-weight ratio. - Excess body fat may diminish this power-to-weight ratio and is therefore undesirable.

Excessive body fat comprises "dead weight" for the athlete—weight that must be carried but does not contribute in a positive way to the activity.

- Carrying excess weight makes the athlete less energy efficient, so he or she must exert more effort to transport the weight. - This does not mean that performance will always be improved if these athletes attain an absolute minimum weight, however. There is a point of diminishing returns, both for performance and for health, that the athlete must consider

Conjugated Linoleic Acid (CLA) Is Marketed to Athletes as a Way to Change Body Composition and Improve Performance

- Conjugated linoleic acid (CLA) is an isomer of linoleic acid, an essential fatty acid found in lamb, beef, and dairy products. - The major naturally occurring isomer is cis-9, trans-11, but most supplements have a mixture of the natural isomer and a trans-10, cis-12 isomer.

Individuals may be divided into one of three categories based on somatotype or body build: ectomorph, mesomorph, and endomorph.

- Ectomorphs are typically described as being slightly built with less-developed muscle mass and fat stores - Many ectomorphs have difficulty gaining weight. - Mesomorphs, especially males, can gain muscle mass relatively easily and typically do not have excessive amounts of body fat - Endomorphs are characterized as being stocky, with wide hips and a tendency to easily gain body fat, especially visceral fat *Somatotypes may be useful when discussing genetic predisposition and body composition, especially with those who have set unrealistic goals and are struggling with body image problems.

In animal studies, it is the trans-10, cis-12 isomer that can reduce the deposition of fat in adipose tissue; however, this isomer is also associated with deposition of fat in the liver and spleen and insulin resistance in test animal

- In humans, trans-10, cis-12 isomer is likely to be incorporated into adipose tissue, whereas the cis-9, trans-11 isomer tends to be incorporated into skeletal muscle cells - Studies in animals that received CLA supplements for the purpose of weight loss and changing body composition were promising, but results of human studies are inconsistent, in part, because of the differences in isomers used - At the present time, the safety of CLA supplements has not been established in humans, but doses of 3 to 6 g daily appear to be safe

Dehydroepiandrosterone (DHEA) is also a precursor to testosterone and estrogen, but it is considered a weak androgen (steroid) and is not included under the Anabolic Steroid Control Act.

- It has a more general effect on tissues than anabolic steroids or androstenedione. - DHEA diminishes substantially after early adulthood, probably because of a decrease in the number of cells that produce it - Thus, supplements are often advertised as being "a fountain of youth." There is no scientific evidence that DHEA has an anabolic effect or can enhance performance in athletes - Because the long-term safety is currently unknown and effectiveness related to athletic performance is unproven, DHEA supplements for athletes are not recommended

Males and females may store fat in different sites, displaying a gender-specific physiological preference for the pattern and location of fat storage

- Male fat distribution is described as android and is characterized by fat storage predominantly in the abdominal area - Normal-weight females generally store fat in the hips, thighs, and buttocks, a pattern known as gynoid fat distribution

Topic of fat reduction among athletes

- Most trained athletes do not need to lose large amounts of body fat. However, small increases or decreases in body fat have the potential to affect performance and appearance, so fat loss is also a hot topic among athletes. - Some athletes can gain substantial amounts of body fat in the off-season and want to reduce fat stores rapidly prior to the return to training camp.

The magnitude of the desired fat loss or lean body mass gain is a factor in deciding the best time in the training cycle to make body composition changes.

- Small losses of body fat and weight may be a consequence of the athlete's return to pre-season training from the relatively sedentary off-season period. - If the athlete continues to consume approximately the same amount of energy (kcal), then the increase in energy expenditure from a return to training will result in a loss of body fat

BMI is a screening tool for the general population that helps individuals determine a "healthy weight" range What are some assumptions/ limitations made with BMI?

- The BMI formula assumes that adult height is stable and that any increase in scale weight is a result of an increase in body fat. - The use of BMI as a tool to screen for chronic disease risk in the general population

What things should you worry about in terms of changing body composition?

- The establishment of safe minimum body weight is important and must take into account the athlete's current amount of muscle mass, frame size, genetic predisposition to leanness or fatness, and biologically comfortable weight range. - Individual characteristics such as genetic predisposition to fatness or leanness must be considered so that realistic goals can be set. - Trying to obtain an unrealistic percentage of body fat that has been arbitrarily chosen, such as a male who wants to have 4 percent body fat, can be unproductive, ineffective, and dangerous.

Weight Certification

- Weight categories are necessary in certain sports, but the certification of weight puts an emphasis on attaining a certain scale weight in order to compete. - Boxing, wrestling, some of the martial arts such as judo and tae kwon do, and lightweight rowing are examples of sports that certify weight.

Although the use of weight for comparison to others or for tracking individual change over time might be useful, the major problem with the use of body weight is that it gives no information about body composition.

- Weight is also an imprecise measure of health - In most cases, it is more important to know the absolute amount of certain tissues and their relative proportion to other tissues in the body than to focus on body weight.

However, BMI is an important clinical assessment tool with some athletes.

A BMI less than 18.5 may be an indicator of malnutrition, potential menstrual dysfunction, or disordered eating. Such conditions need medical intervention.

In the face of a moderate caloric deficit, an athlete who is performing aerobic exercise will generally maintain fat-free mass or may experience only small declines.

An athlete who incorporates strength training into his or her training program while experiencing a mild caloric deficit may experience increases in muscle mass, and therefore fat-free mass, while losing a small amount of body fat at the same time

Some additional dietary protein is also needed to support the growth of muscle tissue.

Approximately 22 percent of muscle is protein, so it is estimated that increasing muscle tissue by 1 pound would require the incorporation of approximately 100 g of protein 454g x 0.22 = 100 g - These figures are by no means exact, but they do give athletes some guidelines for the additional energy and protein needed to support an increase in muscle tissue

Mass (weight) is easily measured on a scale, but what about volume?

Archimedes' principle is used by two techniques to determine body volume and density.

There is a disturbing trend among youth American football linemen to increase size by increasing fatness

At an early age, a large child who has excess body fat may have a physical advantage because of size. - However, much of this early advantage fades over time, and overfatness in child and high school athletes is often a disadvantage because it negatively affects fitness, speed, self-image, and health - It may also predispose the child to overfatness as an adult and result in increased risk for obesity-related diseases, such as metabolic syndrome

What if the athlete wants to maintain their body composition all through the year?

Athletes can maintain a relatively stable body composition and weight by adjusting their energy intake to meet the energy expenditure requirements of each training cycle.

Restricting caloric intake restricts nutrient intake, and the athlete who wants to lose body fat needs to be cautious of restricting nutrient intake to too great a degree

Athletes who restrict energy intake should increase protein intake to at least 1.8 g/kg of body weight to protect against large losses of lean body mass

For most people, reducing body fat is a relatively slow process, but the loss of body weight can be rapid when achieved primarily by water loss.

Athletes who want to reduce body weight rapidly to "make weight" often use a combination of methods, including excessive sweating and/or diuretic use in addition to fasting and increasing exercise. These techniques can adversely affect training, competition, and recovery, as well as result in mild to serious or fatal medical complications.

How is body density determined?

Body density can be calculated as the ratio of body mass (weight) to body volume. - Mass can be determined easily by measuring the person's weight, and density can be calculated if the body's volume is known

Citrus Aurantium (Bitter Orange) May Be Used in Supplements Advertised as Ephedra-Free Bitter orange is marketed as a weight-loss aid that enhances fat metabolism

Citrus aurantium, also known as bitter orange, contains synephrine and octopamine, which are chemically similar to epinephrine and norepinephrine, respectively. - Although citrus aurantium and similar stimulants can slightly increase RMR, the temporary and small increase in RMR is unlikely to result in clinically significant weight loss - There is little evidence for bitter orange's effect on enhancing fat metabolism, and there are many questions about safety and efficacy - Under both resting and exercise conditions, bitter orange and similar compounds increase blood pressure and plasma glucose. Some minor adverse events, such as a temporary elevation in heart rate, and serious adverse events such as stroke, have been reported

However, gender alone cannot explain fat distribution patterns. Why do all females not have the pear shape and why don't all men have the apple shape?

Females do not always exhibit the typical gynoid pattern because of genetics, menopausal status, and obesity, which may result in a tendency to store excess fat in the abdominal area. Males also differ from one another because of differences in fat distribution within the abdominal region. In some males, excess fat is more readily stored in deep abdominal fat, known as visceral fat, than in subcutaneous abdominal fat.

Most sports involve varying degrees of power and endurance.

For example, basketball, ice hockey, lacrosse, soccer, and tennis players require explosive power as well as endurance. In addition, speed is a critical aspect of their performance. These players need to find a weight and body composition that reflects the proper balance between the amount of skeletal muscle mass needed for power and the amount of body fat associated with speed and endurance.

When compared to male athletes in similar sports, females typically have a higher percentage of body fat than their male counterparts.

For example, both male and female bodybuilders are extremely lean; however, the leanest elite female bodybuilders will have a greater percentage of body fat than the leanest elite male bodybuilders simply because of the differences in gender.

In contact sports, being physically well matched to one's opponent is important, although physical size alone is not the determining factor in most sports.

However, there is a physical uniformity, especially in the position played in contact sports, that dictates the athlete be a certain size, weight, or body composition.

Severe reduction in food intake, such as fasting or a very-low-calorie diet, is not recommended because it interferes with the athlete's ability to train.

In fact, the athlete who wants to lose relatively large amounts of body fat should begin the process after the competitive season ends and, if necessary, continue the weight-loss plan through the early part of the pre-season. Trying to lose large amounts of body fat during the latter part of the pre-season when training volume is high or during the precompetition and competition periods can be detrimental to training, recovery, and performance because energy intake must be reduced at a time when energy and carbohydrate needs are high.

Wrestling is an example of a weight-certification sport that has moved beyond body weight as a singular measure.

In high school and collegiate wrestling, body composition and hydration status are used along with scale weight at the beginning of the season to determine the appropriate weight categories in which athletes may be certified. - An athlete's weight category may be modified during the season to accommodate growth. The use of weight, body composition, and hydration status has greatly reduced the use of dehydration to "make weight."

Many athletes need to increase body size as they step up to the next level of competition (for example, high school to college, college to professional).

In many cases, this means an increase in skeletal muscle mass and body weight. It may also mean a small increase in body fat.

What is the recommended way athletes can take to reduce body fat?

Increase caloric expenditure through exercise - the stimulus of exercise helps maintain fatfree mass while body weight and body fat decline. - Manipulations of frequency, intensity, and duration of exercise, particularly aerobic-type exercise, can substantially increase caloric expenditure.

In general, it is recommended that well-trained athletes lose no more than 1 to 2 lb (0.5 to 1 kg) of weight per week.

Limited research in elite athletes suggests that a slow reduction in body weight of about 0.7 percent, achieved through mild calorie restriction as well as resistance training, may help to protect against the loss of lean body mass and support performance

Many athletes are influenced by the weight, body composition, and appearance of elite athletes in their sport, and there is often uniformity in body composition among elite athletes within certain sports and positions played.

Long distance runners and cyclists, baseball catchers, basketball centers, American football linemen, gymnasts, figure skaters, bodybuilders, rhythmic gymnasts, and powerlifters tend to have more uniformity within their sports than do tennis players, golfers, divers, baseball pitchers, or recreational triathletes.

Daily energy requirement for females and athletes...

Low to moderate-intensity exercise 3 to 5 days/week or low-intensity and short-duration training daily: approximately 35 and 38 kcal/kg, respectively, when activity is equivalent High intensity: baseline energy requirement may be as high as approximately 38 to 40 kcal/kg for females and 45 kcal/kg for males. Extremely high intensity: Extremely rigorous, high-volume training may require 50 or more kcal/kg for females and 60 or more kcal/kg for males.

Large increases in muscle mass also take time.

Male strength athletes in their 20s, such as American football players or bodybuilders, may increase lean body mass by 20 percent in the first year of a regular, heavy-resistance training program supported by a diet with adequate energy, carbohydrate, and protein intakes - However, after the first year, gains in lean body mass are much smaller, and increases of 1 to 3 percent are more likely in subsequent years. - In other words, untrained athletes can experience large initial gains, but trained athletes are likely to experience small gains

What happens if the athlete wants to lose body fat and gain muscle mass?

Many athletes want to simultaneously increase muscle mass and decrease body fat, and achieving both of these goals takes an individualized plan and some trial and error.

What sports are more accommodating with body size?

Many sports accommodate differences in physical size with weight categories so that a wide range of athletes can participate. Examples include wrestling, boxing, powerlifting, some of the martial arts, and rowing.

Mass vs. weight

Mass describes the amount of matter or material that makes up an object, whereas weight is an expression of the force that is exerted by that object due to gravity. - Because the difference on Earth is minute, the terms mass and weight are used interchangeably in this text.

It is estimated that an additional 5 kcal above baseline energy need is required to support the growth of 1 gram of tissue

One pound of tissue weighs 454 g; thus, a rule-of-thumb estimate is that approximately 2,300 kcal are needed to support the growth of 1 pound of muscle 454g x 5 kcal/g = 2,270 kcal *However, there is little research in this area, so the general recommendation is higher than the estimated minimum value. - At present, to promote the growth of muscle tissue, it is generally recommended that males increase daily caloric intake by 400 to 500 kcal and females by 300 to 400 kcal. - However, individuals vary to a great degree, and recommended daily caloric intake must be individualized and adjusted as necessary.

The other extreme may be represented by a ski jumper. A certain amount of strength is required for controlling the skis and for propelling the body into the air at the end of the ski jump, but low body weight is a great advantage for these athletes to stay in the air longer

Other athletes fall somewhere in between these extremes in terms of body mass, body fat, and skeletal muscle.

Physical Size

Size refers to height, weight, and body build.

Body Composition Can Be Estimated by a Variety of Methods

Some of the factors that must be considered with any method are the accuracy or precision of measurement, practicality, ease of use, time required to obtain the measurement, cost, portability, comfort, effort required by the subject, and training required of the technician

At one extreme, the sumo wrestler represents an athlete who must possess a very large body mass. This large body mass is difficult to push out of the competitive ring because of inertia and lack of momentum.

Strength and speed are important for these athletes, but a very large body mass is critically important—a strong and fast sumo wrestler will have little success if he is outweighed by several hundred pounds by his competitors.

Storage fat is composed of subcutaneous fat and visceral fat. What represent the largest amount of fat in the body?

Subcutaneous fat is located under the skin and is typically the largest amount of fat in the body. Visceral fat surrounds organs and is located well below the skin, for example, in the abdominal area.

Relative Need for Power and Endurance

The "optimal" body composition for an athlete must consider the mass, strength, speed, and power demands of the sport, or the position within the sport.

Bone Mineral Density (BMD)

The amount of bone per unit area. Expressed in grams per cubic centimeter

Percent Body Fat (% BF)

The amount of fat relative to body mass. Expressed as a percentage of body weight

Lean Body Mass (LBM)

Total amount of all physiologically necessary tissue in the body; fat-free mass and essential fat (FFM + essential fat). Often used incorrectly to mean the same as FFM. Often used generically when referring specifically to muscle mass (for example, "strength training results in an increase in LBM"). Expressed in pounds or kilograms.

Body composition

The term body composition refers to all of the components that make up the body. - Because of the difficulties of accurately accounting for all of the fat tissue in the body, measurements of body fat are just estimates. Therefore, they should be interpreted with caution.

Fat-Free Mass (FFM)

The total amount of all tissues in the body exclusive of fat, including muscle, bone, fluids, and organs. Expressed in pounds or kilograms

Because the only true measurement of the amount of fat in the body is by chemical analysis of cadavers, all current approaches to determining body composition estimate or predict body fat from some other measurement.

Therefore, all of these methods are indirect determinations and will have some built-in, or inherent, error. In addition, there is potential for technical error in the assessment method itself. It is extremely important to understand the potential for these errors and how they might affect body composition results and recommendations based on those results.

Bone Mass or Bone Mineral Content (BMC)

Total amount of bone in the body. Expressed in pounds or kilograms.

Fat Mass (FM)

Total amount of fat in the body. Expressed in pounds or kilograms.

Body Mass

Total amount of matter or material of the body; commonly used interchangeably with weight. Expressed in pounds (lb) or kilograms (kg).

Muscle Mass

Total amount of skeletal muscle in the body. Expressed in pounds or kilograms

To increase muscle mass what needs to be done?

To increase muscle mass, an athlete must engage in strength training, consume a sufficient amount of energy (kcal), and be in positive nitrogen balance to support tissue growth.

True or False? Attaining a certain body composition cannot predict success in any sport, however athletes may improve their performance by increasing lean body mass or decreasing body fat.

True - When comparing elite athletes in road cycling, the biggest influences on performance are skill, race experience, and volume of training, not anthropometric measurement

What type of fat is more metabolically active? subcutaneous or visceral?

Visceral fat is more metabolically active than subcutaneous fat and is a factor in some chronic diseases

Weight cycling is defined as repeated bouts of weight loss and weight gain.

Weight cycling is common in sports with weight classes that require an athlete's weight to be certified before competition (for example, wrestling, lightweight rowing, boxing, judo, and tae kwon do).

In the human body, two things are less dense than water and act to help the body float...

air and fat

The Anabolic Steroid Control Act of 2004 defined the term anabolic steroid as....

any drug or hormonal substance chemically and pharmacologically related to testosterone (other than estrogens, progestins, corticosteroids and dehydroepiandrosterone). - The numerous compounds that met this definition are considered controlled substances in the United States, which means that they cannot be sold without a prescription. - Androstenedione is banned by most sports-governing bodies, which consider its use unethical and unsafe.

Sprailium

area of the body directly above the crest of the ilium, the hip bone

Athletes are also interested in the ratio of fat mass to total body mass, which may be expressed...

as percent body fat - The weight of the body is also a factor, particularly in sports with weight categories.

Considering minimum carbohydrate, protein, and fat guidelines, it is generally recommended that...

athletes who want to lose body fat not restrict energy intake to less than 30 kcal/kg daily - Diets containing less than 30 kcal/kg daily typically do not meet daily vitamin and mineral requirements and tend to be extremely low in fat.

What sports prefer a wide variety of body types?

baseball, golf tennis, and recreational triathletes

Sports that vary in weight and percent body fat depending on the position played include...

basketball, ice and field hockey, lacrosse, rugby, and soccer

Anthropemetrics

body measurements such as height, weight, waist circumference, and skinfold thickness

Measuring _______ ___________and ___________ ___________________ can provide information that helps athletes attain their performance, appearance, and health goals.

body weight and body composition

There is an inverse relationship between body fatness and performance in some sports, particularly those in which body weight must be transported, as in...

distance running, other endurance sports, and field sports such as high jump

In the fields of exercise physiology and sports nutrition, body composition is often subdivided into the broad categories of fat mass and fat-free mass.

fat mass: total amount of fat in the body. Expressed in pounds in kilograms fat-free mass: total amount of all tissues in the body exclusive of fat; includes muscle, bone, fluids, organs, and so forth. Expressed in pounds or kilograms

To decrease body fat...

energy expenditure must be greater than energy intake. The off-season or the early pre-season periods, when training volumes are lower than the pre-competition period, are typically the best times for substantial losses of body fat.

To change body composition or weight, the athlete must alter...

energy intake, energy output, or both.

Larger decreases in body fat require a...

moderate reduction in food intake along with an increase in energy expenditure because training alone would not likely create a large enough energy deficit to lose a substantial amount of fat in the pre-season training period. - A moderate reduction in food intake will result in a slow weight loss; therefore, losing considerable amounts of body fat means that weight-loss strategies must be initiated well before the competitive season.

Power-to-weight ratio is defined as...

power (measured in watts) divided by weight (measured in pounds or kilograms)

In acrobatic sports, such as gymnastics and figure skating, a high power-to-weight ratio is desirable.

power-to-weight ratio: expression of the ability to produce force in a short amount of time relative to body mass - In other words, it is beneficial to have a relatively high percentage of skeletal muscle to produce force, but at a minimal bodyweight because excess body fat contributes to total weight but not muscle power.

It is inappropriate to use BMI with...

pregnant females (whose increase in weight is due to more muscle, fat, blood, and fluid, as well as the developing fetus), people who have decreased in height because of osteoporosis, or trained athletes - Trained athletes typically have more skeletal muscle and less body fat than sedentary adults - Studies have shown that BMI is also an invalid method for assessing or monitoring body composition in elite female athletes

skinfold thickness measurements

technique of estimating body composition in which calipers are used to measure the width of skinfolds at multiple body sites - referred to as doubly indirect b/c most commonly used skinfold prediction equations have been derived using body density or body fat determined from underwater weighing, which means this method of estimation is twice removed from the original body density and fat measurement

Submersion in water can be used to determine volume either by...

the amount of water that is displaced (for example, water rising as one slips into the bathtub) or by determining the buoyant force acting on the submerged object.

Of primary importance are the specific components of body tissues—

total body mass (weight), body fat (fat mass), muscle mass, bone mass and density, and fluids.