Dave Ellis R.D., L.M.N.T., C.S.C.S., Applied Sports Nutrition Specialist, President, Sports Alliance Nutrition, Lincoln, NE

Dave Ellis is an accomplished Sports Dietitian and President of Sports Alliance, which provides consulting services to athletics and the food industry.  Dave has earned a reputation as a pioneer and leader in the field of applied sports nutrition and is celebrating his 25th year of practice athletics in 2006.   As the Director of Performance Nutrition support services at the collegiate level (20 years combined – Nebraska and Wisconsin Universities), Ellis orchestrated the most highly evolved performance nutrition and body composition support service models in the country.  Dave also Chairs the Nutrition, Metabolism & Body Composition Special Interest Group of the National Strength & Conditioning Association (NSCA) and is an advisor to the Professional Baseball Strength & Conditioning Coaches Society (PBSCCS) Advisory Board, USADA and the Taylor Hooton Foundation.


Coaches often try to categorize the amount and composition of an athlete’s body mass based on the event or position they compete. All too often athletes who do not have the stamina or speed to move the way the coach wants find themselves attempting to lose body mass to “lighten the load” or being moved to a slower position where they are asked to add additional body mass. Or in the case of cycling participate in a different event.  In reality, body mass may have had nothing to do with why the athlete was not moving well; it could be due to injury, illness, stress, etc. If there were a way to illustrate to coaches and athletes how much potential to carry body mass each individual has based on their mature skeletal dimensions, it would be easier for coaches to more objectively place athletes in the correct events, positions or weight classes in the first place as opposed to the subjective process of trial and error that currently takes place.

As you can imagine stature (height) is the measure most coaches currently equate to weight carrying capacity and yet we see tremendous variability in net body mass for the same heights. Obviously other segmental and body breadth measures must come into play in more accurately predicting frame size and subsequent potential for gains in fat free mass (FFM). Imagine if a coach could rank the skeletal frame sizes of his or her athletes in a manner that highly correlated to their potential to carry FFM. The coach would be able to rank frame sizes from high to low on a team as a way of determining who has the potential to be the largest (FFM and total body mass) athlete to the smallest at each position or event. Even if an athlete has not yet accrued the FFM through maturation and training, the coach would have the ability to determine what the net potential of the individual’s frames might be. Maybe, more importantly, an objective method would exist that could illustrate a point of diminishing return for continuing to focus on adding mass to a frame that is carrying a high ratio of grams of FFM per cc of frame volume. This is a growing problem in male power sports.

Continued subjectivity by coaches and athletes in estimating potential to carry body mass can result in some very negative outcomes. On a clinical level these outcomes have surfaced with dysmorphic-dissatisfied body images of male athletes as they quite often strive for a body mass that is completely unrealistic and quite often unattainable. Whether self-imposed, societal-induced or coach-stimulated, these unrealistic images of what the composition of body mass should be is a rapidly growing problem in western society. We need a new measuring stick to more realistically put into perspective just what a realistic weight range could be relative to volumetric representation of our skeletal dimensions.

Determining robustness of a frame apart from stature is still a problem that challenges the forensic and anthropological community. Much of the error in accurately predicting weight relative to stature has surrounded the individual geometrical variation of the trunk. Some of the more high-tech solutions to this age-old issue seem to be surfacing in the research associated with three dimensional body modeling techniques used by computer animators and medical imaging (DEXA, MRI & CT). Until these techniques are more common and cost effective to evaluate healthy athletes, a more simplified anthropometric means of assessment seems to be the practical solution. Because athletes are so heavily muscled the use of circumferences are highly variable and typically better suited for predicting total body mass.

The purpose of this article is to introduce the concept of taking into consideration the unique geometric variances of the trunk that based on my experience and data can better correlate and predict what a male athlete’s capacity to carry FFM is in comparison to traditional non-geometric methods (height, wrist circumferences and elbow breadth). Historically, the efforts to predict a functional relationship between weight (total or lean body) and concomitant anthropometric measurements have received great attention due to military, design and health interests. However, as far back as this research goes come comments that illustrate the shortcomings of only using stature in this estimation process. “…Fundamentally weight must be proportional, not to length nor surface, but to cubic mass” (Gray & Walker ’21). And thus efforts began to factor in multiple skeletal dimensions and circumferences to better predict total body mass most of which utilized some measure from the trunk (primarily breadth measurements).

As early as this need for volumetric frame estimation was identified, we read sixty years later: “…Data relating to the quantification of body frame size are scarce. The commonly used frame size standards rely almost totally on self-appraisal. To our knowledge even these self-appraisal frame size standards have never been discussed or subjected to quantification. To adequately define body size, frame size must combine a measurement of stature and width in some mathematical and logical way. Additionally, frame size estimation must be essentially unrelated to body fat and be subject to quantification, statistical manipulation and population norming. The relationship between frame size and body composition has never been documented, although it seems logical to expect that frame size should vary as a function of the lean body mass component.” (Katch & Freedson ’82).

We needed something that was more geometric (three dimensional) when assessing an athlete’s frame, not just height. If you look at what is out there, body mass index, (height squared divided by bodyweight) you get a non-geometric, two-dimensional way of looking at the body and its weight carrying capacities. This is not to say it isn’t a valid way of looking at height in relation to total body weight, it just doesn’t tell the whole story especially when working with muscular populations like athletes. But it’s a three-dimensional world and we need to look at the body in three dimensions (Figure 1) to give us accurate assessments in dealing with athletes.

Weight Carrying Capacity in Three Dimensions

You can think of the body’s structure as being similar to scaffolding on a building. Some scaffolds are designed to carry large amounts of weight; others would collapse under the same amount of weight. The whole idea in athletics is to have the right amount of weight (lean/fat mass) in relation the three dimensional capacity of their frame so that the athletes are able to move at maximal functional capabilities—to score the goal, hit the home run, kill the ball or sprint across the finish line winning the yellow jersey.

In today’s training practices with emphasis on hypertrophy (muscle mass.gunnertechnetwork.comelopment), periodization, special nutritional supplements like creatine, and other advanced training methods, there is created a situation where an athlete may carry too much lean tissue and body weight to be at optimal level of functionality based on his/her sport. In addition, with too much weight come joint, tendon and ligament problems in the later phases of an athlete’s career. In early phases, it may just be a performance issue wherein the athlete is not getting the job done on the field, court, diamond or course.

Recently we have seen problems with athletes carrying too much lean mass in relation to performing in hot weather environments. In a contact sport, lean mass comes in handy when generating force to knock someone over, but there is a cost of keeping this large mass hydrated, cooled and buffered. There is a point of diminishing return in acquiring more lean mass. These include orthopedic concerns, diminished performance movement capabilities, environmental issues, and for endurance athletes, metabolic factors. All these factors are more or less severe depending on the sport.

Key Is In The Trunk

Independent of height, what is going to help us differentiate weight carrying capacity of males and females are variations in the trunk. In other words, how much of an individual’s height is trunk as opposed to legs. For our purposes, the trunk is defined as the area of one’s body from the top of the head down to the end of the tailbone. This is a very big factor and needs to be assessed when considering an athlete’s weight carrying capacity. Pearsal reports: “In particular, the trunk represents a segment with the greatest divergence of reported mass values: for instance, the percentage of body mass assigned to the trunk have ranged from 43.6% to 52.4% for males.” (Pearsall ’94).

The number of anthropometric measures necessary to replicate the human body model used in this industry is well beyond what any coach or practitioner has time to acquire (Yeadon ’90). In Yeardon’s example, the 95 measurements taken comprise 34 lengths, 41 perimeters, 17 widths and three depths and requires between 20-30 minutes of the subject’s time. Current under construction on our web site details on how to size up these male frames in an interactive manner will be available in the near future (Table. 1). Trying to describe how to take these measurements and turn them into geometric solids for upper and lower body segments is best done with animations. It’s the three-dimensional perspective of sizing up an athletes frame that has to be considered. A person with a longer, more robust trunk is going to carry more weight in relation to height than a person with a shorter trunk and longer legs.


Table 1. Geometric Skeletal Measurements


X – Xyphoid Level Chest Depth (XCD)
Y – Biacromial Breadth (Width of Shoulder) (ACB)
Z – Seated Height (HTSIT)

X – Hip Depth (HIPD) of Abdomen at Pelvis in Supracristal plane estimated from Bi-iliac Breadth (BIB) * .5 (Waist)  = HIPD
Y – Bitrochanteric Breadth (Width of Hips) (BTB)
Z – Lower Limb Length (LLL) estimated from Height (HT) – Seated Height (HTSIT) = (LLL)


How the Nature of a Sport Affects Weight Carrying Capacity—Considerations for Baseball/Softball, Volleyball, Cycling and Soccer

By the time athletes reach the professional or Olympic level there is a good chance that they have already figured out what is functional for them with regard to weight carrying capacity. In the case of professionals with whom I frequently work, they tend to carry a little extra body fat but have a good read on their FFM situation. However, some take muscle to extreme. They want to put on more and more FFM to try and be a better athlete where, in reality, they might be better off putting in the time to improve movement or sport-specific skills rather than trying to make their motor bigger. As athletes.gunnertechnetwork.comelop there is a need to continually reprioritize their training. They may have achieved success by accruing FFM and think that by adding a little more they’ll get better. They don’t realize there is a point of diminishing return. By providing professional athletes with information about their weight carrying capacity, they are better equipped to understand there is a ceiling for FFM that impacts their performance potential.

In sports there are different ceilings for FFM. For example, in football the ceiling is very high but there are limiting factors. Football players, while large, still have to have a great deal of mobility, agility and ability to play in a hot environment. Even though there is a 25-second rest between plays there is also an endurance factor that is enhanced while playing the popular no huddle offense. A shot putter’s ceiling is even greater. Here the athlete doesn’t have to worry about agility, environmental factors or endurance. The ultimate lean tissue.gunnertechnetwork.comeloper is a body builder where lean tissue is the only consideration.

There are instances where I’ve been able to convince a coach as to what position on a team is best for a particular player because of the player’s weight carrying capacity. Regardless of an athlete’s speed or agility, the body isn’t going to allow that individual to be a tackle or guard in football if the frame can’t carry the FFM. Without the correct FFM an athlete will never to able to carry the mass necessary to effectively play guard or tackle at a high level.

The required amount of endurance, position played, and the competitive event all have a direct affect on weight carrying capacity considerations. In baseball and softball the position of shortstop requires a great deal of agility and mobility. First base requires less movement skill. Considerations of weight carrying capacity vary based on the two physical requirements of the two positions. A shortstop would carry less of their potential weight carrying capacity than the first baseman. In volleyball, the middle blocker and outside hitters would be similar to the first baseman while the libero would be closer to the shortstop in weight carrying capacity considerations. In soccer, the goal keeper would want to be closer to their maximum weight carrying capacity than a midfielder who has to have a great amount of power endurance capabilities. In cycling, where you have a wide variety of events and endurance requirements, a sprinter would want to reach maximum weight carrying capacity for lean tissue within the lower geometrics solids measurements. For a stage racer who has to manage mountains, every ounce of unnecessary mass becomes excess baggage while climbing. Lance Armstrong is a great example of applying “economy of mass” to achieve optimal results.

Gender Considerations

From the anthropological community come these observations: “…Because of the different proportions of the trunk (specifically, bi-acromial to bi-iliac breadth ratios) in males and females, sex specific equations should be used if possible.” (Hiernaux ’85). At this point I have not formalized calculations by sex and most of my data has been taken in male power sports like football and baseball. Why? The consideration is cultural.

In the male athletic population, the desire to gain lean tissue and add body weight is a desirable goal. For female athletes, however, the cultural situation is different. As they mature, many have a goal to blunt accumulation of sex-specific body fat that differentiates endurance, mobility and power output capabilities compared to their younger years. This population doesn’t put an emphasis on “how much bigger I can be” as opposed to the male population. It’s more of an opposite where body shaping and how one looks are the major considerations. Many female athletes want only to know “how can I keep body fat off.” However, the reality is that they may need to know even more about their weight carrying capacity to have a realistic body image and, hopefully, avoid disordered eating behaviors. They need to know that “I’m this big and will always be big. I have a big frame and you know what, I’m proud of it.” This is a healthier prospective. The situation with female athletes creates a need to collect data on them so we can gain a better perspective. We need to shake up this whole body image thing and understanding and applying weight carrying capacity principles could be the way to do it. The reality is you can alter bone density over time with diet and activity (for better or worse) but, you really can’t alter the geometry of your bone structure in rapid fashion like we can our lean and fat mass.

Practical Considerations

This information of knowing the difference in frames of the athletes is very important for a coach. Knowing this information will help prevent coaches from making unrealistic demands on their athletes to change or conform to a position/event standard that is beyond the athlete’s reach. Knowing that a certain athlete will always be smallest according to his/her frame, while another athlete will always be biggest will make the coaches job easier when choosing in what direction the athletes should be steered with regard to position or event. This knowledge will always impact conditioning priorities in the off-season.

For the most part, coaches won’t have time to do the measuring and calculations that are requirements in implementing a geometric weight carrying capacity program for their athletes. But there are some easy things a coach can do. It’s not beyond the scope of any coach to measure height and seated height. This will provide the coach with important information as to who has more trunk relative to height. Someone with the highest ratio of upper body segment to lower body segment (height minus seated height) will be the person who can carry more weight. Start tracking this information and keep a record of it. To measure seated height, have the athletes sit on the floor, tuck their tailbone against a wall and sit straight and tall. This information will help you make realistic decisions with your athletes.

List of References Cited

Gray, H, Walker, A.M., (1921) Length and Weight, Am. J. Phys. Anthropol., 6: 3, 231-238

Hiernaux J., (1985) A Comparison of the Shoulder-Hip-Width Sexual Dimorphism in Sub-Saharan Africa and Europe, In: Human Sexual Dimorphism. Philadelphia: Taylor and Francis, 191-206

Katch V.L., Freedson P.S., (1982) Body Size and Shape: Derivation of the “HAT” Frame Size Model, Amer. J. Clin. Nut., 36: Oct, 669-675

Katch, V.L., Freedson P.S., (1982) Body Frame Size: Validity of Self-Appraisal, Amer. J. Clin. Nut., 36: Oct, 676-679

Pearsall D.J., Ried, J.G., Ross R., Inertial Properties of the Human Trunk of Males Determined from Magnetic Resonance Imaging, Annals of Biomedical Engineering 22: 692-706

Yeadon M.R. (1990) The Simulation of Aerial Movement-II. A Mathematical Inertia Model of the Human Body, J Biomechanics 23: 1, 67-74

About the Author


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.