Module 4: Anthropometric Measures and Body Composition in Athletes Flashcards
What is body composition?
- The body’s relative amounts of fat and lean body tissue (or fat-free mass-FFM)
- Best way to get an indication of athlete’s health (BMI is a screening tool NOT a diagnostic tool)
What are the components of FFM?
- Muscle
- Bone
- Water
- Organ tissues
What are the components of total body fat?
Total body fat = essential fat + storage fat
What is essential fat?
- Fat required for normal physiological function and insulative protection of major organs
- Consists of fat within:
1. Major organs
2. Muscles
3. Central Nervous System
How much of total body weight is essential fat?
- 3-5% total body weight in males
- 8-12% total body weight in females (need more to support reproduction)
- Some athletes like bodybuilders will have lower ranges
- EDs like anorexia nervosa may have encroachment into essential fat stores
How is body composition broken down by gender?
- Greater amounts of muscle and bone in men, less storage and essential fat in men
- Components relate to how RMR equations are estimated. Correct for unknown differences in body composition based on gender
What is storage fat?
- Nonessential fat stored as adipose tissue near the body’s surfface
- The component people are looking at reducing when they “want to lose weight”
- More storage fat in some sports may provide benefit, need to look at sport athlete is in and what is needed for it
What is Percent Body fat (%BF)?
- Percentage of total body weight represented by fat
- Primary index used to evaluate body composition
- Several methods are available to estimate body fat levels with varying accessibility and accuracy
- Indirect measurements, short of doing an autopsy will never know exact amounts
- Can provide a good way to see how athlete is changing based on recommendations/health
What is fat free mass (FFM)?
- Body mass minus all extractable fat
- FFM = Body Mass - Fat mass (%BF x BM)
How can you measure effectiveness of change?
Repeated body composition measures to show how things have changed rather than just a snapshot
What are the purposes of evaluating body composition?
- To help assess health risks and determine needed behavior changes for optimal health
- To help athletes determine the best body composition for performance in their respective sport
→ No distinct cut offs, anecdotal evidence of top performers but can still have success even if body composition isn’t normative (e.g. Yamamoto)
What are the effects of excessive body fat?
- Can increase risk of chronic disease such as:
- CVD
- Type 2 diabetes
- Hypertension
- Cancer
What are the effects of low levels of body fat?
- Extremely low levels can result in reproductive, circulatory, and immune disorders and are associated with RED-S and malnutrition
What are the common methods for assessing body composition?
- height, weight, BMI
- Waist-to-hip ratio (and body girth measurements)
- Skinfold measurements
- Hydrostatic (underwater) weighing
- Air displacement plethysmography (e.g. BodPod)
- Bioelectrical impedence analysis (BIA)
- Dual-energy X-ray absorptiometry (DXA)
What are the types of assessment models?
- two compartment - FM and FFM
- three compartment - Fat, LM, Bone
- 4 compartment - bone, water, protein, fat
What are the methods of assessing height?
- Best measured using a stadiometer
- Ensure the subject removes shoes, stands straight up with heels together, holds deep breath during measurement
What are the methods of assessing body weight/mass?
- Best measured on a calibrated scale at set time of day
- Ensure the subject removes shoes, wears minimal clothing (if nude weight is not possible)
- BW = pounds
- BM = kg (1kg = 2.2lbs)
- Never weigh in a group and only weigh if it is necessary, have consent, and can tell them they do not have to look
What is Body Mass Index?
- Based on the concept that a person’s weight should be proportional to height
- Used to estimate degree of obesity in large populations
- Does not take into account % of fat or FFM (not very useful measure for athletic populations)
- BMI = BM (kg) / height (m2)
- Population screening tool, not diagnostic!
- Not appropriate for use in populations like pregnancy, elderly population, athletes)
What is waist-to-hip ratio?
- Provides evaluation of body fat distribution
- Waist circumference: should be measured at the narrowest point below the rips
- Hip circumference: should be measured at the widest point (around the gluteus maximus)
- Depends upon skill of tester and being able to hit landmarks
- Can then use girth/circumference to estimate %BF by using equations
What are skinfold measurements? Are they accurate?
- Highly correlated (if done correctly) with other methods of measuring %BF (including DEXA and hydrostatic weighing)
- Multiple sites are measured and %BF is calculated using the sum of the sites (3 site, 4 site, 7 site methods)
- Measurements should be taken on the R side of body
- Accuracy is predicted on the skill and experience of the tester
What is hydrostatic weighing?
- Also known as underwater weighing
- Historically the most commonly used lab technique for measuring %BF
- Uses whole-body density to calculate body comp based on Archimedes’ principle (fat more buoyant than lean tissue)
- Cons: time consuming, not feasible to test large number of athletes, and methodology may not be comfortable
What is air dysplacement plethysmography?
- calculates %BF from body density (similar to hydrostatic weighing)
- Uses computerized air pressure sensors to determine amount of air displaced (rather than water)
- Bod pod device used for this method
- May be claustrophobic, hard to get repeat measures
What is bioelectrical impedence analysis and its cons?
- Rapid, non-invasice, and inexpensive method of measuring body comp
- Sends electrical current through the body to estimate body fat (based on principle that fat is less conductive than lean tissue)
- Cons: possesses a higher degree of measurement error (measurements may be affected by subject’s hydration status)
- More widely available
- Need water for current and will overestimate BF if dehydrated
- Accuracy not as important if only looking at change in numbers
What is dual energy x-ray absorptiometry (DEXA)?
- Uses a series of low-dose, transverse radiation scans, providing high degree of accuracy and regional analysis
- Provides measurements of bone mineral, fat, and nonbone lean tissue (able to measure visceral fat as well)
- Cons: expensive, need equipment, testing staff
- Not as practical for sport, done for a specific purpose or screening
Compare and contrast the different assessment methods. What are the pros and cons of each?
What are the BMI ranges?
What are the waist-to-hip ratio norms?
A trainer believes that all sports should have low body fat? What would you say to them?
- Different body types are seen in different sports and can provide advantages
- Depending on sport there may be a body type and thus body fat associated
- Some athletes naturally have the body type needed and some athletes will have to change. By no means is it a be all end all
What are the fitness categories for %BF for Men and Women of varying ages?
What factors need to be considered when assessing body composition in athletes?
- Needs/goals of the athlete (e.g. an athlete looking to increase lean mass)
- The most appropriate method for your situation, based on:
- the resources (time, cost, etc) and equipment available to you
- Validity, accuracy, and reliability of methods
- Ability to obtain serial/repeated measures
Why are body fat measurements important in terms of nutrition and training?
- Body composition does not directly determine performance, however, it may be relevant to measure depending on the athlete/sport type
- Measurements can be used to help inform appropriate training and nutrition strategies for fat loss and muscle gain
- Training and nutrition have to be married to see composition changes
What are challenges of assessing body composition?
- Method and accessibility
- How to interpret the results
- Deciding whether to make body composition changes and if so what the body composition goal should be
- How to alter body composition with training and nutrition
What are the challenges to changing body composition for athletes?
- Athletes are already active and increasing activity levels/training to create an energy deficit may not be an option
- Limiting energy intake is risky → may not have enough calories to fuel performance
- Eating disorders are common in some sports and the risk of promoting or worsening a an eating disorder must be mitigated
- Athletes are busy and lack time and skills to plan meals, prepare foods, and eat structured meals
- There is variation, by sport, in what is considered an optimal weight
- Should not change body composition in the middle of the season
- Genetic influences
- Expectations may not match what is reasonably possible in terms of time required, magnitude of results, impact on performance
- Futile cycles
What is meant by a futile cycle?
- Fat loss and muscle gain are contradictory provesses from a metabolic perspective
- One requires catabolism and one requires anabolism
- Timing matters and consistency is key
- Cannot build muscle and lose fat at the same time, need to pick one or the other. Build muscle first then work on fat loss afterwards
What should the goal of body composition changes be?
- Setting the goal = defining the end indicator
- The goal should be to alter body composition while maintaining or enhancing optimal performance and promoting and maintaining overall health while decreasing risk of injury
Should we use BMI for athletes?
- BMI is not an ideal tool to use when setting goals for fat loss or muscle gain
- BMI is a simple comparison of weight to height to health risk
- BMI is a good screening tool for the general population
- BMI is insensitive to body composition, particularly where the individual is carrying larger amounts of muscle mass than the BMI formula was validated on
- True measures of body compostion are preferred as tools for goal setting
What are reasonable goals for body composition changes?
- Lean mass gain ~0.5lbs per week
- Fat mass loss 1-2lbs per week
- Fat mass gain (very slowly, nutrient stores/fat soluble vitamins)
When setting the goal of body composition changes what needs to be considered?
- time available to reach goal
- How much of a change in mass per week
- TIME body composition change is always best addressed in the offseason
What happens when we restrict calorie intake? What happens when we return to habitual caloric intake?
- When we restrict calorie intake we lose muscle mass and fat mass in equal amounts
- When we return to habitual caloric intake we gain more fat mass and gain some muscle mass
- Ideally we want to limit both the amount of muscle mass that is lost and the amount of fat mass that is regained (losing muscle mass = lose RMR, slower if you regain that weight again)
During energy restriction, rates of ___________ are suppressed
MPS
- Energy deficiency impars restistance training gains in lean mass but not strength
- Even when training, if you are at energy restriction will not have gains
What impact on muscle mass and MPS does hypocaloric eating have?
- Negative energy balance (hypocaloric eating) results in muscle mass loss, the extent of which parallels the degree and duration of the energy deficit that is incurred
→ > energy deficit > observed loss of muscle mass over time
→ Protein being used as an energy source/substrate - Under energy-restricted conditions, a greater proportion of amino acids are catabolized for energy production, resulting in fewer amino acids available for muscle anabolism and muscle loss
What is the protein intake recommended to maximize hypertrophic potential of SM following a resistance-training intervention?
1.6g/kg/day
How can one mitigate MPS decline during periods of energy restriction?
- Protein intakes of ~2.3-3.1 g/kg/day when paired with resistance exercise, may help to preserve muscle mass during periods of energy restriction
- Leaner individuals with resistance training experience who are more vunerable to losing lean body mass during energy restriction should aim for a higher end of this range
Why is mitigating MPS decline during energy restriction hard?
- Have to eat crazy amount of protein!
- Cost
- Need to structure/plan eating to hit protein intake targets
- Need to rely on supplemental/concentrated sources of protein
What are the main drivers of MPS? How does this relay back to energy deficit?
- Resistance exercise and weight training
- Increased protein intake
- When an energy deficit is present, increase both resistance exercise and protein intake to help attenuate muscle mass loss!
What are the nutrition and exercise recommendations when trying to gain lean mass?
- Calorie surplus (250-500kcal or 10-20% above intake)
- 1.6g/kg/day protein
- Carbs focus of remaining surplus, fat stay at 20-35%
- progressive resistance training aimed at volume to promote hypertrophy
- HIIT rather than slow, steady aerobic training (long intense may inhibit MPS)
What are the nutrition and exercise recommendations when losing weight?
- Moderate calorie deficit of same magnitude with gaining mucle
- 2.3-3.1g/kg/day of protein and presleep bolus
- Enough carbs for performance but reduction in carbs and fat from baseline
- Resistance training to limit atrophy
- Slow steady aerobic training with a mix of HIIT
What are the recommendations if you want to gain/restore fat mass to healthy levels?
- Make sure they are in a calorie balance for optimal energy availability (>40kcal/kg FFM/d for males and 45 for females for optimal; <30kcal for low energy availability)
- 1.2-2.0g/kg protein
- 6-12g/kg carbs (depending on activity level) and 20-35% fat
- Exercise may decrease to promote optimal EA. If unable to limit energy expenditure from training, eliminate extra sessions
If an athlete told you they wanted to lose fat in just there arms what would you say?
- Trying to promote selective fat reduction in specific areas of the body does NOT work
- Negative energy balance stimulates fatty acid mobilization through hormones and enzyme action that targets depots throughout the body
What are some practical tips for fat loss?
- Adopt a low-energy dense diet
- Appropriately time meals and snacks
- Limit energy-containing beverages
- Set realistic fat/weight loss plans and goals
What does “adopt a low energy dense diet” mean?
- Energy density = amount energy (kcal)/amount (g) of a food
- Low energy dense foods are typically higher in fibre and water and lower in fat → promotes fullness
- A 10% decrease in dietary energy density will result in a 10% decrease in energy intake
- Reduces the reliance on portion control and counting calories
- Nutrient rich
Classify foods by energy density
What is the foal of appropriately timed meals and snacks?
- Goal: limit feelings of huner and risk of hypoglycemia
- Athletes should aim to eat something roughly every 2 to 3 hours during the waking part of their day
- Approximately 3 meals and 3 snacks
- Consider the timing of training sessions and games
Why should one limit energy-containing beverages and what does this entail?
- Energy containing beverages can add significant calories to an athlete’s day while providing very little nutrition
- May also interfere with perceptions of hunger
- Limit: soft drinks (pop, fruit drinks/punches), coffee and tea drinks, energy drinks, fluid replacement beverages outside of sport
- Low hanging fruit!
What goals are realistic for body composition changes?
- Time fat loss activities to the off season → restricting energy intake during an athlete’s competitive season can have disastrous results
- Identify a realistic body composition goal → Body comp versus body weight goal
- One to two pounds per week or losses of ~0.7% body weight/week (on average) is a realistic goal for fat loss that limits loss of LBM
Why may an athlete be struggling to lose body fat?
- Haphazard or inconsistent eating patterns (likely main culprit)
- Filling up on high calorie/energy dense foods or liquids
- Failing to plan ahead
- Under-estimating their intake of foods or the portions they are eating (especially high calorie foods)
- Genetics
What are some practical tips for muscle gain in athletes?
Muscle gain requires coordinated:
- Dietary changes
→ additional calories
→ frequent eating
→ Protein rich food choices (especially leucine containing foods)
- Training
→ Periodized strength and conditioning
- Rest/recovery (sleep is critical)
- Realistic plans and goals are critical!
What is the importance of consistency and timelines for muscle gain?
- Muscle gain takes time, patience, and consistency! Athletes need to allow time for the body to develop new cells and tissues
- Timing matters! When significant changes in body composition are made, it is favourable to make changes in the off/pre-season since the demands of competition and travel will make consistent body composition changes more difficult to achieve
What are the dietary strategies for muscle gain?
- Increase daily calorie intake by 500 to 1000 additional calories/day
→ In order to create new muscle tissues by adding in 1-2 snacks or increasing portion size at meal times
→ Additional calories should come from all nutrients, not just protein - Additional calories should come from:
→ Real foods (versus supplements) most of the time
→ Nutrient dense foods - Increase protein and leucine intake
- Ensure foods containing the AA leucine (meat, fish, poultry, milk and milk alternatives and legumes) are spread evenly throughout the day
→ At all meal and snacks, not all at one time, to aid in the growth of new tissue
→ Eat a bed time snack to fuel recovery that occurs during sleep - include a source of protein (cereal + milk, smoothie, cheese + crackers)
What is the importance of dietary planning for muscle gain?
- Athletes are unlikely to eat the volumes of food and amounts of protein needed for muscle mass gain if meals and snacks are not pre-planned
- Plan ahead - outline meals and snacks for the week. Shop at least once per week to have extra calories readily available
- The athlete has to be prepared to carry foods with them to support consistent intakes of total calories and protein across the day
Why might an athlete be struggling to gain muscle mass?
- Haphazatd or inconsistent eating patterns (most common)
- Filling up on low energy dense foods or liquids
- Failing to plan ahead
- Under-estimating the volume of food required to achieve calorie targets
- Genetics
- Unrealistic goals → timing, potential
Is losing weight easy?
Substantial weight loss is possible across a range of approaches to decreasing energy intake relative to EE. HOWEVER, long-term maintenance of weight lost through dieting/energy intake restriction is much more challenging
Why is weight regain regardless of weight loss strategy used typical?
- The obesogenic environment
- Physiological responses to weight loss
- Learned behaviors
What does it mean by “we are living in an obesogenic environment”
- Environment we live in today makes gaining weight easier through:
- Easily accessible high fat, sugar, and high calorie foods
- Sedentary behavior is increasd, NEAT on average has decreased significantly due to technology
- People will struggle with weight just by virtue of our environment (e.g. drive thrus)
What are the physiological responses to weight loss?
- Naturally geared towards weight regain through increased energy intake and decreased energy expenditure
- Loss of weight via muscle loss causes REE to decrease and decreased activity leads to less NREE
- Homeostatic mechanisms to keep us in balance (orexigenic vs anorexigenic) but we are largely influenced by environment, hedonic reward systems, and behavior
What can occur after weight loss?
- Increased hunger and decreased satiety, satiation via increased ghrelin and a reduction in other hormones
- Decreased energy expenditure by decreased TDEE, TEF, RMR, PAEE
What can learned behaviors do and give examples of them
- Learned behaviors related to food selection (type and amount) and physical activity draw people back following a substantial weight loss if there is no long-term maintenance strategy or supports
- Cooking habits are decreasing, rely on food service (not selling foods people need but selling foods people want)
- Dining out (greater portion size)
- Sleep deprivation (increase carb intake to moderate fatigue)
- Sedentary behaviors
- Patterns of association/socialization (eating at events)
- Culture
- Food as psychological coping mechanism
How can weight loss be maintained?
- People need support
- Weight management programs with a focus on lost weight demonstrate improved long-term weight loss compared to programs without maintenance visits
Why are athletes susceptible to fad diets?
- Some athletes are conscious of their weight which makes them want to try fad diets or listen to quick fixes
- Confused about what works and have unrealistic goals
Define fad diets
- A fad diet is a plan that promotes results such as rapid and/or significant weight loss without robust scientific evidence to support its claims
- Popular fad diets include plans that are very restrictive (E.g. low energy, low volume, or both) or an unusual/”magical” combinations of foods
- They may promote eating certain foods at certain times of the day
- Fad diets often consist of expensive and unnecessary food products, ingredients and/or supplements
What are the characteristics of fad diets?
- Promise a magic bullet to lose weight without having to change your lifestyle in any way. These include diet pills, lotions, wearables such as sweat suits
- Promise rapid weight loss of more than 1kg (2lbs) of body fat a week
- Suggest that there are magical fat burning effects of foods such as the grapefruit diet or hidden ingredients in foods (e.g. caffeine/coffee alleged fat burning substances such as green tea extract or raspberry ketones)
- Promot the avoidance or restriction of a whole group of nutritious foods
- Substitute foods with supplements, expensive ingredients, special products
- Promote eating mainly one type of food (mono diet)
- Eating foods in particular combinations based on genetic type or blood group
- Overweight is caused by a food allergy or yeast infection
- Detoxing or avoiding foods
- No evidence other than testimonials
- Appearance based goals
- Identify problem, suggest solution then sell product
- Recs based on single study or misinterpretation of science
- Based on a secret docs don’t want you to know/haven’t discovered
What are the risks of fad diets?
- Produce an initial weight loss that is based on the loss of lean muscle and fluid loss instead of body fat
- Often these diets cannot be followed long term as people become fed up with the rigid rules and limits
- Internal cues around hunger and fullness ignored which can lead to cycles of weight loss followed by weight regain
- Disruption to a person’s psychological relationship with food, leading to feelings of failure rather than the development of skills and confidence to manage diet and weight in a healthy manner (think the failure is a reflection of them and their will power)
- Fad diets promote loss of LBM and can ultimately make achieving a healthy body weight challenging
What is the ketogenic diet?
- Very high fat, moderate protein, low carb eating pattern that are inconsistent from general, healthful eating
- On a KD, CHO from all sources is severely restricted
- Restricts or eliminates many nutrient-rich foods as sources of CHO, including fruits, vegetables, whole grains, milk, and yogurt
What happens when on a KD?
- Has been shown to effectively lead to short-term weight loss, reduction in hyperinsulinemia, and improvement in insulin sensitivity
- Produces an initial weight loss that is based on the loss of LBM, glycogen, and fluid rather than body fat
- Can result in severe hypoglycemia
- Long term compliance with KD is a limiting factor
What is intermittent fasting?
- IF involves alternating between periods of eating and fasting
- This type of eating is often described as “patterns” or “cycles” of fasting
- There are several effective approaches to IF
- Different people may attempt different approaches to IF
What do the results of IF show?
- IF (ADF and 5:2 Diet) is associated with significant beneficial outcomes on BMI, body weight, fat mass, LDL-C, total cholesterol, triglycerides, fasting plasma glucose, fasting insulin, and systolic and diastolic blood pressure in adults with overweight or obesity, BUT…
- Participants frequently experience a plateau when additional weight loss is not further achieved because of the metabolic adaptation of the human body, and
- Decreased adherence IF as a weight loss strategy results in weight gain
- Can promote binge eating!
What are the different types of IF?
What is the paleo diet?
- A paleo diet is an eating pattern that is supposed to mirror the way that humans ate during the Paleolithic (hunter-gatherer) era thousands of years ago
- There is no one version of the paleo diet
- People who follow a paleo diet tend to eat large quantities of meat, fruit, vegetables, nuts, and seeds but restrict legumes, milk products, eggs, and grains
What are the claims about the paleo diet? What does evidence show?
- Purported to improve cholesterol levels, reduce BP, enhance glycemic control, promote weight loss, improve gut health, reduce all-cause mortality
- Evidence to support the Paleo diet is lacking
- One much reported meta analysis found positive associations between Paleo diet and improved health metrics but significant concerns have been raised about the methods and quality of this work
What are you supposed to eat on a paleo diet?
- Expensive!
- Lose weight because there are many food restrictions, limiting availability of food you can choose
What is the national weight control registry?
- Established in 1994 by researchers at the university of colorado
- Largest prospective investigation of long-term successful weight loss maintenance
- The NWCR is tracking over 10,000 individuals who have lost 30lbs or more and kept it off for more than 1 year
- Goal: To examine the behavioral and psychological characteristics of weight maintainers as well as the strategies they use to maintain their weight loss
What are the characteristics of people that successfully lose weight?
What is the importance of breakfast?
People that eat breakfast in the mornings have greater improvements in weight and waist circumference. May help curb hunger and overeating later in the day
How do fad diets connect to athletes? What should be done?
Athletes are concerned about body weight. Athletes like the general public need to be made aware of the limitations of fad diets as well as strategies that are likely to promote sustained fat losses
