Optimizing body composition and weight for peek physical performance is a challenge many active individuals face. Both athletes and active adults fall victim to the promises of quick fix diets or diets touting a specific ratio of carbohydrate, protein and fat. In most cases these diets are more harmful than helpful in optimizing physical performance.
At the completion of this learning unit, you will be able to assess an athlete to determine the appropriateness of weight loss or gain and provide recommendations healthfully attaining these goals in a manner that aids physical performance rather than hinder it.
When working with athletes, weight should be assessed along with body composition and circumference measurements too. Athletes tend to have greater muscle mass and therefore higher body weights compared to standards like the Hamwi equation. Weight loss that results in muscle loss is likely to negatively affect physical performance. You should also assess the other aspects listed to get a full picture before setting goals and recommendations. Drastic cuts in calorie intake for weight loss will hinder performance and energy levels, and large increases in calories for weight gain will likely lead to additional body fat.
It is also important to remind athletes that body composition can be influenced by a number of factors, not just what they eat or how hard they work out. Recommendations should be individualized based on these factors.
If an athlete is on a weight loss plan, lean mass should also be monitored along the way. Loss of lean mass means an undesirable decrease in strength & power and a decrease in resting metabolic rate.
Normal body fat percentages are given. Note the difference from what was previously stated as essential. Getting as low as the essential numbers is not necessary. You will find that some sports seem to lend themselves to a leaner or heavier body type for better performance and competitiveness.
There is often a focus on body fat in athletes because excess is likely to some aspects of the sport. A lean gymnast will likely have an easier time with a giant swing around the high bar than an overweight gymnast.
There are multiple methods for estimating energy needs that can be used that you have learned in other courses. The Cunningham equation however, is one that is often used with athletes because it takes into account fat free mass. To simply determine the resting energy expenditure, multiply the athletes fat free mass in kg, by 22 and add 500. You then must add energy for activity. So to determine the total daily energy expenditure, you need to add resting energy expenditure plus non-training energy expenditure plus physical activity expenditure. Non-training energy expenditure is the energy the athlete expends when they are not training such as working, sitting in class, or preparing meals. Athletes may have very demaning training sessions but then spend the rest of the day in sedentary activities. To determine physical activity expenditure, you will need to use various tables or charts that estimate calories use by the minute for the activity and body weight.
Here is an example of how to use the Cunningham equation. Remember, you must know the body composition to use this calculation.
These are some of the consequences of restricting calories for weight loss purposes. Most are not beneficial to the athlete.
You will find that some athletes lose weight more easily than others and some can gain weight more easily than others. This is likely due to a genetically determined metabolic efficiency. Also, for athletes training at high levels, the thermic effect of activity may be high enough to result in weight loss without intentional restriction of calories.
Athletes may find it challenging to lose weight because they are already exercising a lot and cutting back on calories may mean not getting enough for proper recovery. They may also fatigue more easily.
In instructing an athletes on weight loss, it is important to make only modest changes in calorie intake (≤ 250 calories) to prevent the athlete from becoming too hungry and unable to recover adequately. Aim for only 5-10% weight loss at a time. Start by estimating calorie needs and evaluating current calorie intake and adjust as needed.
Optimize protein and carbohydrate intake for recovery. Decreasing fat intake is the easiest way to eliminate excess calories with little or no impact on physical performance.
It is best to focus on weight loss during the off season rather than during the competitive season. Eating small meals/snacks every 3-4 hours works well with athletes. Using sports drinks during exercise can help keep energy levels up but must be considered in the overall calorie intake. Having a post exercise snack can help prevent feeling sluggish and feeling over hungry at meal times.
Focusing on performance goals is one way to motivate athletes to work toward nutrition goals. Charting weight and body composition can also be a motivator.
Athlete’s in weight class sports often use weight cutting strategies that are not considered safe or healthy.
These of some of the consequences of unhealthy weight loss strategies.
Anorexia nervosa typically includes severe calorie restriction and an intense fear of being fat along with other criteria shown.
Bulimia is characterized by binging and purging cycles. Excessive exercise training can be a form of purging. This is hard to identify in athletes.
Anorexia and bulimia have very specific diagnostic criteria. If someone has some of the characteristics but not all, they may fall into the category of EDNOS. The key here is that the eating behavior has a negative effect on the persons ability to normally function in daily life.
Here are additional signs that an athlete may be struggling with disordered eating behavior.
Although female athletes are at greater risk, males do develop eating disorders as well. Screening tools are available to help you identify athletes who may need referral to other professionals.
As mentioned previously, males also developing eating disorders too. But they be more concerned with bulk instead of thinness.
Here are some things you can do as the RD to help prevent disordered eating behavior and promote a healthy self-image.
In summary, know that athletes do struggle with issues of weight gain and loss. It is best to consider body composition along with weight when setting goals. Keep changes in calorie intake modest. Cutting 500 calories out of an athletes diet will likely leave them hungry and fatigued, start with smaller cuts like 200 calories less for weight loss. Adding too many calories too quickly for weight gain can pack on pounds of fat not muscle. Finally, be aware of signs and symptoms of disordered eating and educate athletes, coaches, and parents on healthy weight and body composition goals to prevent disordered eating practices.
And this concludes the lecture on weight management in athletes.
Weight Management in Athletes Lecture
WEIGHT MANAGEMENT Lona Sandon, M.Ed., R.D., L.D. Assistant Professor
OBJECTIVES Discuss athletes concerns regarding weight loss & weight gain Provide recommendations for healthful weight loss & weight gain strategies for athletes Describe body composition concerns Describe physiological mechanisms that effect body weight and appetite changes. Identify athletes at risk for body image and eating disorders.
BODY WEIGHT CONCERNS FORATHLETES Effect on performance Appearance/body image Weight class for weight dependent sports Managing body composition Increasemuscle mass Decrease fat mass
ATHLETES & OBESITY Athletes are less likely to be obese than the general population Athletes at risk include: Football players Wrestlers (heavyweight division) Boxers (heavyweight division) Field events (e.g., throwers) Power lifters/strong man
BEFORE MAKING WT GAIN/LOSS RECS Assess appropriate weight & body composition Evaluate diet & exercise patterns Determine energy & macronutrient needs Develop a plan based on needs & goals Educate the athlete & monitor See table 11.4 for more considerations
BODY COMPOSITION Indicator of % body fat Fat mass: weight of body fat, 10% water Essential fat - required for normal functioning Central nervous system, organs 3-5% men 12-14% women Nonessential fat – adipose tissue Fat-free mass: everything except fat, 70% water Lean body mass: includes essential fat
BODY COMPOSITION (CONTINUED) Preferred over BMI for assessing athletes Influencing factors Genetics Gender Age Disease Diet Activity level Weight is not a good indicator of body composition
BODY COMPOSITION (CONTINUED) Monitor in athletes to determine loss of lean or fat mass LBM loss is associated with: Decreased metabolism Decreased strength & power Monitor changes over time in addition to weight Set individual body composition goals, not team goals
RESEARCH/UNIVERSITY SETTING CLINICAL PRACTICE SETTING Underwater weighing Bioelectrical impedance Based on density of fat & analysis FFM, water volume displacement Fat impedes electrical Standard error +/- 2.5% current Air displacement More fat = > impedence plethysmography Muscle transfers current BodPod quickly Used by some professional Highly affected by hydration sports teams Standard error +/- 5% Standard error +/- 2.5% Dual X-ray absorptiometry Skinfold measurement Accurate, whole body Standard error +/- 3-4% with composition good techniqueBODY COMPOSITION MEASURES
BODY COMPOSITION RECOMMENDATIONS Males 10-20% Females 20-30% Optimal levels may vary by sport & individual Reaching “optimal” levels does not guarantee improved performance Low body fat/weight preferred for sports such as: Gymnastics, track, figure skating, ballet High body fat/weight preferred for sports such as: Football linemen, wrestling, cold water swimming, rugby
BODY FAT & PERFORMANCE Excess fat is generally a disadvantage for athletes Hinders vertical jumping, running, rotation Reduces speed & acceleration Increases metabolic cost of activity & reduces aerobic capacity The exception may be long-distance swimming where body fat helps with buoyancy & insulation
ESTIMATE ENERGY NEEDS Cunningham Equation: REE = 500 + 22xFFM(kg) Total Daily Energy Expenditure (TDEE) = REE + NTEE + PAE Resting Energy Expenditure (REE) = 500 + 22 x fat free mass in kg Non-training energy expenditure (NTEE) = activity factor x REE Light activity = REE x 0.3 Moderate activity = REE x 0.4 Heavy activity = REE x 0.5 Physical Activity Expenditure (PAE) = kcal/min x min of activity See table 11.6 of your text
CUNNINGHAM EQUATION EXAMPLEAthlete with 47.3 kg fat free massTDEE = REE + NTEE + PAE REE = 500 + (22 x 47.3 kg) = 1540 NTEE = 1540 x 0.3 (for light daily activity) = 462 PAE = 10 kcal/kg/hr (cycling at 15 mph) x 61.4 kg = 614 kcal/hrTDEE = 1540 + 462 + 614 = 2616 kcal
ENERGY & WEIGHT LOSS Calorie restriction can lead to: Lower metabolic rate Lower thermic effect of food (TEF) due to less total food intake PRO & CHO have > TEF than fat Loss of lean body mass Lower levels of satiety hormones (leptin) Higher levels of hunger hormones (grehlin, neuropeptide Y, glucagon) Higher metabolic efficiency which inhibits weight loss hormones (leptin, cholecystokinin, insulin)
ENERGY & WEIGHT LOSS Metabolic efficiency – genetically determined (??) Low efficiency resists fat gain (people who eat everything & never gain a pound) High efficiency stores fat (people who look at food & gain weight) Thermic Effect of Activity (TEA) May exceed resting metabolic rate & make up the greatest % of energy expended for some athletes High levels may lead to weight loss
WEIGHT LOSS FOR ATHLETES 3 options: Challenges:1. Decrease calorie 1. Athletes already intake exercise a lot2. Increase calorie 2. Meeting PRO & CHO expenditure needs for proper3. Both 1 & 2 recovery 3. Maintaining energy levels 4. Preventing hunger
RECOMMENDATIONS Compare estimated kcal needs to actual intake Decrease no more than 250-500 calorie per day from actual intake Discuss portion control for kcal lowering Eat regular meals Plan for pre & post exercise meals or snacks within kcal needs
RECOMMENDATIONS (CONTINUED) Maintain adequate CHO within kcal restriction Too low will hinder performance Limit low nutritional value CHO Choose nutrient dense & high fiber CHO Maintain adequate PRO for tissue repair & satiety Muscle maintenance critical for physical performance Choose lean, low-fat options Reduce fat intake ~20% of kcal
RECOMMENDATIONS (CONTINUED) Attempt weight loss in off-season Smaller meals & snacks more frequently Timing important for sustained energy levels Consider kcals from sports drinks & use appropriately
BEHAVIORAL MODIFICATIONS Increase physical activity throughout the day Adjust intensity & duration of exercise Encourage self-monitoring Food diaries Exercise/training logs Sport performance measures
MOTIVATION Focus on performance oriented goals Personal best times Increased strength Energy levels Body composition - monthly Weight measures - weekly
WEIGHT CLASS SPORTS Consequences of weight cutting: Electrolyteimbalances Low blood volume/dehydration Cardiovascular strain Poor body temperature regulation Renal function abnormalities Hypoglycemia Fatigue & decreased mental stamina/focus
ATHLETES & DISORDERED EATING Athletes at risk Subjectively judged – diving, skating, gymnastics, dance Minimal clothing – track, swimming, volleyball, dance, skating Lean body emphasis – long-distance running, ballet Weight class sports Pressure to attain the “ideal” in their sport Social physique anxiety Pressure from others Coaches, parents, trainers, teammates
TYPES OF EATING DISORDERS Anorexia nervosa Bulimia nervosa Eating Disorder-Not Otherwise Specified (EDNOS) Anorexia Athletica – no official DSM-IV criteria for diagnosis Continuum of behaviors may lead to above diagnosis
ANOREXIA NERVOSA Severe calorie restriction; energy drain Significant weight loss Refusal to maintain normal, healthy weight Intense fear of weight gain Distorted body image Amenorrhea
BULIMIA NERVOSA Binge episodes Out of control Inability to stop eating despite being overly full Inappropriate compensatory methods Vomiting, laxative abuse, over-exercise, fasting Distorted body image; influences self-esteem Usually normal body weight
ED: NOT OTHERWISE SPECIFIED Eating disorder that does not meet all criteria for anorexia or bulimia Allows for description of a variety of eating disturbances that negatively affect daily life
SIGNS OF ANOREXIA ATHLETICA energy intake Bingeing & purging weight GI complaints Maintain high Menstrual dysfunction performance level Compulsive exercise Desire for weight loss Poor view of self-worth based on performance Does not meet all not appearance criteria for ED but has Fear of weight gain many characteristics Weight cycling
EFFECTS OF ED ON PERFORMANCE Decreased fat-free Anxiety mass (muscle loss) Inability to sleep Dehydration Decreased Glycogen depletion concentration Negative hormonal Poor exercise disturbances performance Gastrointestinal problems due to Increased risk for laxative use overuse injuries
OTHER WARNING SIGNS Change in weight Behavioral changes Withdrawal Lack usual competitiveness Reduced self-esteem & confidence Depression & anxiety Restricted diet Nutrient deficiencies: iron, calcium, other V & M Stress fractures
ED (CONTINUED) Female athletes at greater risk Screening tools EDI- eating disorder inventory FAST – female athlete screening tool http://uhs.nd.edu/assets/25319/fem_ath_form_m10. pdf Source: Kimberly Y. McNulty, Cynthia H. Adams, Jeffrey M. Anderson and Sandra G. Affenito. Development and Validation of a Screening Tool to Identify Eating Disorders in Female Athletes, J Am Diet Assoc. 101:886-892, 2001
FEMALE ATHLETE TRIAD (FAT) Disordered/Inadequ May be due to poor intake ate energy intake or excessive energyFAT - Increases risk Expenditure from training of bone fractures & osteoporosisLack of estrogeninhibits calcium Unable to produceabsorption & Osteoporosis Amenorrhea enough estrogenretention
MALES & ED ~ 1,000,000 males have ED Weight class & weight emphasis sports may increase risk Weight lifting & body building associated with disordered eating behavior Concerned with bulk rather than thinness
SIGNS OF MUSCLE DYSMORPHIA Preoccupation with body shape/size Preoccupation interferes with social, occupational, recreational, & functioning aspects of life Excessive exercise Obsesses about food May abuse steroids
TREATMENT OF ED FOR ATHLETES Health care team RD’s role to assess: approach Intake Medical doctor Needs Psychiatrist, Weight status psychologist or Nutritional behavioral therapist adequacy/deficiencies Dietitian Help athlete to Coach/trainer understand how food Parents fuels physical performance Develop rapport & make plan together
PREVENTION PRACTICES Reduce emphasis on ideal body weight and/or body composition Emphasize skills and performance Discourage diets and quick weight loss Modeling of healthy eating by coaches, etc. Develop a healthy gym environment Help set achievable goals Educate coaches & parents
WEIGHT GAIN FOR ATHLETES Aim for muscle weight 3 requirements for gain increasing muscle Increase strength to mass weight ratio 1. Resistance training program 2. Positive energy balance 3. Positive N2 balance
RESISTANCE TRAINING Must overload muscle to stimulate growth Train major muscle groups Train for hypertrophy 8 to 12 reps/set 3 to 5 sets/muscle group 2 to 3 times/week 48 hours between workout to allow for recovery
POSITIVE ENERGY BALANCE 2,300 to 3,600 calories = ~ 1 pound of muscle 300 – 500 extra calorie per day Rate of gain depends on: Genetics Training level – highly trained athletes gain muscle at a slower rate than untrained
POSITIVE ENERGY BALANCE Increase CHO to spare PRO for muscle building Assure adequate calories
POSITIVE NITROGEN BALANCE Recommended PRO = 1.4 to 2.0 g/kg to support muscle growth (> 2 g/kg is not recommended) Supplements: Usually not necessary – assess normal intake first Encourage food sources Extra PRO above needs = extra body fat Special populations – high energy expenditure, vegetarians Consider PRO allergies & lactose intolerance Some products come with banned substances, no rigorous testing required before marketing
ADDITIONAL TIPS FOR WEIGHT GAIN Choose milk & juices as fluids between meals Plan for snacks between meals Choose nutrient & energy dense snacks such as trail mix, energy bars, Boost, Ensure, fruit with peanut butter Use sports drinks instead of water Include bedtime snacks – bowl of cereal, fruit & yogurt smoothie
SUMMARY Weight loss/gain is a concern for many athletes Use BMI with body composition to assess weight status Make modest changes in calorie intake for loss/gain Be aware of disordered eating behaviors Educate on healthy weight loss/gain strategies
REFERENCESFink HH, Burgoon LA, Mikesky AE, eds. Practical Applications in Sports Nutrition. Sudbury, MA: Jones and Bartlett; 2006Thomas LM. Energy balance and weight management. In: Dunford M, ed. Sports Nutrition: A Practice Manual for Professionals, 4th ed. American Dietetic Association; 2006.