Module 3: Energy Balance and Weight Management for Athletes Flashcards
Define energy balance
The mathematical relationship between energy intake and energy expenditure
- Energy balance = energy intake - energy expenditure
What is energy intake?
- Sum of the calories (food energy) that an individual takes in per day
- It describes the quantity of calories but does not address the behaviors that underpin energy intake
Define energy expenditure
- Energy expenditure describes the quantity of calories (food energy) used by the body per day
- Multi-factorial and influenced by a variety of things (mor complex)
When will there be a weight loss and weight gain?
- Weight loss: EE>EI (negative energy balance)
- Weight gain: EI>EE (positive energy balance)
What is energy intake influenced by?
- Influenced by multiple social and behavioral factors
- In a condition of food security, humans eat rather than feed
- Humans should just eat when hungry and stop when full in theory
- Factors influence the amounts and types of foods people eat or their eating pattern such as mental health issues, hormonal drivers to eat, social eating (birthdays, social events)
Teaching people what to do does not always mean….
That they will do it! There are things they enjoy that they don’t want to give up
What are the components of energy expenditure?
TEE = REE + NREE
What comprises REE?
- BMR/RMR = Basal or Resting Metabolic Rate
- Although BMR and RMR slighly differ from each other, RMR should be an accurate estimate of your BMR
What comprises NREE?
- NEAT = Non-exercise activity thermogenesis
- TEF = Thermic effect of food (influence on body weight is often overstated)
- EAT = exercise activity thermogenesis
What makes up the largest portion of EE?
- REE makes up majority, EAT makes up very little
- Can upregulate BMR
- NEAT is decreasing with obesogenic environment, conveniences, sitting
- Blue zones: higher NEAT than other areas
What is RMR influenced by?
- RMR is influenced by a wide-variet of factors including body composition and intensity and duration of planned physical activity
- RMR increases with FFM therefore strength training important
What is energy intake and energy expenditure influenced by?
Why do sports dietitians estimate TDEE?
- Establish a standard for energy intake adequacy
- Assess nutritional status
What is used to estimate TDEE?
- Predictive equations
- ONLY an ESTIMATE of an athlete’s energy requirements
- The reliability of the estimate is only as good as the information available to the dietitian
What do predictive equations use?
- Use weight, height, FFM and/or age to estimate RMR
- Research shows most predictive equations tend to underestimate RMR in athletes
- The dietitian will choose the equation they prefer to use and defend
Name predictive equations commonly used. Which have the strongest correlations?
- Owen
- Harris-Benedict
- Mifflin
- Cunningham
- EER
- Harris-Benedict and Cunningham have the strongest correlations. (Cunningham seems to be the best for female and male athletes)
What does the HBE consider?
- Height, weight, age, and gender
- Only an estimate of RMR! Still need to multiply by activity factor for athletes, this is where it gets complicated
What is the conversion of lbs to kg and inches to centimetres?
- 1 lb = 0.454kg
- 1 inch = 2.54 cm
What does mifflin-st Jeor equation consider?
Considers height, weight, age, and gender
When should you round when calculating RMR?
- Rounding is done to the final calculated value ONLY
- Serial rounding detracts from the estimate
- Standard rounding conventions are used (38→40; 33→30)
- If a range is offered it is given as a span of either 50 or 100 (1762.18 → 1750-1800 or 1750-1850)
What is an activity factor and what is the factor for sleeping/sitting/lght activity/light training/heavy training?
- A value that is applied ON TOP of RMR to account for NEAT and EAT
- To accurately estimate the contribution of both NEAT and EAT to the athlete’s TDEE, we collect information on the athlete’s activity levels across their entire day
Once you have calculated the AF of an athlete what do you do?
- Divide the total amount by 24 hrs to get the AF
- Multiply the RMR by the activity factor to get their TDEE
Michael Phelps estimated energy intake is 12,000kcal/day. Why is it so high?
- Energy requirements in elite athletes can be very high
- Would have a high RMR due to size and amount of FFM
- Engaging in high intensity, would have a large AF
- EE would be extremely high thus justifying need for energy intake to be extremely high
What are the estimated energy requirements by sport?
How many calories due winter olympic athletes eat?
If an athlete wants to gain weight via muscle gain how must their energy requirements change?
- To accrue additional muscle mass, an athlete must be in positive energy balance
- Calories, more so than protein, are the critical factor in muscle mass accretion
- Goal = TDEE + 400 to 500kcal/day
- To facilitate ongoing gains, energy requirements must be adjusted regularly (because RMR keeps increasing)
If an athlete is wanting to lose weight via fat loss how must their energy requirements change?
- To lose body fat, an athlete must be in a negative energy balance
- Care needs to be taken to avoid excessive energy balance which could harm performance and lay down foundation for RED-S
- Goal = TDEE - 500 to 700kcal/day
- To reduce the risk for under-fueling and inadequate performance, weight loss should be the focus of off-season training only
What is periodization?
- Fueling for the work required, in a meal-by-meal and day-to-day manner
- It is aligning the volume and type of food intake with the volume and type of training with the goal of enhancing sport performance
- “the planned, purposeful, and strategic use of specific nutritional interventions to enhance the adaptations targeted by individual exercise sessions or periodic training plans, or to obtain other effects that will enhance performance long term”
- Want to look at whole and then break down into workable parts
What are the 3 periods of periodization?
- Macroperiodization
- Mesoperiodization
- Microperiodization
Define macroperiodization
The macrocycle is the athlete’s long-term or seasonal training plan. Macroperiodization is an approach to dietary modification that spans weeks and months to an entire year and encompasses all of the training that an athlete will take part in. It begins with the start of training and ends with the athlete’s goal event.
Define mesoperiodization
Mesocycles are four to six week cycles within the macrocycle and are typically referred to as blocks. In a typical four week block, the first 3 weeks progressively overload your body, while the 4th week focuses on recovery. Mesoperiodization recognizes this and works to align the athlete’s diet within each block to reflect the gradual increase in training stress.
Define microperiodization
Microcycles are the simplest and shortest way of looking at an athlete’s training cycle. A microcycle is a single week within a macrocycle. It describes the types of workouts, specifically, that the athlete will complete. The goal of microperiodization is to support the athlete’s nutrient intakes and align with their daily workouts, matching nutrients with the workout type, intensity, and duration
Periodized diet plans for athletes ideally encompass…
All three parts of the periodization cycle
What is the approach to dietary periodization?
There is no standard approach to dietary periodization
- sport is diverse. Individual athletes are diverse in their physical response to training. Training approaches are diverse
- Trial and error with re-evaluation is important
Why is a periodized training schedule important?
- It provides the framework for the sport dietitian to match any nutritional strategies to the desired training outcomes
- You have to have a deep understanding of the athlete’s training program and it’s desired goals to successfully build a periodized eating plan
What is the major determinant of an athlete’s energy expenditure?
- EAT is often a major determinant
- EAT can vary considerably based on the athlete’s training load across micro-, meso-, and macrocycles of the training plan
How should EI of athletes vary across time?
- Should vary between days, weeks, and training phases to align with training demand and other goals:
- Transformation of body composition
- Periodization of EI has boundaries and cannot be designed such that it presents the risk for insufficient EA and RED-s
When was the Female athlete triad recognized?
- Originally described in 1992
- First recognized as three separate but related conditions
- Now recognized by the American College of Sports Medicine (ACSM) as a spectrum of related symptoms and conditions that can impact female athletes
What is the female athlete triad?
- A syndrome of three interrelated conditions:
1. Relative Energy Deficit (with or without disordered eating)
2. Menstrual Disturbances/ Ammenorhea
3. Bone loss/osteoporosis - The triad threatens both sport performnce and the athlete’s health (physical and mental)
- Relative deficit in energy intake is the trigger
What is a relative energy deficit?
- Standard formula for the estimation of energy requirements were largely validated on general population
- Athletes have higher FFM compared to less active people even at the same body weight
- More FFM = more metabolically active tissue = higher BMR = Higher basal energy requirements
- Relative energy describes an approach where energy needs factor consider variations in FFM
- The estimate is relative to the athlete’s body composition and FFM levels
What are the constituents of FFM?
- SM mass, body cell mass, total body water, and bone mineral mass
What is the spectrum of the female athlete triad?
- Spectrum of symptoms that range
- Can have one side where there is optimal energy availability, optimal bone health, eumenorrhea
- Then can span down until there is osteoporosis, low energy availability, and functional hypothalamic amenorrhea
What is ammenorhea associated with the FemAT driven by?
Driven by low energy availability and negative changes to hypothalamic function
What are the types of ammenorhea and explain each
- Primary ammenorhea → Absence of menstruation by age 16 in a girl with secondary sex characteristics
- Secondary ammenorhea → Absence of 3 or more consecutive menstrual cycles in a female who has begun menstruating
What effect does low energy availability have on the body in the FemAT?
- Low energy availability disrupts the hypothalamic-pituitary-ovarian axis
- Decreaase in GnRH from hypothalamus disrupts pituitary secretion of LH and FSH
- Disruption of LH and FSH shuts down stimulation of the ovary ceasing production of estradiol
- Low estradiol level creates a hormonal environment that mimics that seen in menopause (ammenorhea and loss of bone mass/osteoporosis)
What is the solution to hypothalamic dysfunction and thus the FemAT?
- Remedying the low energy intake by slowly incorporating more foods so symptoms turn around
How is bone health impacted in the FemAT?
- Female athletes have a higher BMD than nonathletic counterparts UNLESS they have menstrual dysfunction
- Risk of stress fractures is 2-4x higher in amennorheic athletes
- Bone density declines in proportion to the number of menstrual cycles missed
→ Myburgh and colleagues showed a direct correlation between time spent amenorrheic and number of stress fractures in 1990 - Low bone mineral density may be irreversible resulting in a lifetime of LBD
What is osteoporosis?
- Chronic condition characterized by low bone mass and microarchitectural detioration of bone tissue leading to enhanced skeletal fragility and increased risk of fracture
- Principal cause of premenopausal osteoporosis in active women is decreased ovarian hormone production and hypoestrogenemia
- Athletes may be at risk for fractures during their competitive years and premature osteoporotic fractures in the future
- Causes weak bones via loss of minerals (calcium)
- Bones become fragile and break easily (trabecular bone disrupted)
Why was the broader term RED-S developed?
- Scientific evidence and clinical experience show that low energy availability has effects that extend far beyond menstrual function and bone health (occur in men as well)
- In 2014, the IOC introduced a more comprehensive broader term for the overall syndrome: Relative Energy Deficit in Sport (RED-S)
Define RED-s
- RED-s refers to impared physiological functioning caused by relative energy (calorie) deficiency
- The significance of the energy deficit is relative to the athlete’s FFM (metabolically active mass)
What impairments may be caused because of RED-S?
Physiological effects include impairments to:
- Metabolic rate
- menstrual function
- bone health
- immunity
- protein synthesis
- heart health
What are the health consequences of RED-s?
What are the potential performance effects of RED-s?
When does RED-S occur?
- When an athlete suffers from low energy availability
- Insufficient energy intake to support the EE required for health, basic physiological function, and daily living, once the cost of exercise and sporting activities is taken into account
- Can occur with or without a diagnosed eating disorder being present
Do you need to have an eating disorder in order to have RED-S?
- Does not require an eating disorder
- Inadequate caloric intake
→ Pathologic caloric restriction
→ Expending more calories than are taken in
How do you calculate energy availability?
Energy availability = (Calories consumed - calories expended)/FFM
- Normal >45kcal/kg
- Negative effects at less than or equal to 30kcal/kg
What does a BMI of <17.5kg suggest?
- Suggestive of low energy availability
- Adolescents <85% Estimated Body Weight
Can male athletes have RED-S?
- Male athletes can also suffer from low energy availability
- Evidence shows male cyclists and ski jumpers have low energy intake and have high prevalence of being underweight
- Male athletes are at lower risk for developing disordered eating and eating disorders but these conditions are not exclusive to women
- Disordered eating, eating disorders, and low energy availability (without an ED) are associated with LBMD and stress fractures in male athletes
How can you assess RED-S in an athlete?
- Screening using RED-S risk assessment moldel as part of regular health checks or when presenting the following symptoms:
- DE/ED
- Significant weight loss
- Lack of normal growth and development
- Endocrine dysfunction
- Recurrent injuries and illness
- Decreased performance/performance variability or
- Mood changes
What is the treatment for low energy availability?
- The treatment of low EA should involve an increase in EI, reduction in exercise or a combination of both
- A reasonable starting treatment approach to address low EA is to implement an eating plan that increases current EI by ~300-600kcal/day and address issues such as meal timing and food choices
- Should be paired with reductions in training volume and intensity
What is the treatment for menstrual irregularities?
- Weight gain is the strongest predictor of recovery of normal menstrual cycles
- An eating plan that promotes adequate protein and CHO intake is recommended to restore liver glycogen and, in turn, facilitate normalization of hypothalamic function
What is the treatment for bone demineralization?
For Female athletes:
- Weight gain with or without the subsequent resumption of menses restores the coupling of bone formation and resorption and improves BMD
- However, full recovery may not be feasibe, as bone microarchitecture can be permanently damaged
For males and females:
- The athlete’s diet should include 1500mg/day of calcium from dietary sources with supplementation if required PLUS 1500-2000 IU/day of Vitamin D
