Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NASM CSNC > Chapter 6 - Energy Balance and Availability > Flashcards

Chapter 6 - Energy Balance and Availability Flashcards

You may prefer our related Brainscape-certified flashcards:
NASM ® CPT flashcards
1
Q

energy balance

A

balance between energy expenditure and energy intake

For the athlete, even short-term variations in energy balance (and, thus, in body mass) can have a dramatic impact on performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

metabolizable energy

A

differences between the absolute energy of ingested food and any energy lost in feces and urine

The metabolizable energy of each macronutrient is approximately:
* 4 kcal/g for carbohydrate
* 4 kcal/g for protein
* 9 kcal/g for fat
* 7 kcal/g for alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

thermic effect of alcohol

A

7 kcal/gram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

direct vs. indirect calorimetry

A

direct: necessitates use of a process called direct calorimetry and highly controlled lab conditions

indirect: the type and rate of substrate utilization are measured from gas exchange measurements (carbon dioxide production and oxygen consumption) during both rest and steady state exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

examples of CSNC-available calorimetry estimate equations

A
  1. Harris Benedict
  2. Mifflin-St. Jeor
  3. Activity Factors (AF) (Multiply BMR x AF to get Estimated Energy Requirements (EER)

Little to no exercise: EER = BMR x 1.2 (for in bed); for out of bed but low activity, use 1.3
**Light exercise **(1–3 days/week): BMR x 1.375
Moderate exercise (3–5 days/week): BMR x 1.55
Heavy exercise (6–7 days/week): BMR x 1.725
Very heavy exercise (e.g., 2 workouts/day; intense workouts or athletic training): EER = BMR x 1.9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

components of energy expenditure

A
  1. BMR (RMR) (60-70% of TDEE for basic physiological functions)
  2. excercise activity thermogenesis (~30% for average athletes)
  3. ** thermic effect of food** (~10% of TDEE)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

component of energy expenditure

resting metabolic rate

A
  1. largest component of energy expenditure (60-70% of TDEE)
  2. Different tissues within the body have distinctly different resting energy requirements. For example, organs such as the liver, gut, brain, kidney, and heart have high energy requirements and account for approximately 75% of resting metabolic rate.

Despite skeletal muscle comprising almost 40% of total body weight, muscle has a much lower energy requirement than these vital organs and comprises only 20% of resting metabolic rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

component of energy expenditure

activity thermogenesis

A
  1. activity and non-activity thermogenesis
  2. by far the most variable component of daily energy expenditure
  3. 30% of total daily energy expenditure and, in some cases, can be as high as 70–80%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

energy availability

A

Energy availability = (Energy intake – exercise energy expenditure) ÷ fat-free mass

example with a cyclist:

Energy intake (8,000 kcal) – exercise energy expenditure (5,600 kcal) / fat-free mass (70 kg)

Energy availability = (8,000 – 5,600) / 70

Energy availability = 2,400 / 70 = 34.3

EA = 34.3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

daily energy balance vs daily energy availability

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

optimal energy availability in athletes

A

Though optimal levels of energy availability in athletes are not currently known, an energy availability of
1. 45 kcal/kg fat free mass (FFM) per day for females
2. 40 kcal/kg FFM per day for males

provides a threshold to maintain normal physiological function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

low energy availability (LEA)

A

A state in which insufficient energy is available for normal physiological functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

amenorrhea

A

The absence of menstruation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

functional hypothalamic amenorrhea (FHA)

A

A form of amenorrhea and a chronic absence of ovulation

athletes who compete in weight-sensitive sports and/or sports that require high levels of energy expenditure seem to be at higher risk of LEA. In contrast, LEA is less prevalent in athletes who compete in sports where daily energy requirements are significantly lower and there is less importance placed on overall body size and composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

consequences of LEA

A
  1. Disruptions to reproductive function and sex hormone production
  2. Increased risk of low bone mineral density
  3. Alterations in metabolic rate
  4. Reduced psychological well-being
  5. Reductions in performance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

menarche

A

first occurence of menstruation

17
Q

consequences of LEA

reproductive dysfunction

A

LEA reduces sex hormones associated with fertility in both male and female athletes

females may experience a delayed menarche

18
Q

consequences of LEA

impaired bone health

A

reduced bone mineral density, decreased estimates of bone strength, and increased risk of bone stress injuries

19
Q

consequences of LEA

alterations to metabolic rate

A

LEA is also associated with a reduction in RMR in both female and male athletes

For example, a 2019 case study following the weight-making practices of a professional MMA fighter reported a 330 kcal reduction in resting metabolic rate after just 7 weeks of reduced energy availability

20
Q

consequences of LEA

cardiovascular function

A

Sustained LEA causes changes in circulating hormones that have a direct impact to cardiovascular health

21
Q

consequences of LEA

GI issues

A

Chronic periods of energy deficiency are thought to cause atrophy of mucosal tissue within the intestine, which manifests into various gastrointestinal issues such as bloating, cramping, and constipation

22
Q

consequences of LEA

immunity

A

The immune system may also be altered by LEA, which may cause athletes to miss more training days

For example, observational studies of elite athletes presenting with LEA report an increased likelihood of illnesses, body aches, and head-related symptoms

23
Q

consequences of LEA

hematological issues

A

Poor iron status is often associated with LEA.

24
Q

consequences of LEA

growth and development

A

Alternations in hormones that play an important role in growth and development, such as growth hormone and insulin-like growth factor (IGF-1), have been observed in amenorrheic athletes

As a result, sustained periods of LEA may potentially impair the maturation of youth athletes

25
Q

consequences of LEA

performance

A

In addition to the observed health effects of LEA, performance can also be negatively impacted through indirect mechanisms such as reduced recovery and muscle function impairment.

26
Q

consequences of LEA

psychological issues

A

Various aspects of psychological well-being can also be impacted by LEA

female athletes who present with FHA have been found to have a higher incidence of mild depressive traits, social insecurity, and fears of weight gain

27
Q

calculate energy availability

A

Energy availability = (Energy intake – exercise energy expenditure) ÷ fat-free mass

Using the example of the cyclist above, the following calculates the rider’s energy availability:

Energy intake (8,000 kcal) – exercise energy expenditure (5,600 kcal) / fat-free mass (70 kg)

Energy availability = (8,000 – 5,600) / 70

Energy availability = 2,400 / 70 = 34.3

EA = 34.3

28
Q

energy availability categories

A

TABLE: Energy Availability Categories
Energy Availability

Male/Female
High
Above 40 kcal/kg FFM
Above 45 kcal/kg FFM

For healthy weight gain or maintenance

Optimal
Above 40 kcal/kg FFM
Above 45 kcal/kg FFM

For weight maintenance providing adequate energy for all physiological functions

Subclinical
30–40 kcal/kg FFM
30–45 kcal/kg FFM

May be tolerated for short periods during a well-constructed weight loss program

Clinical
Below 30 kcal/kg FFM
Below 30 kcal/kg FFM

Note. Units for Male and Female measures above in kcal/kg FFM.

29
Q

Harris Benedict Equation for BMR

A

Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)

Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

components are:
weight in kg
height in cm
age in years

30
Q

activity factors for varying leves of exercise

5 total categories

A

* Little to no exercise: EER = BMR x 1.2 (for in bed); out of bed but low activity, use 1.3
* Light exercise (1–3 days/week): BMR x 1.375
* **Moderate exercise **(3–5 days/week): BMR x 1.55
* Heavy exercise (6–7 days/week): BMR x 1.725
* Very heavy exercise (e.g., 2 workouts/day; intense workouts or athletic training): EER = BMR x 1.9

31
Q

EER equation (estimated energy requirement)

A

activity factor x estimated BMR

32
Q

thermic effect of food

A

increased energy expenditure in response to digestion, absorption, metabolism, and storage of food

fat storage as adipose tissue: approximately 3% of the energy of the ingested meal
carbohydrate storage as glycogen: requires up to 7%
Protein synthesis and breakdown: approximately 24% of the available energy

33
Q

screening athletes for LEA

A
  1. subjective symptoms - low mood, irritability, and feelings of fatigue
  2. body composition - excessively low body fat for prolonged periods or massive weight-loss in a short period
  3. clinical assessment - can be used to identify hormone defficiencies
34
Q

treating LEA

A

CSNCs use a combination of
1. increased energy intake
2. decresed energy expenditure

they typically vouge for the former because decreasing training load can result in detraining effect

35
Q

What percent of high school female athletes regularly skip meals to lose weight?

A

23%

36
Q

What appears to be responsible for LEA among high school athletes?

A

ideal body type

NASM CSNC (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions