Energy Balance & Fuelling with Carbohydrate Flashcards
What are the in and out for the energy balance?
IN: Carbs, alcohol, lipids, protein
OUT: Basal metabolic rate, physical activity, foods themic effect, thermoregulation
What happens to an athletes energy needs in a hot, humid environment?
energy needs go up
What are the consequences of negative energy balance?
**Energy input < energy output **
Causes:
1. Insufficient food intake
2. Extreme physical activity
3. Illness or disease (e.g., cancer)
Outcome:
- loss of muscle tissue
- loss of fatt mass (weight loss)
- insufficient intake of essential micronutrients and amino acids for protein synthesis
What might a loss of muscle, fat mass, and nutrient do an athlete?
Increased injury
Fatigue
Increased infection/illness
Poorer food relationships
Impaired growth
What are the four steps of adequate energy is our prioity in sport fueling?
Energy balance
Micro-nutrient
Timing
Supplements
What are the consequences of positive energy balance?
Energy input > energy output
Causes for positive energy balance
1. Excess caloric intake
2. Insufficient energy output for number of calories eaten
Outcome:
* Gain of muscle
* Gain of adipose tissue (weight gain)
* Fill glycogen stores
Consequences of positive energy balance for an athlete
Improve muscle synthesis
Improve energy output
Cause GI distress
- more fatigue
- depending on training goal
How do we measure energy balance in athletes?
Dietary intake + Energy expenditure = Energy Balance
Dietary Assessment
24 hours recall
Food Frequency Questionaire (FFQ)
Food record
‘Gold Standard’
- 24 hrs recall & accelerometer
How to measure energy expenditure?
Activity log
Accelerometer/wearable
O2 output
Heartrate output
What are the two main components to our body composition?
- Fat mass
- Fat-free mass
Fat mass
mostly triacylglycerol & other lipids in adipose tissue
* Anhydrous, less dense
Fat-free mass
muscle, bones, intra- and extracellular fluids
* ~73% water, more dense
What is the difference between fat mass and fat-free mass?
- Water and electrolyte content
- Ability to conduct an electrical current
- Density
What are the body composition measurements?
Anthropometry
Electricial conductance
Densitometry
Absorptiometry
Strength-based
Anthropometry
- Quick and easy; inexpensive
- not difference towards muscle mass
Measured by: - BMI (Body mass index)
- skin fold thickness
- waist circumference
Electricial conductance
- difference in water; density; expensive
Measured by - Bioelectric impedance analysis
Densitometry
- expensive, unconfortable
Measured by: - underwater weighing
- bod pod
Absorptiometry
Dual enegy X-Ray (DEXA)
‘Gold Standard’
Strength-based
- muscle strength
- performance of the muscle, from fatigue and contractability through example squat jumps
Measured by: - Exertion test
- Muscle biopsy
What are the pros & cons of using body composition as a measure of energy balance?
Pros:
- cheap
- can look at muscle itself
- quick
- lower althlete burden
Cons
- lag in changes
- no gold standard in composition
- body fixation
Energy availability (EA)
- reduced by a substantial margin (i.e., by ∼33%) without negative
consequences to health
Measuring individual nutrient & energy needs is very difficult - mean magnitude of errors of estimation of energy intake (EI), energy
expenditure of exercise (EEE), and total energy expenditure (TEE) can be in
the order of 1,200–2,500 kJ/day (300– 600 kcal/day)
What are CHO status?
Total intake
CNS needs
Muscle needs
Timing
High CHO availability
Have enough CHO for muscle & CNS needs in relation to intake and timing of exercise
