Fat

Question 1

Fat is an important fuel during X exercise

Answer 1

Endurance.
The ability to oxidize fat is correlated with perofrmance.

Question 2

What is a rate-limiting factor of fatty acid oxidation?

Answer 2

• NOT delivery of FA
• NOT absorption of FA
• YES: FA transportation into the mito’s, most limiting

Question 3

X is the inhibitor of CPT1

Answer 3

Malonyl-CoA (malonyl-CoA can enter liplysis, so a negative feedback system i guess: we have enough)

Question 4

• All activity of fat oxidation takes place here:

Answer 4

in mitochondria: so number of mito’s is important

Question 5

 Regular endurance training decreases lipid oxidation and decreases CNS (central nervous system) activity

True/false

Answer 5

False: lipid oxidation is increased. Promote oxidation lipid-based fuels, and slower utilization of CHO-based fuels
-> “glycogen sparing”

Question 6

What does exercise (endurance) training do with mito’s and CHO metabolic enzymes?

Answer 6

• Increased mitochondrial volume and enzymatic adaptations
• Reduction in signals that activate major CHO metabolic enzymes
  -> But substrate availability (diet) also plays a role !

Question 7

In the muscle, there is a local release of …., … , …. & … to name a few , with training adaptation

Answer 7

cytokines, GF, hormones, ROS

Question 8

What are three nutritional strategies, that have been stated to improve lipid oxidation

Answer 8

1. ‘boosting’ fat oxidation
2. fat adaptation
3. ‘periodically’ train with low CHO availability

Question 9

What are examples of substances that ‘boost’ fat oxidation

Answer 9

• LCFA (slow gastric emptying)
• MCFA (rapid gastric emptying)
• Caffeine (adrenalin-like effect: can stimulate lipolysis)
• L-carnitine (theoretically it could make sense. It should increase the muscle pool, but it is questioning whether this is really happening.)

Question 10

2. fat adaptation (Diet change): what can you do?

Answer 10

Low carb high fat diet
–>results in less reliance on CH and more fat oxidation. However:

> Metabolic adaptation
● Improved lipid metabolism/oxidation
● Low glycogen, lower activity CHO metabolism (PDH)
-> Unable to train/exercise hard, impaired adaptation, impaired performance

Question 11

What are three scenarios where adaptation to LCHF diet is favorable?

Answer 11

• when having prolonged sub-maximal effort, with no benefit for higher-intensity pieces
• difficult to consume adequate CHO to meet goals for optimal CHO availability
• CH sensitive and likely to be exposed to low CHO availability

Question 12

What other diet strategy is used?

Answer 12

ketogenic diets-> alternative energy substrate. May alter metabolism, but insufficient understanding to use them as ergogenics

Question 13

3. ‘periodically’ train with low CHO availability: what is the idea of this concept?

Answer 13

(occasionally) training with low CHO availability (low strategies; ‘tain low’) wil ‘ramp up the signal’:
Extra stimulation of metabolic pathways that trigger mitochondrial biogenesis (via PGC1a), which will benefit both fat oxidation and glycogen storage

Question 14

Does this concept of low and high work?

Answer 14

Enhanced metabolic adaptation (~75%of studies)
● Increased ability utilize fat, reduced reliance CHO

Side effects – low CHO availability:
● Reduced ability to train at high intensity
● Negative impact on Immune function/ Central nervous system (overtraining)

–> In most instances No Performance benefit (63% studies)