Carbohydrate feeding after exercise Flashcards
What is the difference between 2 g/kg carbohydrate immediately post exercise or 2 h post exercise?
Immediately post exercise there are high rates of muscle resynthesis, whereas 2h post exercise there is a blunting on the rate of muscle glycogen resynthesis.
Should the same carb feeding protocol be taken for long-term (8-24h) and short-term (0-8h) recovery?
No.
Long term - Adoption of general daily CHO intake should ensure repletion on
day-to-day basis.
Short term - More specific strategies may
help ensure rapid glycogen repletion.
What are carb targets for light (Low intensity or skill-based
activities) activities?
3-5 g/kg/d
What are carb targets for moderate activities?
5-7 g/kg/d
What are carb targets for high intensity (Endurance programme (e.g.,
moderate-high intensity exercise of 1-3 h/d)) activities?
6-10 g/kg/d
What are carb targets for very high intensity (Extreme commitment (i.e., moderate-high intensity exercise of >4-5 h/d)) activities?
8-12 g/d
Glycogen re-synthesis has 2 phases, what are they?
- Insulin independent (rapid phase)
- Insulin dependent (slow phase)
When your muscle contracts, what 3 factors are involved in the regulation of glycogen resynthesis, and what do they do??
- Ca2+NO
- adenosine
- AMPK
These increase GLUT4 translocation, increase glycolysis rates, and reduce glycogen synthase activity.
When is the optimal time for carbohydrate ingestion post exercise?
Immedietely post exercise - evokes a greater rate of glycogen synthesis than carb ingested 2 hrs after exercise
In terms of the amount of carb intake, above ? g/kg bw/h is there little or no benefit?
1.2 g/kg bw/h
Carbs with a ? glycaemic index provide a readily available source of substrate for glycogen synthesis.
Moderate-to-high glycaemic index.
This may be important when maximum glycogen storage is required in the hours after an exercise bout.
Do glucose, sucrose and fructose all increase muscle glycogen content the same post-exercise?
Glucose and sucrose increase it roughly the same, however fructose increases it only half of the other two.
If you want speedy refuelling after exercise, what is the best way to go about it?
Early and frequent carbohydrate feeding (e.g., within the first hour and at 30 min intervals for 4 h thereafter, before resuming normal diet).
1.2 g/kg CHO/h for first 4 hours, of moderate-to-high glycaemic index CHO’s.
Addition of protein if CHO intake is sub optimal (but probably some protein anyway for stimulation of MPS.)
What are the benefits of post-exercise glucose+fructose instead of just glucose with regards to glycogen synthesis rates?
4h glycogen synthesis rates in the muscle are very similar. However, 6h liver glycogen synthesis rate almost doubles with a glucose + fructose diet.
