W3 - Fat & Performance (new) Flashcards
What is the major storage from of fats in the body?
TAG
3 FA + 1 glycerol
No. of C in SCFA
4 or less
No. of C in MCFA
6-12
No. of C in LCFA
14+
The longer the FA chain length the…
More solid it is at room temp
What are the missing H bonds in unsat FA replaced by?
C=C
Which type of FA have all their H bonds?
Saturated
What do trans fats do?
Increase LDL content
Decrease HDL content
= Negative effect on health
Which FA NEED to be consumed due to not being able to be synthesised by the body?
Essential
What does the 9 in Omega-9 symbolise?
9 C’s away from the omega end of the FA chain
Which omegas are essential FA that we must consume through our diet?
3
6
What does the ratio of n-3/n-6 poly-unsat FA in cell membranes lead to?
Different sets of intracellular mediators being produced.
Which poly unsat FA leads to FEWER inflammatory mediators being produced?
n-3
What happens to the turnover rate of adipose tissue if health status declines?
Will also decline
Athlete use + re-synthesis of adipose tissue
Extremely fast
Which FAs can be found in circulation?
MCFA + LCFA
What can happen to the MCFA and LCFA found in circulation?
Can be transported into cell via FD through FAT/CD36.
Which FA can also be found as IMTG?
LCFA
Once into cell, what happens to the MCFA?
CoA facilitates reaction of MCFA to Acyl-CoA
Once into cell, what happens to the LCFA?
CoA facilitates reaction of LCFA to Acyl-CoA with ACS.
What happens in the cell once MCFA have been converted to Acyl-CoA?
Acyl-CoA can diffuse into mitochondria.
What happens in the cell once LCFA have been converted to Acyl-CoA?
Acyl-CoA can be translocated into mitochondria via Carnitine shuffle by CP1, CACT + CPT2 enzymes.
What happens once Acyl-CoA formed from MCFA or LCFA enters mitochondria?
Undergo b-oxidation:
2C are cleaved off every round to prod Acetyl-CoA which can then be used in oxidative phosphorylation to synthesise ATP.
Roughly at what exercise intensity are Fat AND CHO use roughly equal?
65% VO2 max
What is the most proximal lipid fuel source for the muscle?
IMTG
Where do IMGT exist?
In lipid droplets within + between muscle fibres.
Although athletes might have the same amount of lipids stored in the muscle cells compared to somebody obese, they are stored in different places + different masses.
Explain this
Athletes lipid droplets will be stored directly proximal to mitochondria + their masses will be smaller to provide larger SA for hormones to liberate FFA within = higher turnover of lipids.
Obese ind = more inert lipid droplets w/ a much lower turnover rate.
Is Fatmax fixed?
No, inter-individual variability can be very large
What does training do to fat oxidation?
Enhances it
Roughly at what % Vo2 max does fat oxidation peak?
~50-65%
What is a positive to endogenous fat availability and fat oxidation being increased?
CHO will be spared - available to use at specific times during sporting perf.
What is meant to happen if the drug heparin is co-administered with a high fat meal?
Heparin will increase the release of LPL from vasculature to allow for incr hydrolysis of ingested TAG to FFA.
== More FFA available
Does increasing fat oxidation at moderate exercise intensity improve performance?
NO
A set amount of fat is needed in the diet to maintain IMTG stores but more is…
Not necessarily better as more can lead to impaired glycogen storage
What has data suggested about a very low fat diet and why?
Perf detriment could be likely
Due to reduced IMTG storage.
In order to preserve IMTG content, the daily fat intake for endurance athletes should be no less than…
22%
During exercise above 70% VO2 max, the rate of fat oxidation in skeletal muscle can be limited by what??
Plasma FFA conc
