Nutrition to fuel sports performance
SUMMARY OF LECTURES
Pascal Wischhoff
,Substrate metabolism
There are three substrates, carbohydrates, proteins and lipids. Only carbohydrates and
lipids provide energy for the body. Protein is more used for protein synthesis and not as a
substrate.
Background on CHO
Carbohydrates can be found as saccharides. The
simplest form is a mono-saccharide (e.g. glucose,
fructose and galactose).
Di-saccharides are two mono-saccharides
together.
Poly-saccharide are more than two mono-
saccharides bound together.
Mono-saccharides lead to a quick spike of blood
sugar levels. This is mostly something that you
don’t want since you get energy very quickly and
then your blood sugar levels decrease again.
Poly-saccharides are digested in a slower way and
this leads to a slow absorption and a slow increase
of blood sugar level.
Digestion and absorption of poly-saccharides.
When they are eaten, they first need to be broken down into mono-saccharides. Then they
can be either used for energy in the muscle or it can be stored in the muscle or in the liver
until you need them at a later point.
When you eat something, it first needs to be broken down into Glucose, Fructose or
Galactose (depending on the kind of carbohydrate ingested). Then these mono-saccharides
can be either used for energy or they can be stored in the muscle or liver in the form of
glycogen. Whenever it is needed, glycogen can be converted back into glucose. The liver will
excrete the glucose, travelling to the muscle by the blood vessels where it will be used for
energy. Also, the glycogen in the muscle will be converted back to glucose, where it will be
used for energy directly.
The pathway at which glucose enters the muscle or the liver and how glucose is stored
into glycogen.
Glucose is taken up by Glut2 (glucose transporter) in the liver and Glut4 in the muscle, this is
insulin or contraction mediated. Then glucose will be converted into Glucose-6-phosphate
(in the liver regulated by glucokinase and in the muscle by hexokinase). Then it is further
converted into glucose-1-phosphate Uridine diphosphate glucose Glycogen.
This process also works the other way around. When energy is needed, glycogen can be
broken down into Glucose-1-phosphate Glucose-6-phosphate, which can enter the
glycolysis pathway.
Glucose-6-phosphate can also be converted in the liver to glucose, this happens by the
enzyme glucose-6-phosphatase. In the muscle this enzyme is missing. Most of the energy is
needed in the muscle so you don’t want glucose to leave it. Whereas in the liver, this is
,needed because it is stored in the liver in the form of glycogen and when you need the
energy, glycogen will be converted back into glucose. Glucose will leave the liver and it will
be transported to the muscle where it is needed.
Glycogen
There are two different glycogen pools in the muscle, and this adds a new dimension to our
understanding of glycogen synthesis and utilization. These two pools are proglycogen and
macroglycogen. Research has identified a primer for glycogen synthesis (the protein
glycogenin). This acts as both the core of the glycogen molecule as well as the enzyme that
stimulates self-glycosylation. The initial accumulation of glucose units to glycogenin forms a
glycogen type that we know as proglycogen, and is of a relatively small size. The storage of
proglycogen is the most prominent in the first phase of recovery and it is sensitive to the
carbohydrate that you eat. During the second phase of glycogen recovery, glycogen storage
occurs mainly in the pool of macroglycogen. This is a glycogen molecule with a greater
amount of glucose to the glycogenin core. It is the increase in the macroglycogen pool that
appears for the glycogen supercompensation in the muscle.
, Background on fat
Tryglycerides are the lipids that are most well-known. These are three fatty acids with a
glycerol attached to it. This can be used for energy straight away or stored in the form of
triglycerides (in muscle or adipose tissue). When needed, it can be used in the muscle or
broken down from the adipose tissue (converted to glycerol backbone and three fatty acids)
and then it can be transported to the muscle and used.
Adipose tissue
Adipose tissue can be differentiated between visceral WAT ((White adipose tissue) can be
found around the organs) and subcutaneous WAT (superficial fat). You can also differentiate
adipose tissue depots in upper body (abdominal) fat and lower body (gluteo-femoral) fat.
There is also fat within and between muscles where we can differentiate in SAT
(subcutaneous fat, right under the skin), IMAT (intermuscular fat, in between two muscles),
IMF (intermyofibrillar fat, in between two muscle fibers) and IMCL (intramyocellular fat, fat
within muscle cell).
For triglyceride to be broken down in three fatty acids and glycerol it needs to be combined
with three water molecules (H goes to glycerol and OH goes to fatty acids)
The nomenclature of fatty acids
The n in the structure stands for the number of C atoms a fatty acid has. You can
differentiate between saturated and unsaturated fatty acids. The unsaturated can be further
divided into mono-unsaturated and poly-unsaturated.
In a cis- double bond, the hydrogen atoms are at the same site, and a trans-double bond
hydrogen atom are at the site against each other.
SUMMARY OF LECTURES
Pascal Wischhoff
,Substrate metabolism
There are three substrates, carbohydrates, proteins and lipids. Only carbohydrates and
lipids provide energy for the body. Protein is more used for protein synthesis and not as a
substrate.
Background on CHO
Carbohydrates can be found as saccharides. The
simplest form is a mono-saccharide (e.g. glucose,
fructose and galactose).
Di-saccharides are two mono-saccharides
together.
Poly-saccharide are more than two mono-
saccharides bound together.
Mono-saccharides lead to a quick spike of blood
sugar levels. This is mostly something that you
don’t want since you get energy very quickly and
then your blood sugar levels decrease again.
Poly-saccharides are digested in a slower way and
this leads to a slow absorption and a slow increase
of blood sugar level.
Digestion and absorption of poly-saccharides.
When they are eaten, they first need to be broken down into mono-saccharides. Then they
can be either used for energy in the muscle or it can be stored in the muscle or in the liver
until you need them at a later point.
When you eat something, it first needs to be broken down into Glucose, Fructose or
Galactose (depending on the kind of carbohydrate ingested). Then these mono-saccharides
can be either used for energy or they can be stored in the muscle or liver in the form of
glycogen. Whenever it is needed, glycogen can be converted back into glucose. The liver will
excrete the glucose, travelling to the muscle by the blood vessels where it will be used for
energy. Also, the glycogen in the muscle will be converted back to glucose, where it will be
used for energy directly.
The pathway at which glucose enters the muscle or the liver and how glucose is stored
into glycogen.
Glucose is taken up by Glut2 (glucose transporter) in the liver and Glut4 in the muscle, this is
insulin or contraction mediated. Then glucose will be converted into Glucose-6-phosphate
(in the liver regulated by glucokinase and in the muscle by hexokinase). Then it is further
converted into glucose-1-phosphate Uridine diphosphate glucose Glycogen.
This process also works the other way around. When energy is needed, glycogen can be
broken down into Glucose-1-phosphate Glucose-6-phosphate, which can enter the
glycolysis pathway.
Glucose-6-phosphate can also be converted in the liver to glucose, this happens by the
enzyme glucose-6-phosphatase. In the muscle this enzyme is missing. Most of the energy is
needed in the muscle so you don’t want glucose to leave it. Whereas in the liver, this is
,needed because it is stored in the liver in the form of glycogen and when you need the
energy, glycogen will be converted back into glucose. Glucose will leave the liver and it will
be transported to the muscle where it is needed.
Glycogen
There are two different glycogen pools in the muscle, and this adds a new dimension to our
understanding of glycogen synthesis and utilization. These two pools are proglycogen and
macroglycogen. Research has identified a primer for glycogen synthesis (the protein
glycogenin). This acts as both the core of the glycogen molecule as well as the enzyme that
stimulates self-glycosylation. The initial accumulation of glucose units to glycogenin forms a
glycogen type that we know as proglycogen, and is of a relatively small size. The storage of
proglycogen is the most prominent in the first phase of recovery and it is sensitive to the
carbohydrate that you eat. During the second phase of glycogen recovery, glycogen storage
occurs mainly in the pool of macroglycogen. This is a glycogen molecule with a greater
amount of glucose to the glycogenin core. It is the increase in the macroglycogen pool that
appears for the glycogen supercompensation in the muscle.
, Background on fat
Tryglycerides are the lipids that are most well-known. These are three fatty acids with a
glycerol attached to it. This can be used for energy straight away or stored in the form of
triglycerides (in muscle or adipose tissue). When needed, it can be used in the muscle or
broken down from the adipose tissue (converted to glycerol backbone and three fatty acids)
and then it can be transported to the muscle and used.
Adipose tissue
Adipose tissue can be differentiated between visceral WAT ((White adipose tissue) can be
found around the organs) and subcutaneous WAT (superficial fat). You can also differentiate
adipose tissue depots in upper body (abdominal) fat and lower body (gluteo-femoral) fat.
There is also fat within and between muscles where we can differentiate in SAT
(subcutaneous fat, right under the skin), IMAT (intermuscular fat, in between two muscles),
IMF (intermyofibrillar fat, in between two muscle fibers) and IMCL (intramyocellular fat, fat
within muscle cell).
For triglyceride to be broken down in three fatty acids and glycerol it needs to be combined
with three water molecules (H goes to glycerol and OH goes to fatty acids)
The nomenclature of fatty acids
The n in the structure stands for the number of C atoms a fatty acid has. You can
differentiate between saturated and unsaturated fatty acids. The unsaturated can be further
divided into mono-unsaturated and poly-unsaturated.
In a cis- double bond, the hydrogen atoms are at the same site, and a trans-double bond
hydrogen atom are at the site against each other.
