energy metabolism during endurance sports
As the energy comes from food into the body and the bike on the road?

The following information is culled from books and websites. I am neither a doctor nor a biologist - The following article is hence "with no guarantee of accuracy '... Thematically, the topic "from back to front" described - from the muscle contraction to the photosynthesis.
parts of the illustrations are courtesy of the publisher " trade and technology" from the book 'basic issues of food' (Cornelia A. Schlieper) removed.
1) mechanism of muscle contraction

The movement of the two molecules takes place in several phases - the so-called cross-bridge cycle. The 'head' of the myosin molecule jumps between contacts on the actin molecules (the illustration to the right comes from the English Wikipedia article ). This cycle can run 10-100 times per second (if enough ATP is available). The process is controlled by electrical charges, the nerve cells come in the form of calcium ions into the muscle cells.

muscle fibers consist of a variety of such actin / myosin molecules (plus 'passive' proteins such as eg. The giant titin molecule ), which are arranged in various forms. The smallest unit is called sarcomere.

Links:
- contractile mechanism ( we ) (the drawing is from the right side)
- introduction and animations of myosin / actin (L2 )
- " conversion of biochemical energy into mechanical work, publication of the Institute MaxPlank.
- schematic drawing of a muscle L2

2) energy metabolism
2.1) energy production in the cell -. Overview

The utilization of nutrients into energy in the cell is a three-step process. In the first stage, the initial products in a few "Basic fuel molecules" converted. The substance acetyl-CoA is one of the most important fuel - it is more or less the "hub" in the processing of carbohydrates, fats, and (some) proteins dar.



other publications.
- " The Muscular energy supply in the sport ," Dr. Moos
- " The energy metabolism ," Dr. Moos
2.2) carbohydrate metabolism

2.3.) fat metabolism

goes in several publications of the sports physician Dr. Moos one on the topic of fat metabolism during exercise. He criticized the possibility the myth of the 'heart rate zone is burned in the fat' or that 'fat burning begins only after 20 minutes'. The fat metabolism is always active, not only in the so-called 'fat burning zone', or only after some time. If you want to remove you just have to eat fewer calories than you consume ...:
- " fat burning in the sport, myth and truth "
- " Heart Rate: Is it the fat burning zone while exercising ?
2.4.) Protein metabolism

proteins are built on demand from free amino acids. Non-essential amino acids can be produced by the body. Essential amino acids however have to be supplied through food. From the free amino acids, the body new proteins by producing a copy of the pattern of RNA -section - a part of a DNA molecule - one part of the human genome encoded program of life. The free Amminosäuren store on to a mRNA molecule - which has previously been replaced as a zip of a DNA molecule. .
- " protein metabolism ," Dr. Moos
2.5) Multi-stage energy storage body
Some very interesting articles on energy supply can be found on the homepage of Dr. Moos - particularly appropriate is the publication ' Muscular energy supply during exercise '. Important for the following paragraphs is: the mechanisms to run always from each other, the anaerobic splitting of glucose does not hear abruptly when the aerobic cleavage begins. But with different exercise duration and intensity outweigh individual mechanisms.

As described above, transfer chemical energy from food constituents on ATP and in areas such as muscle contraction re-released. ATP itself is only in low concentration in the cell. ATP is and will be transferred from "memory drugs" restored. The energy extraction from the available ATP in muscle is sufficient for 1-2 seconds. Weightlifting use eg. primarily this energy source.
Level 2: CP (creatine phosphate)

Level 3: Anaerobic Degradation of glucose / pyruvate


Level 4: Aerobic degradation of glucose / pyruvate

Level 5: fat, protein
The fat and protein reserves in the body are usually sufficient to prevent the body about 40 days to supply energy. If you eat nothing for 40 days, a person weighing 75kg is building about 14-15kg fat and protein to sustain life.
2.6.) Hormones
Hormones are chemical messengers that communicate through the various body parts together. Hormones are usually constructed from Amminosäuren. Various glands produce hormones, plays a central role in the pituitary . Hormones are primarily via the blood circulation transported. The contact with receptors in organs then lead to reactions. An important hormone in metabolism is insulin . When insulin is released to try organs with insulin receptors (especially the liver), glucose can be seen in the blood and convert it into glycogen, the storage material. The opposite of insulin - glucagon - causes the other hand, increased degradation of glycogen to glucose and release into the blood.
3) digestion
The digestive system converts food into simpler, usable materials for the body.
3.1.) Enzymes
By enzymes are mainly in the mouth, Stomach and small intestine 'great' nutrient molecules into smaller parts divided. The main work take over enzymes from the pancreas (pancreas) generates, in the small intestine to the food act. Through the intestinal wall, the split-nutrient components enter the blood and lymphatic circulation and be transported to the cells. There they are recycled, stored or converted. Non-recyclable nutrients and waste products (eg CO2) are eliminated.
3.2) digestion of carbohydrates
The enzyme amylase -. A component of saliva - separates the mouth and stomach long-chain carbohydrates on. In the duodenum contribute their production of the pancreatic enzymes amylase and glucosidase - the long carbohydrate molecules are further reduced. In the small intestinal wall, including the conversion is completed. Reach the blood stream glucose, galactose and fructose.
3.3.) Digestion of fats
Also in fats, the task of digestion, the captured molecules to break down into simple components. Fat is digested mainly in the small intestine by pancreatic enzymes (lipases) and bile into monoglycerides, glycerol and fatty acids. About the small intestine wall, the fat components in the blood and lymph circulation are included.
3.4.) Digestion of proteins
take over the breakdown of proteins, the enzymes of the group peptidases (pepsin), which act primarily in the stomach. In the small intestine other enzymes of the pancreas and to cleave the proteins into simple amino acids, which enter through the intestinal wall into the blood.
4 .) Elements of food
4.1.) carbohydrates

monosaccharides (simple sugars)


disaccharides (double sugars)

oligosaccharides (Complex sugars) and polysaccharides (multiple sugars)

play in the sports nutrition dextrin or maltodextrin a role. This refers to a mixture of shorter degradation products of starch or glycogen, consisting of approximately 4 to 40 glucose molecules. Energy gels often contain maltodextrin. By mixing and shorter long-chain molecules, the energy absorption into the bloodstream over a longer period is extended.
4.2.) fats, fatty acids

fatty acids are 'saturated "means, if each carbon molecule is connected to the carbon chain with two hydrogen molecules.

an important fat group in the human body, the so-called mono-, di-and triglycerides - compounds of glycerine - C3H5 (OH) 3 - 1, 2 or 3 fatty acids. triglycerides are stored nutrients in the body. In this form, lies a body of excess energy for lean times in fat cells.
4.3.) proteins / protein, amino acids

proteins are made up of chains of amino acids . Amino acids are a class of organic chemical compounds, with two distinctive components ( COOH and NH2 ). Amino acids, the building blocks of proteins are called "proteinogenic", the many other "non-proteinogenic". In humans, there are 21 amino acids, 9 of which the body can not produce themselves - they are referred to as " esenzielle amino acids.

On food proteins, for example, when eating meat, fish, eggs, dairy products and nuts are included. During digestion they are broken down into amino acids that are transported by the blood into the cells. In the cells they will then use the genetic information of DNA reassembly of matching proteins. The part of the cell where proteins are built up, is called ribosome. .
4.4) Other nutrients
There are many other important nutrients, without which it would not survive - for example water, salts , electrolytes, vitamins , trace elements , dietary fiber, phytochemicals , minerals . Since I am here primarily concerned with energy metabolism, I have not dealt with these materials.
Links:
- " drinking in sports ," Dr. Moos
- " The daily water demand ," Dr. Moos
4.5), energy-, calorie
calorie
in the field of nutrition. common unit calorie (cal or kcal) is actually outdated. Valid the SI unit joule (or Was, Nm). 1 cal is the amount of energy to 1g water to heat up 1K. 1 joule is the energy to make 1 watt for 1 second to 1 meter wide and apply a force of 1 Newton. Approximately applies: 1 cal = 4.2 J.
condensing
The physiological calorific value is the amount of energy the body can gain from a given quantity of food. Normally the value is specified in kJ/100g or kJ/100ml. Order pasta: about 1500kJ/350kcal per 100g.
BMR
As ' BMR ' refers to the amount of energy required for a healthy body at 28 ° C on the vital functions to maintain. The basal metabolic rate is dependent on many factors and should therefore be seen as a benchmark: about 90kJ/kg or 21kcal/kg in women and about 100kJ/kg or 24kcal/kg in men - women are working ever more efficiently than men.
Links:
- " sensible diet," Dr. Moos
- " diet and nutritional supplements in sport ," Dr. Moos
5) photosynthesis
And how does the energy in the oatmeal? It is basically the light of the sun that drives us. The plants convert light energy through photosynthesis, the CO2 and water into O2 and glucose.

removal efficiency is surprisingly low - only 0.8% of the incident light energy is converted into chemical energy - And of them produce large amounts of organic material - per hectare hardwood forest occur, for example, about 12 tons per year, total on Earth about 150 billion tons per year.

6 ) sources
Wikipedia
the world's most brilliant website

Cornelia Schlieper
publishing trade and technology
source. Eg. publishing trade and technology
A book that I like very much. The clear illustrations make it possible for lay people to go into the topics. The book also increases a little further in-depth than eg. the book by Peter Konopka, but remains practical enough that even the more complicated sections should be read with pleasure.

Horst de Marees
Publisher Strauss
sources, for example. Amazon
A book for many long nights. Concentrated sports theory to approximately 800 pages. The issues extend beyond nutrition and metabolism. It is for example. Chapter on performance diagnostics, respiratory, cardiovascular, sports in the level or about diving and much more.

Geiss KR, M. Hamm
rororo Publisher
sources, for example. Amazon
also a great introduction to the basics of nutrition, metabolism and physiology. The focus is on theory.

Antje Galuschka
S. Hirzel Verlag
A great, in theory, more focused book that is free to paperc.de available online. The theme of the metabolism also lead for example. on topics such as genetic engineering and the immune system.

Peter Konopka
BLV Verlag
sources, for example. Amazon
also a great book. The focus is less on the deep theory as to the application in various sports (endurance, strength, endurance sports, etc.)
Optimized Endurance Training

publisher Meyer & Meyer
sources: eg . Amazon
The food theme is 'wide-treated side show'. The book offers but in addition to nutrition and metabolism an attractive entry into adjacent areas such as Trainingsplaung and regeneration.
Challenge Race Across America
Michael Nehls (Finisher 2008), Uwe Geissler

sources, for example Homepage Michael Nehls (signed edition available), Amazon
The book I have mentioned several times in postings. There is also a detailed chapter on nutrition in ultra-sports. When Raceacross America I find the importance proper nutrition remarkable. The amount of calories that can accommodate the digestive system determines the performance of drivers. Through much of the route can only bring the power to the road you again also can hold. For the vast majority of sports, bring the power from before (in glycogen or fat) in the body of stored energy.
other interesting websites
- Dr. Moos , very interesting publications on the subject of nutrition and metabolism during exercise.
- Science of Sport , detailed blog by Ross Tucker and Jonathan Tucker (two sports-PhDs), often with endurance sports themes, such as nutrition in the Tour de France .
- Google Scholar provides many scientific publications of sports-Unis
- lectures at the University of Tübingen , hundreds of hours of video recordings of lectures (each 45 min), for example.
- Biochemistry 1 (15x), including hour 9 (TCA cycle)
- Biochemistry 2 (35x), etc. Hour 1 (proteins), from hour 22 (carbohydrate metabolism)
- Biochemistry 3 (45x), including Hour 1 (carbohydrate metabolism)
- Biochemistry 4 (35x), among other things hour 34 (muscles)
- Cell Biology 1 (20x), among other things hour 9 (mitochondria)
- Plant Physiology (41x), among other things. hour 10 (photosynthesis)
- Lectures4you : collection of links to freely available scripts / videos of lectures of various universities
- online vorlesungen.de : Links above, links to many prestigious universities such as eg. Berkley , eth Zurich
7) Conclusion
With every page I read about these topics, I find it impressive how good and stable, the body - these highly complex biochemical factory - so many years of life (most people) is working. It's amazing how interlock mechanisms and regulated. It is amazing how much energy the sun releases. It's an incredible gift to be able to live in such a world.