Introduction 
A sports performance includes several parameters: technical, experience, mental management, equipment, preparation ... without forgetting physical abilities ... 
A loss of 2% of the athletes' weight (mainly due to water loss) during exercise lowers physical abilities of by 20%!

Interest in hydration is an attempt to answer two questions:
Why the loss of water leads to loss physical abilities?
How to hydrate during endurance effort?

Why drink? 
Beware of preconceptions; often we hear: 
"We have to drink because you sweat, it cools down the body." 
This is true but not only ... 
The water actually helps maintain ideal body temperature (evaporation and sweating) ... 
But it is also essential for muscular work (enzymes operation and minerals intake (sodium, potassium ...) 
Therefore the water provides a good energy transmission in particular through blood plasma. 
Do not forget that without water, our body can not store energy. 
The food of the muscle is partly glycogen. 
To store 1 gram of glycogen, it takes 3 grams of water. 

Bridging loss micronutrient:
From the water that we lose during sporting activity (sweat) escapes a very large amount of essential micronutrients for the balance of the osmolarity. 
We need to replace the micronutrients' loss  in a very short time  to maintain effort in good condition and to ensure post-exercise optimal recovery. 

The body is well done, in a "normal" moderate sport situation to initiate a process of cooling, a compensatory mechanism of the blood volume starts  and the water is then supplied mainly by  water of our small cell. 

Making very large amount of sweat is initiating a blood volume decrease: 
So when stress becomes severe or continues in  long term, this mechanism is or too slow to get organized or  is not enough. 
In this case water is mostly  supplied  by the plasma. 
It has therefore to rebalance the plasma volume with a beverage having the same concentration (or osmolality)of  the blood. 
This drink will have the advantage of not creating an imbalance between the stomach (or intestine) and blood capillaries ... 

Follow a balance in  water / plasma osmolarity:
It explains for the very destructive competition in term of micronutrient (heavy sweat)that you should select beverages that meet osmosis phenomena. 

And this is where the relevance of such beverages containing glucose polymers (Glucose long chain) commonly called "maltodextrin" ... 

Indeed maltodextrin have an osmolarity just below the plasma:
However beverages with dextrose or glucose are easy to avoid during these endurance high micronutrient loss efforts: they are difficult to assimilate by organizing With  very different way from that of plasma osmolarity. 

Plain water?
If you are looking to optimize hydration during exercise, plain water is also to be avoided because it can't alone achieve the necessary plasma volume equilibration. 
With flat water (by definition "diluted" ...) creates an imbalance with the blood which is  increasingly concentrated during effort ... 
on another hand, plain water alone leaves the stomach more slowly than water mixed with maltodextrin. More the waiting time is long in the stomach (gastric emptying) ... Less organs and blood plasma are fast "fed"...
To illustrate my point, it's a bit like a tea bag in water, you still have some time before the water and the bag have the same level of concentration.
That is why drinking plain water supplemented with energy bars will not have the same level of optimization, of hydration, than an isotonic drink with identical blood Plamsa osmolarity. 
Indeed there will be a significant time lag between when the water will be "potentially" used by the blood, andd the blood + nutrients from the bar to be  used ... the impact will be lowered with energy gels taken at the same time as still water. 


Mineral:
First potassium, phosphorus and magnesium are normally given by food ... Remenber that even powerful drink as it can be   DO NOT intended to replace solid food , before exercise or during exercise ... if is greater than 2 hours.
Having said that  all spring water or mineral is itself provided naturally in minerals. 
Each mineral water to its specificity, read the labels and focus on highly mineralized waters. 

vitamins:
Glucose arriving  in our cells needs vitamin C to transform it into energy molecule ... But as part of a balanced intake before exercise vitamin power is unnecessary during exercise. Beyond 4h effort we can consider supplementation but never in  orange juice (too acid!). 

The water circuit in the body:
If drinking a glass of water is a simple gesture, mechanisms competing to create the sensation of thirst, have dictated the decision is the result of complex interactions, and ingestion will trigger with low biological response of a complex control system. Just drunk,  the water arrives in the intestine; rapidly absorbed, then it is properly routed to the kidney,  where two million nephrons begin to work to dilute, concentrate, then excrete what in this supply of water came suddenly increasing the water storage in excess . The amount of water retained by the body is constant because the kidney is the main responsible for the management and monitoring this stock. However, "sandwiched" within this stability, continuous fluctuations occur. The water distribution in the body is indeed in perpetual motion, and osmotic forces are the main factors governing exchanges between the various compartments. Sodium, especially extracellular location, and potassium, electively concentrated in intracellular spaces, play an important role. As to the water itself, it may be free or in  bound form for the latter ion excretion in the kidney. 
In the body, there is a biological equilibrium, for a person in good health, living in a temperate climate, kidneys easy can maintain balance. However, the mechanisms may, in certain circumstances, pathological or not, find themselves overwhelmed or caught out. Thus in a heart patient or in a cirrhotic subject to strict sodium diet (without sodium), excessive water absorption can result in poisoning, sodium located in insufficient quantities to remove excess water . 

What to drink:
Takin the risk repeating  myself, the goal is to make a drink that is as close as possible to the characteristics of body fluids. 

The basis of preparation: water 
mineral water or water from home? 
First we must bear in mind that the principle of mineral waters supposed trade heavily loaded with minerals is primarily a sales pitch. 
Yes yes ... you should know that the minerals in water are inorganic. They have a very low absorption level  and are therefore very relative useful to the metabolism. 

I would like to point this : it is the organic minerals that are most appropriate for the body : ie those fruits and vegetables! 

In an effort to less than 3 hours in winter weather with little sweating, excessive mineralization of the water should be avoided instead to avoid overloading the kidney work. 
However, if heat and / or very long session (with significant losses in minerals)  happen, a water "Hépart" or "contrex" is interesting. 
It is also this type of water I recommend for indoor cardio sessions (type home trainer, elliptical trainer) because: 
heavy sweating = loss of minerals! However, I would  nuance my comments ... 
yes after exercise 1 glass of Vichy water, or better yet Badoit Saint Yorre, will strengthen the full mineral ... even if it will be a priority by taking fruits and vegetables after effort (soup, applesauce). 
These sparkling water, rich in bicarbonates also help to remove lactate ... so  fatigue feeling decrease. 

Sugar intake: 
Do we need  to recall that the muscle uses glucose as an essential fuel (taken directly from the diet and the digestive tract and blood plasma or already stored by the body in the muscle itself and the liver: glycogen reserve). 
This glycogen is limited to 90 minutes (maximum) effort ... beyond, the body will have to find  energy elsewhere: 
in fats or, if  very clever athlete with  immediate arrival of new glucose molecules! 
But here to use glucose, a chemical reaction is taking place ... it combines enzymes and oxygen to water molecules! 
The process of using glucose in turn produce the cells of the water molecules and carbon dioxide (Kreps cycle). 
(in a situation of very intense effort, reaction occurs without oxygen, "anaerobic")
So ... for 90 minutes at the most (if the subject is at very good level) water body is sufficient for purposes of utilization of glucose and produce energy. 
Then if the water supply has not been done ... well almost everything stops! 
And is often followed by the famous pump stroke  associated with the sensation of a terrible thirst! 
Then we hear "I'm in hypo"... We should just say "I'm dry"! 
Because of blood glucose without water molecule in the cells is a bit like having a diesel engine with the fuel without direct access to the engine tank! 
When we go beyond the famous 60 to 90 minutes you are in this situation of cellular dehydration! 
The body then shouts "to the rescue!" 
Sugar yes, but ... 
If the drink is very sweet the time of ingestion is increased and digestive problems may occur. If, however, it has little or no sugar, much of the liquid will not be absorbed and will be removed in the urine. 
The rider will be weighed down, his breathing may be impaired and to still lose a little more time, he will stop frequently to urinate! 
A concentration of 60 grams per liter avoids these drawbacks while providing some of the sugar necessary to muscular work. 

Minerals: 
About 200 mg per liter of sodium and potassium. 
there are many minerals that allow entry of water in our small cell, but these are mainly sodium and potassium which will play this role.

Table salt: with caution ... 
200 mg per liter is still low and therefore totally unnecessary to build a very strong salt water ... unless you go to the Sand Marathon! 

The intake should be moderate during exercise and excess may even been harmful by the oversubscription of the renal system. 
Warning ingesting salt tablets, usually highly concentrated, can increase digestive secretions and hence be responsible for digestive disorders. 
In my point of view, they should only be used in cases of severe dehydration ... so by definition when the athlete is obviously very wrong with has to stop ...! In fact most of the time tablet increases the work of the kidneys; we are very far from a use to optimize hydration during the event! 
That said, my words ... I would say salt tablets are highly recommended for those who do not have kidney problems during very specific events such as the marathon of the sands where in ultra long distance cycling or running. 
Anyway a drink with a concentration of salt in the order of 1 g - 1.5 g / liter widely enough, especially since the risk usually is not a lack of salt since the sweat is more water than a loss of salt. Sweat is hyponatremia compared to plasma. 
1.2 g of salt per liter is equivalent to the salt concentration in the liquid intra / inter cell. 
Do not forget the salt (NaCl for short) was first function to participate in the absorption of carbohydrates by our dear little cells to transform it into energy (ATP ... again for short!) 

 Baking soda:
Some nutritionist advocates taking baking soda, makes the assumption that it s increasing the capacity of tissues to buffer the acids produced by the effort, it could increase the resistance to muscle fatigue; which acidity is responsible. 

Unfortunately, to date, no study, no lab does not support this thought ... so it does not seem taking baking soda well and on top of this digestive disorders has been widely recognized! 

tea:
Green tea is better than black tea ... yes do not forget that black tea has undergone fermentation ... 
Tea brings water therefore in principle it hydrates. But each tea has its own characteristic based on the theory of yin and yang. 
ying: cold, quiet, girl, water 
yang: warm, light, motion ... 
red tea, black = yang 
green, white tea = ying 
Yellow = neutral 

dosage 
Several parameters must be taken into account for the determination of the concentration of the drink: 
The humidity (greatly reduce the concentration in stormy weather) 
External heat (eg, more hotter the more you reduce doses) 
The exercise duration (longer it will take more concentration dextrose will be reduced to benefit to maltodextrin)
The intensity of effort (with a violent effort and short enough you can increase the amount of dextrose / glucose) 
The nature of ingested carbohydrates (if drinking heavily dosed maltodextrin, lower concentration) 
The temperature of the solution (more liquid will be cold higher will be concentration) 
The sodium content of the solution (it is more significant the higher the concentration is low) 
The interval between ingestion phases ( lower if close together)
The condition of the stomach (empty or full) 
In short it is to fill a stomach ... but it's even better to make sure if we will then be able to digest it! 


How to drink?
It is important to drink in the first fifteen minutes of effort. 
Remember that thirst is felt when dehydration is well underway! 
Taking drinks benefit from being common. It is recommended to drink small amounts frequently rather than a large amount of time to time. 
The body is not able to absorb more temperate atmosphere in about 800ml (1 liter to 1.5 liters per hour maximum). 
Needless to reach the stage where excess water drunk is going directly to urine. 

Repeated every 7 minutes sip is a fairly reliable indication 
Fragmentation reduces fluid intake difficulty and increases digestion absorption liquid. 


Beware of preconceptions ...

Over hydration: 
Remember the risk of over hydration bis causing hyponatremia (low sodium levels in the blood). Each year the over hydration causes the death of marathoners ... 
It's been a long time since we no longer advise runners to drink in large quantities. 
Studies published in recent years have shown how this recommendation could be dangerous. 
A study by the expert (Tim Noakes) on nearly 500 runners who completed the Boston Marathon in 2002 showed that 13% of runners had hyponatremia at the end of the race. Hyponatremia is the drop in sodium levels in the blood (<135 mmol / l). It may come from leakage of salt in the body (for sweating ...), but also by a large intake of water. When lower, sodium levels reached critical levels, it can have serious consequences on the body (brain swelling ...). 


Urinate a sign of dehydration?
Here and there i see the idea of urinating could be a sign of dehydration! 
This is not the urine itself  the sign of a state of dehydration .. but its color ... which is the manifestation of the density level of electrolytes waste removed ... 
Do i need to repeat that hydration means the supply of water by mouth (or intravenously) ... to fight against dehydration!!;)
The production of urine is the main route for the release of excess water ... but it is also the escape route of electrolytes (sodium, potassium in particular) 
Gradually, as the loss of water through sweating increases during exercise, the body will protect itself and therefore try at all costs to maintain a minimum capital of water and keep the little water that remains ..  by slowing urine ... 

The direct consequence of this mechanism: 
Waste disposal (electrolytes for short) will become very weak! 
Dehydration is always characterized by the absence of urine or dark urine, and in small quantities. 
So almost systematically one who does not urine has not drunk enough!


Hypoglycemia does not have a direct link with water supplies 

The classic hypoglycemia 

Hypoglycemia is  occurring after 2 hours of effort ... is NEVER linked to a  contribution of sugar! 

Shortly except specific diseases (endocrine) and very rare one, there are three sources of hypoglycemia: 

A lack of glucose 
This is the case for the vast majority of athletes
Reminder:
Glucose enters our cells in two ways: 
A. from food and the digestive tract via the blood plasma 
B. from liver using liver glycogen and again transported by the plasma 

An excess of insulin 
what happens in the reaction hypo I explained below 

An activation of the production of ketone bodies default 
during an  empty stomach  period severe and long, due to the lack of availability of use of essential fatty acid

Reactive hypoglycemia 
This is the beginning of hypoglycemia effort called reaction that NEVER occurs  after a long effort! 
When an athlete takes sugar just before strenuous exercise (eg a very sweet energy bar on the start line) general energy shock is created between the 20th and 30th minutes.

The sport often with empty stomach for 3 hours (the famous meal 3 hours before exercise concept that does not really coast when the power is suitable for efficient and rapid gastric emptying) is left with a rapid influx of glucose; glucose is increasing, the body will respond by secreting large amounts of insulin. 

And it is this insulin will begin the process of hypoglycemia ... 
hence the name of "hypo reaction" ...

Text translated and adapted from Alain Roche.

Watch more HIIT free Fitness video in this category.
WARNING:
this video is a workout session for abs level 2 with a stepper no beginner there , or watch back pain ! 

Lactic acid is often used as a scapegoat!!
Who has not already read the abominable lactic acid is the ruthless explanation for fatigue the next day or two days later.
The problem is that the brave beast is eliminated very quickly in about ten minutes after exercise! 
Acidosis is primarily a chemical problem H+ ion (proton) 
It is important not to confuse lactic acid and acidosis, acidosis is mainly due to the large accumulation of ion H+ ... not lactate. 
It is this accumulation of H + ions (protons) that in the vast majority of cases causes these aches and nice wooden legs the next day of racing. 
It is therefore not lactate concentration that will change the balance called "acid-base" but the concentration of H + ions.
Those wishing to know more can read the works of Cailler and his remarkable lactic acid work on:
"The proton: exercise and tired" (Science and Sports) Cailler J. et al, 1996. 
There are many articles on the internet that talk about the impact of H+ after an intense effort. 

And if lactic acid was the benefits?

The pure session MAS which cause high production of lactic acid has an interesting positive side for this very production of lactic acid. 

When the levels of lactic acid rises, secretion of growth hormone increases! 

This peak lactic acid that occurs at the end of the split is somehow passing control to the body to secrete growth hormone (GH), hormone that starts to turn the regeneration process and muscle development. 
Who wants to strengthen that capacity, pretty cool, right? 

Lactic acid and legs hard ... careful  to popular belief ... acid does not explain everything! 

Warning, lactic acid does not explain itself legs burning  after working high% MAS! 
Why? 

In advance thousand apologies for what follows, even while trying to simplify it may be a bit of "headache"..
When muscles receive the electrical signal from the brain to activate, its muscle fibers become loaded with sodium and release potassium. 
Naturally over splits sodium accumulates in the fibers ... while the potassium level decreases at high speed. 

Luckily our organization has in the fibers of a kind of pump that can compensate for these changes by activating the exchange sodium / potassium between the inside and the outside of the fibers. 
But then the action of the pump has its limits when it can't  no longer do the job it will be the red alarm with hard legs and other signs of muscle fatigue ... 

Am I out of balance in terms of acidosis?

It is essential to look at the problematic identification symptoms of acid-base loss balance:
These are: 
_ Dry skin (after shaving for men).
_ Dull hair / falling / brittle (rather female signs). 
_ Nails brittle / split / striped.
_ Nervousness, abnormal cold extremities despite not extreme weather conditions
_ Muscle pain or abnormal joint under training load  unmodified habits
_ Overall lack of regular energy.
_ Ability to recover with values ​​of heart rate variability (HRV in particular) at half.
_ Unfamiliar mood irritability.
 
 
Why acidosis disrupts the functioning of the body? 

Acidosis is putting significant loss of minerals: calcium (bone) and magnesium (especially nervous system). 
These are highly mobilized and thus lost to neutralize (buffer) acids. 
The various organs and tissues that provide these minerals buffers will therefore be irreparably demineralized.
This demineralization will decrease the immune system. 
It will also seriously disrupt the work of enzymes that require a specific pH to work properly ... and so raise a little acid load. 
Snakes' story biting its tail to resume! 
 
Operating on  "three legs" of enzymes will strongly disturb the production of proteins and other hormones. 

Acidity will promote tissue inflammation. 

The massive use of mineral salts to neutralize (buffer) acids will cause a large crystals deposit  ... 
Yep ... one acid  linked to a mineral salt alkalizing  becomes, to be short, a salt (neutral this time) and water ... 
But salt is not easily removed ... and suddenly put  a" little mess" remaining in the body. 
This "little mess" has the  bad reputation of causing tendonitis and shin splints other ... not very cool ... 
 
Reduce acidosis, it's possible!

Avoid acidic foods 
Our body hates excesses of all backgrounds ... and it needs to function properly to maintain a certain constant acidity. As indicator if blood acidity goes  over 7.5, discomfort is in sight ... and if the counter panics it's death after ... more something is acid, more  it contains  H+ ion ... not cool in terms of what has been stated above! 

Alkalizing foods highly recommended:
- All colored vegetables (except tomatoes) 
- Vegetable juice (beetroot, carrots in particular) 
- Sweet potatoes, chestnuts, potatoes 
- Bananas 
- Dried fruit (except apricots) 
- Sprouts
- Algae (spirulina for example) 
 
Acidic foods to avoid: 
- Acid fruits (plums, apricots, unripe fruits, rhubarb, pure citrus juice without pulp is rather to avoid except  -lemon juice will remain interesting) 
- Acid vegetables: spinach, tomatoes, cauliflower, sorrel,, watercress, asparagus.
- Excess dairy products: yogurt, curd, cottage cheese, small Swiss moderation 
- Vinegar, white wine is preferred tamarisk 
 
With Nuance ... anyway! 
It would be a bit simplistic, even ridiculous to only eat basic food (this would require simply to stop all intake of carbohydrates and lprotéines! ...). 
We just have to stay a bit careful to keep a balance on meal acidifying and alkalizing foods. 

Three principles of elimination

Elimination through respiration for volatile acids:
The body through the blood carries the H+ ions in combination with bicarbonate (carbonic acid) (H2CO3). 
This acid will be removed from the lungs, under water and carbon dioxide. 
That's why the next session after a race will in particular aims to increase the breathing rate to help eliminate some of our H+ volatile ions. 
 
Elimination of non-volatile acids by kidneys 
"Fishing" in primitive urine  the sodium (Na +), by exchanging it with H + ions. However, this system depends upon the needs of sodium. 
For more complex acids (particularly ammonium NH4 +, part of ammonia NH3 and H +), they are eliminated by kidneys. 
Kidney recovers bicarbonates to be used in the neutralization of acid and recovers sodium to exchange it with the famous H + ions. 
In alkalosis (rare) cases, kidney no longer retrieves bicarbonates in primary urine, and thus helps to reduce alkalosis. 
  
Elimination by glands (sweat) skin
The H + ions do not explain everything! 

But beware you still have to remain in a subtle approach because it's a very clever one ) that could  state fatigue has only one origin ... it is indeed often due to various causes other than strictly metabolic factors ...


Text translated and adapted from Alain Roche.

Jeff Galloway one of the best experts on the topic of recovering long-distance runners demonstrated by a sharp recovery complete analysis of a marathon by an elite athlete is 30 days. 
It is indeed time to prolonged presence in the body of substances characteristic of intense physical activity such enzyme CPK (Creatine phosphokinase). 
Apart from this lab evidence of course that stocks of muscle and liver glycogen stores are replenished much faster if the diet is strict. 

The persistence of CPK several days after exercise is directly related to the severity of the effort and therefore the importance of micro-lesions due to this effort. 

In fact after this effort the body will be able to tap into these reserves, and reaction will be triggered from creatine phosphate which in particular in a first plane to reconstruct the adenosine triphosphate (energy reserve). 
This is the catalysis of the reaction [adenosine triphosphate + adenosine diphosphate + creatine phosphate creatine ]. 

So watch alerts JEFF GALLOWAY are related to the practice of ultra long distance running or trail that are very traumatic practices for muscles, tendons ... I do not even speak about joints ... 
It was after this type of event that we still find signs CPK present in 2-3 weeks. 
Tthe bike should still limit the damage a little .

It even happens in extreme cases of view of clinical symptoms of finischer ultra "no limit" identical to those buried earthquakes or road accident due to muscle crushing hard triggers a very important appearance CPK. 
This is called "crush syndrome" and in the case of muscle necrosis, elevated creatine phosphokinase which is the single most "striking" is not linear. Sometimes there is severe necrosis when a rebound of CPK. 

In terms of biochemical my knowledge (all on so certainly incomplete) there are three major markers of the destruction of our small muscle cells during exercise extreme: 

The rise of LDH (these large animals are also called lactic dehydrogenase). 
The increase of the myoglobin. 
And of course that of CPK. 

And exactly what is the CPK that will put more time to return to normalization. 
Pathologically one of the symptoms of the disease called "abnormal mitochondrial beta oxidation" is just a very high rate of cpk associated with severe cramps ... 


That's one reason why I say and repeat that it is not reasonable to continue an effort from cramps cramps on each cramp is synonymous with a lesion more or less ... and a rise CPK. 

That is why a minimum of common sense should allow each other to make an objective opinion on the credibility of  scheduling several competitions each  3 to 5 hours of effort ... with any drop of performance. 

Text translated and adapted from Alain Roche.

Sports training is built according a balance between training time (effort) and recovery time active or total rest).
Workout plan is to attack the body that will disrupt his balance. 
The interest of the training is to trigger a recovery phase that will encourage the body to regenerate ending up at "equilibrium" with a level higher than before"agression".
Overtraining is the result of an imbalance between training time (effort) and recovery time active or total rest.
It can affect athletes at all levels and occur stealthily without athlete or physical trainer noticing it and therefore of interest to all sports doctors. 
It often has multiple factors for overtraining: these includes multifactorial life "outside workouts" including work stress, family. Complex pathophysiology of overtraining syndrome is essential to know, to understand the "tracks" that led to propose a particular biological assessment. 
 
Be warned however not to point too quickly tiredness which can be corrected after a week of substantial rest regime and  overtraining as a chronic fatigue,  it does not evaporate as easily after overtraining unfortunately. 
Overtraining is actually basically a manifestation of an imbalance in energy, shortly the individual is placed in a situation characterized by an energy greater than its banking. 
So that, "in fine" overtraining is not only a physical penetration, as it occurs even mentally! 
 
3 fatigue states: awareness careful not to "fall" into a overtraining spiral 

Every sportsman knows after a workout a normal and a good sign of fatigue. 

This fatigue may be transitional and only observable in the next day or 48 hours maximum after exercise .

It may be more pronounced, it is called "the overreaching",  it's observed for example after a block of 3 to 4 days of heavy training load), if the rest is immediately initiated with a recovery period including  very moderate sessions, 1 to 2 weeks will sometimes remove the overflow. 
If the alarm phase of "overeaching" signal is not "heard" then go to the state of overtraining. In this case, the return to normal will require at minimum 1 to 2 months to see a lot more in some cases. 
 

The different type of fatigue 

When the mind and the will are not doing everything! 
This is our nervous system, the unconscious part of the brain, completely independent of our voluntary control, which manages our recovery and management of our tiredness ... 
It is this nervous system that controls especially the cardiovascular and respiratory functions. 
If the system is not at the top ... all commands will suffer the consequences.
The autonomic nervous system is divided into two branches called: parasympathetic and  sympathetic. 
 
The parasympathetic nervous system
It is the "automatic" control of our brain used for rest with effect of a decrease in heart rate 
Called "calming" it lowers HR. It is related to the ventilation and respiratory rate. 
 (very simplified summary) 

The sympathetic nervous system
This is the brain command to bring energy on days when the body made ​​an effort or if it faces a  high stress. The role of the sympathetic nervous system is to put the body on alert to accelerate the heart 
Called "stimulant" because it energizes, activates the degradation of fuel for the muscles (substrates) 
(very simplified summary) 

typologies fatigue

Fatigue A: collapse of two systems 
Fatigue B: a tone too high (hypertension) in sympathetic activity 
Fatigue C: a total collapse of the sympathetic activation 
Fatigue D: too high a tone of parasympathetic activity (the most rare but most severe fatigue) 

Symptoms of overtraining

Please note all of these symptoms do not appear, which complicates diagnosis, there is no single clinical sign, both subjective and objective, overtraining, but a cluster of symptoms that will make the diagnosis. 

_ bad result and feeling tired 
_ restless sleep, difficulty to fall asleep, nocturnal awakenings hypersomnia or vice versa. 
_ decreased appetite
_ muscular symptoms of legs hard, sometimes unusual cramps 
_ digestive disorders. 
_ An infectious context is often found in the 6 months before the state of fatigue (eg output mononucleosis) 
_ weight change: it can be positive or negative and vary from 3 to 5 kg. 
_ nutritional errors: if the hydratation level is good, very often a quick survey shows clearly insufficient calorie intake, in particular for sugar with a low glycemic index (starches) and proteins. 
 _At rest, the heart rate can be reduced markedly (the sympathetic activation at half mast) or severely increased 
_A stress pulsations quickly shows and crashes often at the threshold 1 (80-85% HR max) 
_legs quickly become hard without feeling pushing (in stress test, 2 mmol lactate threshold is often exceeded long before the arrival of stage 1) ventilatory submaximal are then higher and the maximum lactate generally lowered. The recovery criteria are generally much worse. 
 
What to do in case of suspicion of overtraining 

Physical examination by a sports doctor for: 
Look for any signs of a blood disease or tumor (lymph nodes inspect, inspection of the conjunctiva, skin. 
Search on cardiopulmonary plane abnormal blood pressure measured in the supine and standing position, abnormal electrocardiogram, especially if you have previous examinations. 
 
The stress test (with evaluation lactate): 
Search for a modification of "abnormal" heart rate, elevation of a possible ventilatory parameters (tidal volume and respiratory rate) 
Identify whether or not an increase in submaximal lactatémies. 
Identify whether sagging lactic and ventilatory thresholds 
 
the biological assessment 
Help to  eliminate a viral infectious disease and / or bacterial 
allow immune balance, hormonal and enzymatic. (CPK) 

the nutritional status 

seek a deficiency in hydration, rations of protein, carbohydrates, iron, especially of animal origin, 
to specify the type of power supply during exercise. 

So what if it is really there? 

No miracle recipe:
a first step of complete rest (2 to 4 weeks) 
a second step where we will introduce some short aerobic session walking, bike pedaling very flexible (2 weeks) 
a third step where we will introduce in the aerobic sessions short sprints to wake up systems..

Text translated and adapted from Alain Roche.