Exercise causes fatigue?
367256
You might not be eating the right foods.
27340
You may be favoring one hip and leg over the other. Hard floors also cause the back to fatigue more quickly. Try a chiropractor and a light exercise regimen that includes stretching once you've had your check-up.
394777
Usually through exercise.  The better shape you're in, the more energy you have.  Kind of ironic, isn't it?  When you're out of shape, you don't feel like exercising due to lack of energy.
543661
The fatigue could indicate liver issues. The heavy breathing could be part of the fatigue process, also could indicate early congestive heart failure. See your doctor.
871356
Its possible you aren't getting enough sleep.\n\nIts possible you aren't eating right.  Maybe you're not getting enough protein or even fat, both of which can make you feel a little more energetic.\n\nIf there's any chance you have a little depression you would not always have the energy to work out.\n\nIf you live under unrelenting stress its possible your adrenal gland has "run out of juice" and cannot produce sufficient cortisol for you to be able to exercise without feeling depleted.  ("Adrenal fatigue" causes people to feel depleted rather than invigorated by exercise.)
449693
because they are bloch the B receptors which are responsible for heart contractions\n\nthen heart rate and contraction decrease ,this may lead to fatigue
656464
With vigorous exercise, your muscles use anerobic energy and build up lactic acid.  That is what causes the pain.  Rest for a bit, the lactic acid gets reconverted to other forms of energy, and it doesn't get tired anymore.
909888
Too much stress and not enough exercise come to mind
303484
If it really bothers you, see a doctor. Fatigue is a symptom of all kinds of conditions.  It could a be a thyroid problem, epstein barr, fibromyalgia, depression, etc.It could a be a million things or it could be nothing. The point is if it is impacting your life negatively, you should really see someone about it. You may actually have a condition, and it is probably treatable- then you can get on and enjoy your life.
308431
Yeah, you didn't cool down properly. Drink plenty of water, don't stop moving right after the exercise (as in, don't go to sleep), and make sure you're getting enough electrolytes, vitamins and protein.
1111649
It's pretty common with people which do not perform intensive excercises every day.\n\nMy tip would be to try and breathe in a rhythm to the beat of your jogging footsteps, and to keep taking deep breaths at all times to ensure enough oxygen is suplied to your muscles - you won't get tired so quickly.
742532
Wow you're lucky.\nDepends, how much do you weight? \nIf you're at a good weight but still tired, treatment for fatigue could be a chance in exercise regime or diet. Maybe more outside activity - \nIf you're underweight and fatigued, eat more. \nIncrease omega-3 consumption. Increase Lean protein consumption. \nSoy products are like dreams :)
326211
When you exercise, sugar is broken down into different chemicals, to produce energy for muscles. As long as you get all the oxygen you need, the final products are carbon dioxide and water, but if you exercise so vigorously that you can't get the oxygen that you need, the reactions stop, causing a chemical called lactic acid to accumulate in your muscles and spill into you bloodstream. \n\nLactic acid causes muscles to hurt and makes you feel tired. You breathe hard and fast and slow down to catch up with your oxygen debt, which converts lactic acid into carbon dioxide and water that are blown off as you breathe. Blood levels of lactic acid lower and your muscles stop hurting. A pace that you can hold breathing deeper and faster, but not gasping for breath is called the lactic acid threshhold and is the training level for most competitive athletes.\n\nDuring intense exercise, such as sprinting type activities, when the rate of demand for energy is high, lactate is produced faster than the ability of the tissues to remove it and lactate concentration begins to rise. This is a beneficial process since the regeneration of NAD+ ensures that energy production is maintained and exercise can continue. Contrary to popular belief, this increased concentration of lactate does not directly cause acidosis, nor is it responsible for muscle pain or "burning". This is because lactate itself is not capable of releasing a proton, and secondly, the acidic form of lactate (lactic acid) cannot be formed under normal circumstances in human tissues. Analysis of the glycolytic pathway in humans indicates that there are not enough hydrogen ions present in the glycolytic intermediates to produce lactic or any other acid.\n\nThe acidosis that is associated with increases in lactate concentration during heavy exercise arises from a completely separate reaction. When ATP is hydrolysed (split) for energy, a hydrogen ion is released. It is these hydrogen ions that are primarily responsible for the decrease in pH. During intense exercise, oxidative metabolism (aerobic) cannot produce ATP quick enough to supply the demands of the muscle. As a result, glycolysis (i.e. anaerobic metabolism) becomes the dominant energy producing pathway as it can form ATP at high rates. Due to the large amounts of ATP being produced and hydrolysed in a short period of time, the buffering systems of the tissues are overcome, causing pH to fall and creating a state of acidosis. This may be one factor, among many, that contributes to the acute muscular discomfort experienced shortly after intense exercise.\n\nAlthough it is not firmly established, it is possible that lactate may contribute to an acidotic effect via the strong ion difference, however this has not been well investigated in exercise physiology research and so its contribution is still uncertain.
1029670
it woldnt make sense to workout if it doesnt do anything for u if ur still tired
576793
Are you having some kind of small meal or snack before? It could be that you are bottomed out on your blood sugar levels and that would make you very tired during a workout. Also, a 2 hour intensive workout is pretty long. You may wish to have  some Gatorade after one hour and I bet that would keep you going during the second hour. just as you can drive very far on an empty tank, your body needs fuel too.
576168
You need to boost your system with a lot of fresh fruit and veg.  build your energy levels back up.  however be aware that a long viral infection could lead to chronic fatigue syndrome.  give yourself a month to improve and if you are still feeling tired or things get worse consult your doctor.
1123245
Do you mean muscle cramp?  If so, it's usually an electrolyte imbalance, caused by sweating too much during exercise without replenishing electrolytes.  A good energy drink, taken regularly during exercise, should help avoid it.