Post by marathondude on Sept 5, 2008 10:37:12 GMT -5
Fatigue and Dehydration
Running can sure be tiring. How often when you finish a run are you just worn out? Sometimes it may be fatigue from an effort that is faster or longer than your norm. On other occasions you could be experiencing dehydration from not replacing water and electrolytes lost due to heavy sweating. Or you may be experiencing both fatigue and dehydration. There is an important distinction and it is paramount that you know and realize the difference.
Fatigue is extreme tiredness resulting from excessive activity. If you increase your weekly long run from eight miles to twelve miles you may be much more tired afterward. If you add a track session to your training plan you will most likely be exhausted when you finish. If you start doing tempo runs you will probably be worn out. This is okay as it’s a normal response. Your body will adapt to the increased stress which accompanies fatigue and you will be stronger the next time you schedule a similar training session.
Dehydration is a lack of adequate water in the body resulting from inadequate fluid intake and excessive sweating. Several contributing factors lead to dehydration. Many runners start the day in a state of dehydration and do not properly hydrate prior to running. We easily lose a pint or more of fluids while we sleep through perspiration and respiration. We must drink a pint of fluid just to “break even.” Then it is important to drink more and get some “water in the tank” before running, especially if the weather conditions are hot and humid or if a lengthy run is planned. Next we must drink during our run either at water fountains, by looping past our house where fluids are stationed or from bottled fluids that we placed along our running route the night before our run. Finally, we need to replenish by drinking afterward.
Fatigue can occur without dehydration but the opposite isn’t true. If you become dehydrated you will feel fatigued. How can you tell if you are both fatigued and dehydrated? The easiest way is to weigh yourself before and after your run. If you have lost more than two per cent of your body weight you have light dehydration; at three per cent, moderate dehydration and at five per cent, severe dehydration. A quick indicator is your pulse rate immediately after completing a run. If you take your pulse regularly you will have an idea of your typical pulse rate after similar training runs. For example, if your pulse rate after seven miles at 8:30 pace is usually around 135 and instead it is 160, there is a good chance that you are dehydrated.
When we run we want to include elements of training that are good and to avoid those which are bad. Fatigue is good as it’s our body’s way of telling us that we just did something difficult. Dehydration is bad as it’s our body’s response to not being adequately fueled for the task at hand. So do all you can to be hydrated and to realize the training effects of fatigue.
MarathonDude has 35 years of competitive running and racing experience highlighted by a marathon PR of 2:22:34. He is a regular writer for Florida Running & Triathlon magazine. At www.garycohenrunning.com you will find over a dozen FR&T articles, interviews with running personalities and dozens of “All in a Day’s Run” essays.
Running can sure be tiring. How often when you finish a run are you just worn out? Sometimes it may be fatigue from an effort that is faster or longer than your norm. On other occasions you could be experiencing dehydration from not replacing water and electrolytes lost due to heavy sweating. Or you may be experiencing both fatigue and dehydration. There is an important distinction and it is paramount that you know and realize the difference.
Fatigue is extreme tiredness resulting from excessive activity. If you increase your weekly long run from eight miles to twelve miles you may be much more tired afterward. If you add a track session to your training plan you will most likely be exhausted when you finish. If you start doing tempo runs you will probably be worn out. This is okay as it’s a normal response. Your body will adapt to the increased stress which accompanies fatigue and you will be stronger the next time you schedule a similar training session.
Dehydration is a lack of adequate water in the body resulting from inadequate fluid intake and excessive sweating. Several contributing factors lead to dehydration. Many runners start the day in a state of dehydration and do not properly hydrate prior to running. We easily lose a pint or more of fluids while we sleep through perspiration and respiration. We must drink a pint of fluid just to “break even.” Then it is important to drink more and get some “water in the tank” before running, especially if the weather conditions are hot and humid or if a lengthy run is planned. Next we must drink during our run either at water fountains, by looping past our house where fluids are stationed or from bottled fluids that we placed along our running route the night before our run. Finally, we need to replenish by drinking afterward.
Fatigue can occur without dehydration but the opposite isn’t true. If you become dehydrated you will feel fatigued. How can you tell if you are both fatigued and dehydrated? The easiest way is to weigh yourself before and after your run. If you have lost more than two per cent of your body weight you have light dehydration; at three per cent, moderate dehydration and at five per cent, severe dehydration. A quick indicator is your pulse rate immediately after completing a run. If you take your pulse regularly you will have an idea of your typical pulse rate after similar training runs. For example, if your pulse rate after seven miles at 8:30 pace is usually around 135 and instead it is 160, there is a good chance that you are dehydrated.
When we run we want to include elements of training that are good and to avoid those which are bad. Fatigue is good as it’s our body’s way of telling us that we just did something difficult. Dehydration is bad as it’s our body’s response to not being adequately fueled for the task at hand. So do all you can to be hydrated and to realize the training effects of fatigue.
MarathonDude has 35 years of competitive running and racing experience highlighted by a marathon PR of 2:22:34. He is a regular writer for Florida Running & Triathlon magazine. At www.garycohenrunning.com you will find over a dozen FR&T articles, interviews with running personalities and dozens of “All in a Day’s Run” essays.