Salt? Friend or Foe?
You know, we receive some very interesting emails from athletes. They ask some really good questions that sometimes their traditional medical doctors cannot answer. You have to love athletes. They are brutally honest, forthright, and obsessive. That’s what makes them able to do what they can do. They are an amazing breed of people. Here was a recent question I received via email from a triathlete:
“I have been putting salt on everything I can think of these days and that is not like me. I normally do not add salt when I am cooking because of all the salt already added......So do you think that this salt craving is related to my workouts? I also know that I get calf cramps in a very wicked way, if I do not watch my electrolytes....Any thoughts...”
What we find in our practice when someone, particularly an athlete, is craving salt, it is usually one of two things or a combination of both, however, it could be related to something more serious.
1. Fluid and/or electrolyte imbalance
2. Adrenal fatigue
The adrenal gland is the stress gland, that when exhausted causes you to crave salt. What we do in our office is start with testing the patient’s electrolyte balance and pH levels with a Nova 8 panel. This gives us blood pH, sodium, chloride, potassium, calcium, and magnesium levels. We start there. If abnormalities are found, such as low serum sodium or magnesium levels, we start the patient on supplementation. Sometimes this requires an IV, sometimes intramuscular injections, and sometimes supplementation can be done orally. It depends on the severity of the case.
Electrolyte loss during workouts
The purpose of taking in nutrients during races is essentially to refuel muscles. The benefits of replenishing energy and fluid during racing (and training, too, for that matter) include better performance, delay of fatigue, and even reduction in post-exercise muscle damage. There are two components of muscle fueling: fluid and energy.
Fluid: Most athletes understand the relationship between exercise and water loss. Sweat is the body's coolant. During an intense workout, your muscles generate heat, which is carried by your blood to the surface of your skin. Your sweat glands release sweat (which is made up of water and electrolyte minerals) that evaporates, cooling the skin and the blood just underneath the skin. Cooled blood then flows backs to cool your body's core. Sweating is therefore an essential mechanism for regulating body temperature. But the loss of water that comes with perspiration reduces the effectiveness of this cooling system and limits the capacity of your blood to carry vital nutrients, such as glucose, fatty acids, and oxygen, to working muscles. The capacity of the blood to remove the byproducts of metabolism, including carbon dioxide and lactic acid, is compromised as well. These collective effects of dehydration translate into a steady decline in endurance performance. Dr. Hauser and I, along with many of our training buddies, have noticed this problem ourselves, particularly when exercising in very warm weather. There is a point in time where the athlete’s performance will just steadily decline, almost to the point of no return. Therefore prevention of this by utilizing salt and/or electrolyte tablets and proper hydration is key.
Athletes should try to fully replace fluid and electrolyte losses that occur during exercise. However, it is seldom possible to achieve this ideal. Research has shown that most athletes are unable to tolerate drinking fluids at a rate exceeding 80 percent of the rate of fluid loss. When too much fluid is consumed, bloating, and nausea can result – and we have probably all experienced that at one point in time. It’s not a pleasant feeling. As a general rule, it is a good idea for the athlete to consume as much fluid as you can tolerate during workouts and competitions. Athletes can often increase their tolerance for fluid consumption during exercise simply by practicing it consistently. This is another thing that athletes are notoriously bad at doing. Try it – it could help you!
Different people lose fluids at different rates during exercise. I for one am a huge sweater. I sweat a lot when it is only 40 degrees outside. These winter months have been great for me, because I have kept the sweating and resultant fluid and electrolyte loss problem to a minimum! We have another friend, Tim, who trains with us who is also a huge sweater. When we work out in the basement on our cycling trainers, he is the first one to develop a huge puddle under his trainer!
You can estimate your own standard rate of sweat loss by weighing yourself immediately before and after a typical workout and figuring in fluid consumed and urine excreted during the workout. For example, say an athlete loses one pound thirteen ounces in a 60-minute workout during which he neither drinks nor urinates. This is a total of 29 ounces lost (one pound equals 16 ounces). Therefore, the athlete should try to replace 29 ounces of fluid for each hour of exercise. If statistics are correct, the athlete can expect to be able to replace only 80 percent of this amount - about 23 ounces. Note that higher environmental temperatures and higher exercise intensities increase the rate of fluid loss. Thus, in hot weather and at high intensity levels, it is particularly important that you drink as much fluid as you can tolerate.
What about electrolytes? Remember, water alone is not sufficient, because drinking water does not replace electrolyte losses that occur through perspiration. Rates of electrolyte loss also vary from one athlete to the next, but in general it is easier to fully compensate for electrolyte losses during exercise than for water losses. Most sports drinks are formulated to provide electrolytes and water in the proper ratio to make up for the effects of perspiration. If you are one of those athletes who sweat more than average, you will most likely need to use electrolyte capsules to keep proper fluid-electrolyte balance.
Is Thirst a Good Indicator?
In order to understand how the body replenishes lost fluids, you should first understand what causes thirst. The thirst sensation is dependent upon two factors: the body’s blood volume, and the concentration of salts, or electrolytes, in the blood. When an athlete loses fluids during exercise through sweating, the blood volume consequently decreases. This results in a corresponding increase in the concentration of electrolytes in the blood, which stimulates thirst, which causes you to drink water.
Recent research has shown that the body absorbs more fluid when electrolytes such as sodium are added to water. In one study, six volunteers underwent two exposures to heat and then engaged in an exercise session that caused mild dehydration, resulting in a two- to three-percent decrease in body weight. Each volunteer then drank either water or a water and sodium solution to replenish fluids. During the three-hour rehydration period, subjects who drank water alone restored 68 percent of the fluid they lost, while subjects who drank the sodium solution replaced 82 percent of their lost fluids.
What caused this marked difference? The addition of sodium to water helped to maintain the salt-dependent factor of the thirst drive, prompting the volunteers to continue drinking. This led to a more complete restoration of body fluids within the three-hour recovery period. We find that supplementing with salt tablets is an easy way to remedy this issue.
Minerals We Need
There are four main electrolytes that are lost in sweat during exercise and need to be replaced through consumption of a sports drink that contains them in adequate quantities. Sodium and chloride are electrolytes that help maintain the volume and balance of all the fluids outside your body’s cells, such as blood. Sodium plays a particularly important role because it helps transport nutrients into cells, so they can be used for energy production as well as tissue growth and repair. In addition, sodium functions in muscle contraction and nerve impulse transmission. Excessive loss of body salts is known as hyponatremia, and it can be dangerous. Potassium is necessary for nerve transmission, muscle contraction, and glycogen formation. It also aids in maintaining cardiovascular system function. Excessive potassium loss can cause muscles to contract involuntarily, resulting in painful cramps that can stop you in your tracks. In addition, potassium losses can lead to heat intolerance.
Magnesium is found in all of the body’s cells, although it is most concentrated in the bones, muscles and soft tissues. It’s a necessary element in over 300 enzyme reactions involving nerve transmission, muscle contraction, and especially ATP production. Low blood magnesium levels during exercise have also been cited as causes of muscle fatigue and irregular heartbeat.
The bottom line on fluid and electrolyte balance is just that – BALANCE. If you are having trouble with this issue, we would be happy to test your electrolyte status right while you wait. It’s better to know what is going on, than to just assume. This is too serious of an issue to ignore.
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