In 1965, a group of researchers noticed the University of Florida Gators football team struggling in the intense heat, many of them suffering from heat exhaustion during practices and games. In a lab, this group of researchers collected and studied the sweat of the players to then create a fluid that mimics the composition of sweat. The researchers theorized that replacing the fluids and electrolytes lost in sweat would help players push through the heat and enhance performance. The researchers lifted their glasses, took a sip, and promptly spit it out. The earliest form of Gatorade had been born, but the flavor needed quite a bit of work before it resembled that of the Gatorade we now see on shelves.
As the researchers had expected, the Gators performance throughout the season saw significant improvements after the introduction of this hydration solution. While there was certainly awareness around hydration and electrolytes prior to this, one might say that this was a dawn of a new age in hydration. In the coming years, a variety of sources (including the American College of Sports Medicine and Academy of Nutrition & Dietetics) would confirm that as little as a 2% decrease in body weight from sweat loss can result in significant declines in athletic performance. Maintaining adequate fluid intake is critical for all facets of health and fitness. Nearly all metabolic reactions in the body occur in water. In addition, water (and sweat) is needed to maintain body temperature during workouts. Without adequate fluid for sweat, the body overheats, resulting in various bodily functions running less efficiently (including muscles and the nervous system). As sports nutrition research would progress, we would come to find that the minerals, electrolytes, in water and often lost in sweat are just as critical to our overall hydration as water.
What are electrolytes? These are minerals found in the diet that carry a charge (also known as ions). These minerals are special because of this ionic charge, giving them special functions in the body. The primary electrolytes in the diet include sodium, potassium, magnesium, calcium, phosphorus, and chloride.
Sodium is the most predominant electrolyte lost in sweat. This is because sodium is the most abundant extracellular electrolyte. In other words, sodium prefers to exist outside your body cells and stay in your fluids. Potassium, on the other hand, is the predominant intracellular electrolyte (preferring to exist inside body cells). This balance of sodium outside the cell and potassium inside the cell is critical to maintaining a cell’s health and function. Body cells are constantly pumping sodium outside the cell and potassium in. This exchange helps to transport nutrients into a cell and waste out of a cell (think of it as the electrolyte highway!). In addition, adequate intake and balance of sodium and potassium helps nerve impulses and muscle contractions operate properly, both of which are critical during any form of physical activity. Plus, a proper balance of sodium to potassium helps regulate and maintain a healthy blood pressure. What is this “proper balance” of sodium and potassium I refer to? In general, a ratio of about 2:1, potassium to sodium, tends to be the ideal balance of these electrolytes. For most adults, the sodium tolerable upper intake level (UL) recommendation is 2300mg per day, while the potassium recommended daily allowance (RDA) of potassium is 4700mg per day. Unfortunately, many people under consume potassium (due to a diet lower in fresh fruits and vegetables) and over consume sodium (due to a higher concentration of processed foods in the diet). This will throw off the balance of our sodium and potassium intakes, hindering out exercise capacity and general health. How do we regain balance?
Seek out foods higher in potassium to include in your diet! In general, most fruits and vegetables are abundant in potassium. That being said, some examples of potassium superstars include:
- White Potatoes
- Kiwi fruit
Other major electrolytes of concern are calcium and magnesium. Both of these electrolytes work synergistically to facilitate muscle contractions and relaxation. In fact, magnesium is often recommended for individuals with chronic muscle cramps, as it has been known to help alleviate this issue. In addition, magnesium is involved in over 300 metabolic processes in the body. In other words, it is hard to overstate the significance of this mineral. Magnesium helps the body create energy from food, build proteins, regulate blood glucose, manage blood pressure and heart rate, maintain bone strength, maintain immune function, and much, much more! On the other hand, calcium is equally as significant. In fact, calcium is the most abundant mineral in the body. Many know that calcium is critical for bone health, but as mentioned above, it is also critical for muscles to both contract and relax. Insufficient calcium can result in muscle cramps, spasms, and overall weakness. In addition, adequate calcium intake has been shown to help manage blood pressure and possibly reduce risk of cardiovascular disease. In a day, most adults need 1000 to 1200mg of calcium per day, while most adults need about 400mg of magnesium in a day. Most adults do not get adequate magnesium, particularly since this mineral found in lower amounts in most foods. Some (but not all) adults get adequate calcium in the diet, but you may want to seek out additional food sources, particularly if you are someone that typically avoids dairy for any reason.
Good sources of calcium?
- Dairy foods
- Leafy greens
While you’re at it, pick up some foods high in magnesium, too:
- Leafy Greens
Notice some overlap? Nature is pretty good at including the nutrients we need in proportions our body prefers. All the more reason to include fresh fruits, vegetables, and whole plant-based foods into the diet often!
The next time you are bearing through the high heat of the summer and think about hydration, don’t forget the whole picture of hydration: fluids and electrolytes. While drinking plenty of water is important, the minerals in your diet play an equally vital role. In fact, at least 20% of your daily water intake comes from the food you eat and nearly all of the electrolytes in your diet come from your food selections. While it may not be what you expected, your food selections are just as critical to your hydration as the water you drink! Before you reach for Gatorade or some other electrolyte/hydration supplement, ensure that you’re getting adequate minerals from your diet first!