Most people understand that hydration is important, but very few know how much water they should be drinking on a daily basis. When we exercise, a wide variety of factors impact the rate at which we sweat. For example, the change in ambient temperature can increase sweat rates by up to 1 liter per hour. Additionally, exercise intensity and duration can cause sweat rates to vary from 0.5 liters to over 3 liters per hour. 
In addition to losing water, our bodies also lose electrolytes when we sweat. In a study examining electrolyte sweat losses during exercise, researchers observed that total sodium and chloride losses increased by 150% with increased exercise intensity. 
A second study focusing on electrolytes examined if changes in sodium serum levels were related to fluid balance in seasoned triathletes. The researchers noted that sodium serum levels in both men and women were correlated to changes in body mass during the event. 
The Importance of Electrolytes in the Body
Electrolytes consist of minerals or salts that dissolve in fluids, which then separate into positively and negatively charged ions. These electrically charged ions act as messengers throughout the body. They play important roles in various physiological processes including regulation of pH levels, nerve cell signaling, and muscle contraction. Electrolytes play an important role in fluid regulation by influencing absorption, retention, and transport in and out of cells.
There are a number of different electrolytes found in the human body, which need to be kept in balance for optimal function. The main electrolytes to be aware of, and the foods they can be found in, include the following.
Calcium: plays an important role in supporting bone and teeth health. It also plays a role in nerve signal transduction.
Common food sources: milk, cheese, sardines, chia seeds, soybeans, and sesame seeds.
Chloride: is involved in regulating fluid and pH balance in the body.
Common food sources: as a component of salt, most sodium rich foods will contain chloride as well.
Magnesium: is involved in over 600 enzymatic reactions in the body. Magnesium plays a role in bone formation and the synthesis of both DNA and RNA.
Common food sources: dark chocolate, pumpkin seeds, brazil nuts, cashews, spinach, and mackerel.
Phosphorous: plays a major role in DNA and RNA synthesis. It’s also involved in supporting bone health.
Common food sources: poultry, pork, seafood, organ meats, lentils, quinoa, and sunflower seeds.
Potassium: plays a role in skeletal and smooth muscle contraction. And it’s involved in the regulation of fluids and pH in the body.
Common food sources: avocados, sweet potatoes, bananas, coconut water, cantaloupe, apricots, and figs.
Sodium: supports proper nerve and muscle functioning. Sodium also plays a role in fluid regulation in the body.
Common food sources: salt, broths, cheeses, cured meats, pickles, cottage cheese, soups, and canned foods.
Hydration, Electrolytes and Performance
Hypohydration, or a reduction of total body water, is associated with decreased performance across a range of athletic markers. It’s important to note that even a low level of dehydration can impact performance.
Researchers evaluated 34 studies which examined the effects of dehydration on endurance exercise. The researchers concluded that if an individual loses 2% or more of their body mass in fluid, aerobic exercise and endurance performance becomes impaired. 
In a 2007 issue of Sports Medicine, researchers reviewed the effects of hydration and muscular performance with an emphasis on strength, power, and high intensity endurance exercises. The researchers noted that hypohydration appeared to consistently attenuate strength by about 2%, power by about 3%, and high intensity endurance by about 10%. 
In studies examining different team sport athletes, hypohydration was consistently linked with increased ratings of fatigue and perceived exertion, whereby athletes subjectively felt like they were working at a high level of output. 
Conversely, when athletes have personalized hydration plans, they’ve been found to show improved performance measures.
A study on collegiate athletes from different sports measured the impact that a personalized hydration plan, based on the individual’s sweat rate and sodium loss, had on performance. The athletes in the personalized hydration group showed improved jumping ability, faster tracking of moving objects, and improved heart rate recovery following moderate to hard training. 
Supplementing with Electrolytes
Drinking plain water can aid in hydration levels, but some research shows that consuming electrolytes in addition to water can assist in improving athletic performance.
A study on trained cyclists examined the effects of salt consumption on dehydrating exercise performed in the heat. The subjects participated in three randomized control trials, as a control group consuming plain water, a moderate salt and water group, and a high salt and water group. At the end of the study, the researchers noted that both of the salt groups had a better time trial performance compared to the control group, showing a 7.4% improvement. 
A second study examined the effects of salt supplementation before and during a half ironman event. The group that supplemented with salt had a lower total race time, less reductions in body mass following the race, and higher serum sodium and chloride levels. 
How Much Do You Need?
Everyone loses fluid at a different rate, making their hydration needs different. To calculate what you need, we can use the sweat rate calculation to help us perform better. To do your calculation, you will need to know your body weight in kg, and a water bottle filled with a measured amount of water.
Sweat Rate: This will be calculated in metric units
Body weight prior to training (kg) – body weight after training (kg) = weight loss (g)
Weight of water bottle before training (mL) – weight of water bottle after training (mL) = fluid volume consumed (mL)
(Weight Loss + Fluid Volume Consumed) / Time = Sweat Rate (ml/min)
Putting It Into Practice
Use your sweat rate number as a general idea of your fluid consumption needs around training. It’s important to remember that different factors impact your sweat rate, so measuring it under different conditions (e.g., light training vs hard training, cardio vs lifting, cooler vs humid climates) will give you a more accurate number. From there, experiment with fluid intake levels to see how they affect your performance. You don’t have to replace your exact fluid losses in a 1:1 ratio – for most people it would be uncomfortable to try drinking this much fluid during a workout – but be sure to replace your lost fluid throughout the course of the day. For further hydration support, consume electrolyte-rich food sources throughout the day to ensure all your needs are covered. Keep in mind that if you do prolonged, frequent, or very intense exercise on a regular basis, supplementing with an electrolyte drink mix would be a wise choice.
To support proper hydration for hard-training athletes, try supplementing with an electrolyte drink mix such as Hydra-Charge. Hydra-Charge is a powerhouse of flavor that provides you with the electrolytes: calcium, phosphorous, magnesium, sodium, and potassium.* It supports hydration before, during, or after intense training.* What’s more, Hydra-Charge 500 mg of freeze-dried coconut water and is combined with SPECTRA, which contains a blend of fruit, vegetable, and herbal extracts for antioxidant support.*