In general hiking activities, an average of 2–4 litres of water is lost per day; during prolonged hiking in hot weather, the amount of water lost increases significantly, typically reaching 5–7 litres per day.
The saying “hikers should drink as little water as possible” is outdated. The serious health risks posed by dehydration have been medically confirmed.
Please see: Consequences of Body Dehydration (percentage of body weight lost as water)
Greater than 2% — changes in body temperature.
Greater than 3% — decreased muscle endurance.
Greater than 4% to 5% — reduced strength and endurance.
Greater than 6% — cramps, stroke, or coma due to inability to dissipate heat.
Greater than 11% — severe kidney dysfunction, even death.
For example: if 3% of body weight in water is lost (for someone weighing 120 lbs, that’s 1.63 litres), blood concentration increases, putting more strain on the heart; a loss of 4%–5% makes it difficult to concentrate, affecting marching ability and causing abnormal movement patterns, which greatly increases the risk of falls. A loss exceeding 6% may lead to fatal accidents.
Conclusion: Proper hydration is a crucial element in ensuring the safety of hiking and mountaineering activities.
Water Requirements During Outdoor Activities:
1. Replenish water early, don’t wait until you feel parched or thirsty.
2. Follow the principle of small amounts at frequent intervals—about 100–150 ml every 15–25 minutes.
3. During hiking, aim to roughly balance water loss with intake.
4. Appropriately replenish sports drinks to quickly provide your body with energy and electrolytes.
If you’re taking part in outdoor activities in hot summer, freezing all the necessary water and sports drinks into ice blocks for transport can be a delightful solution. As you move about in the high heat, having cool and refreshing drinks to replenish yourself along the way will be a pleasure. Moreover, drinking iced beverages in the sweltering summer not only lifts your mood but also helps indirectly regulate your body temperature back to normal, preventing and avoiding heat-related illnesses such as heatstroke that are common during outdoor activities in harsh hot conditions.
What Is Real Sports Drink?
Sports drinks are formulated according to the physiological demands of physical activity. They are designed to specifically replenish nutrients lost during exercise, help maintain or enhance athletic performance, and accelerate recovery from fatigue. Therefore, they should have the following basic characteristics:
Adequate sugar content: Due to intense muscle activity, glycogen stores are heavily depleted, and muscles increase their uptake of blood glucose, leading to a drop in blood sugar levels. Without timely replenishment, working muscles can become fatigued. Additionally, since over 90% of the brain’s energy comes from blood sugar, a drop in glucose weakens the brain’s ability to regulate physical activity and induces fatigue.
Appropriate electrolytes: Sweating during exercise causes significant loss of electrolytes such as potassium and sodium, leading to fatigue and even cramps, which reduce athletic performance. The sodium and potassium in sports drinks not only replace what’s lost through sweat but also help retain water within blood vessels, ensuring better hydration. If the electrolyte content is too low, replenishment is ineffective; if too high, it raises the osmotic pressure of the drink, causing gastrointestinal discomfort and slowing the absorption of fluids.
No carbonation, no caffeine, no alcohol: Carbonated drinks can cause bloating and stomach discomfort; caffeine has a diuretic effect, increasing water loss—while exercise itself leads to substantial loss of water and electrolytes. Moreover, caffeine and alcohol stimulate the central nervous system, hindering post-exercise recovery.
Hypertensive patients should not drink excessive sports drinks
While light exercise is indeed beneficial to health, hypertensive individuals who consume sports drinks after exercise may experience elevated blood pressure. Because hypertension patients must limit salt intake—and salt contains sodium, which raises blood pressure—sports drinks have relatively high sodium content, which can further elevate blood pressure in these patients. While sports drinks pose no issues for healthy individuals or those with low blood pressure, hypertensive individuals who drink them indiscriminately during exercise are highly prone to strokes. Therefore, hypertensive patients should not drink large amounts of sports drinks.
Do You Need Sports Drinks?
Replenishing fluids during exercise is a critical step. During halftime in sports competitions or breaks in training, athletes often grab a bottle of water and drink heartily. But is it plain water? No, because plain water dilutes the blood, causing more water loss through sweat and easily disrupting the body’s electrolyte balance. Then, is it fruit juice? Also no. Fruit juices and juice drinks with relatively high concentrations have high osmotic pressure, preventing quick absorption of their contents. In fact, it’s a new type of beverage—sports drink.
A certain sugar content
Sugar is the most economical and direct primary energy source for the human body. It is stored in the form of glycogen in skeletal muscles and the liver. Since the body's sugar reserves are limited, during exercise, if large amounts are consumed without replenishment, the muscles will become fatigued and athletic performance will decline. On the other hand, over 90% of the brain’s energy supply comes from blood glucose. A drop in blood sugar weakens the brain’s ability to regulate physical activity and leads to fatigue. Therefore, sports drinks must contain a certain amount of sugar. High-quality sports drinks primarily use oligosaccharides, which help replenish blood sugar, allowing the brain and muscles to continuously absorb sugar during exercise, thereby improving endurance, delaying fatigue, and accelerating post-exercise recovery. Oligosaccharide-based drinks also help lower blood lactate levels during exercise, increase muscle strength, and enhance workload.
An appropriate amount of electrolytes
Excessive sweating can lead to significant loss of electrolytes such as potassium and sodium, resulting in bodily fatigue or even cramps, which reduces athletic performance. The sodium and potassium in beverages not only help replace those lost through sweat but also aid in retaining water within the blood vessels, ensuring the body gets more adequate hydration. If the electrolyte content in the drink is too low, it won’t achieve the desired replenishing effect; if it’s too high, it increases the osmotic pressure of the drink, causing gastrointestinal discomfort and preventing the water in the beverage from being quickly absorbed by the body.
Low osmotic pressure
To ensure that the water and other nutrients in the drink pass through the stomach quickly and are fully absorbed, the osmotic pressure of the drink should be lower than that of plasma — that is, it should be a hypotonic drink. The types and amounts of sugar and electrolytes contained in the beverage are the direct determinants of its osmotic pressure. Nutrient-rich sports drinks can maintain low osmotic pressure even when containing various types of sugars and inorganic salts.
No carbonic acid, no caffeine, no alcohol
Carbonic acid can cause bloating and discomfort in the stomach. Drinking large amounts of carbonated beverages may lead to symptoms such as stomach spasms or even vomiting. Caffeine and alcohol have certain diuretic and dehydrating effects, which can further exacerbate fluid loss. In addition, both substances stimulate the central nervous system, which is not conducive to fatigue recovery.
Some sports drinks also contain additional ingredients, such as B vitamins, which can promote energy metabolism; vitamin C, which helps eliminate free radicals, reduce their damage to the body, and delay the onset of fatigue; and moderate amounts of taurine and inositol, which can promote protein synthesis, prevent protein breakdown, regulate metabolism, and accelerate the elimination of fatigue, among other benefits.
Because sports drinks meet the above basic criteria, they can promptly replenish fluids, maintain normal fluid balance; quickly restore energy and stabilize blood sugar levels; timely provide energy; improve and enhance metabolic regulation capabilities; and improve thermoregulation and cardiovascular function. Therefore, sports drinks not only quench thirst but also address the body’s need for hydration.
Principles for replenishing sports drinks during exercise
Drinking 500 milliliters of fluid two hours before exercise can increase glycogen reserves in muscles and the liver. During exercise, consuming small amounts frequently can prevent stomach discomfort. Drinking 125–250 milliliters of fluid every 15–20 minutes can prolong exercise duration and delay the onset of fatigue. After exercise, replenishing lost fluids can speed up the recovery of lost water, sugar, inorganic salts, trace elements, etc., and promote rapid restoration of muscle glycogen, thereby eliminating fatigue. The method is to replenish 1000 milliliters of fluid for every 1000 grams of body weight lost. Choosing sports drinks during fitness activities can quickly replenish fluids, energy, and electrolytes lost through sweating, effectively maintaining or even further improving the body’s condition during or after exercise.