Reasons to hydrate
For athletes of all ages, drinking more fluids is an easy first step to solid performance fueling. During a practice session, any drop in body weight is due to water loss. As little as a two percent decrease in body weight during training can decrease performance during that session by up to 10%! In fact, a decrease in focus and concentration begins at as little as a 1.5% total body weight decrease. For a 150 pound athlete, that is a loss of only 2.5-3 pounds of water weight during training. So, be sure you are drinking fluids during training!
Staying hydrated throughout the day will lead to the following seven benefits that you will feel not just during workouts but throughout the entire day:
- Better energy
- Better concentration which leads to better decision-making and focus
- Decreased number of headaches, lightheadedness and tiredness that often comes with a dehydrated body
- Less overall strain on the heart during and after training, as the body can more easily regulate temperature and cool the body quickly
- Better protection of joints and ligaments for injury prevention
- Better recovery from training and competition
- Less chance of muscle cramping
Hot Topic! Should you drink chocolate milk after a workout?
Yes! Chocolate milk provides the perfect amount of carbohydrate and protein to help recover tired muscles after a workout. Chocolate milk also contains electrolytes to replace what was lost in sweat. Because chocolate milk is a liquid, it is quickly delivered to muscles for fast recovery. Plus, it tastes great, is affordable and is easy to find!
Fluid balance- what is it?
Fluid balance is defined as the balance of fluids coming in and out of the body. Fluids come in mainly from food, liquid and metabolic production. Fluid is lost through respiration, digestion and sweat losses. Of these, the main way we lose water is through sweat. As an athlete, achieving fluid balance will lead to the best usage of the food you eat, leading to optimal energy, recovery and protection from illness and injury.
Our bodies are about half water by weight. However, within that water is also something called electrolytes. You may have heard this term when learning about sports drinks. The major electrolytes in the body are sodium, chloride, potassium, magnesium, and calcium. They play a role in helping muscles contract and relax. Sodium and chloride are mainly stored outside of the body’s cells while most of the potassium is stored inside the body’s cells. The amount of electrolytes inside and outside of the body’s cells is carefully balanced by your body to maintain certain levels.
These electrolyte levels can be thrown off when athletes sweat, mainly due to sodium and chloride losses. Potassium, calcium, and magnesium can also be lost in sweat, but the amount is so small that deficiencies are rare. Electrolyte losses can vary greatly among athletes due to these main three contributors:
- Environment: Athletes who suddenly begin training in a much warmer temperature than normal for them often lose more electrolytes than those who are more used to training in that environment.
- Fitness Level: The more highly trained an athlete is, the fewer electrolytes he tends to lose in sweat, as the body becomes more adjusted to training.
- Genetics: Some athletes naturally have a higher sweat rate, so they will lose more fluid and electrolytes than others.
You may have noticed that some of your teammates sweat very little, while others sweat a lot! Some have salt crystals on their skin and around the neck of their shirts, while others don’t have this at all. Total sweat loss during exercise can vary from 8-80 ounces per hour depending on the type of athlete and type of training session! It’s good to understand how much you sweat to better replace that sweat lost during and after training.
So why does this matter?
Losing a lot of sodium and water through sweat disturbs fluid and electrolyte balance in the body. Drinking too much water during or after training can dilute blood sodium levels, causing muscle cramping mid-practice, during or after performance or potentially causing more severe outcomes. This is called hyponatremia. Signs and symptoms of hyponatremia include headache, vomiting, swollen hands and feet, confusion and wheezy breathing. To prevent hyponatremia, it is important for athletes to use an electrolyte-containing beverage during hard training or any training that lasts over 60 minutes as well as after training to replace both water and electrolytes.
USOC Hydration Fact Sheet – possibly link?
Hot Topic! How dairy can support fluid balance?
For rehydration post-activity, be sure to drink enough total fluid and that the fluid contains electrolytes. Milk contains both! Studies have shown that non-fat milk is effective after exercise to rehydrate and restore fluid balance – and even better than a sports drink. This is likely due to the great taste (especially of the flavored varieties), which drives athletes to drink more as well as the total sodium content (about 100mg per eight fluid ounces). Studies have also shown that milk protein is more effective for rehydration after a workout than a similar amount of carbohydrate calories.
How do I stay hydrated?
To stay hydrated, focus on fluid intake throughout the day – not just around and during training. Try these four tips:
- Start early by drinking a full glass of water when you wake up; sip liquids often throughout the day.
- Always carry a water bottle with you.
- To assure you drink enough during training, weigh yourself before and after exercise. Drink three cups of fluid for every pound lost during training.
- Check urine color throughout the day. Urine should be light yellow versus saturated or dark yellow.
Aim to drink about half of your weight in ounces of fluid daily outside of training. So, if you weigh 150 pounds, that is 75 ounces, or about ten 8-ounce cups of fluid daily. Spread this fluid intake throughout the day. Consume milk or 100% fruit juice (up to 4-8 fluid ounces daily) at meals and water in between meals. If you do not like water, try flavored waters. After exercise, try flavored milk as a great recovery option. Or mix flavored milk or yogurt with fruit and blend into a smoothie! Fruit has a high water content, so will contribute to total hydration.
During exercise, hone in on your hydration strategy by using the tips in this table:
*Per 8 oz, a proper sports drink should include 10-20gm carbohydrate, 50-200mg sodium and 20-100mg potassium.
Use these three steps to monitor your hydration status throughout the day!
Step 1: Evaluate your pee color. How often do you go to the bathroom? As the body is better hydrated, urine will become a lighter yellow color. Avoid very dark urine color.
Step 2: Notice your thirst – The body will trigger thirst when the body becomes about one percent dehydrated. A level of dehydration of two percent body weight is when performance is negatively impacted. Therefore, it is a great idea to drink when you feel thirsty.
Step 3: Take pre- and post-weights around exercise. Monitor total weight losses to assure the amount you are taking in during exercise is not too little or too much. Again, you should lose no more than two percent of your body weight during training or competition sessions.
Both during and outside of training, avoid energy drinks that contain high amounts of caffeine which can increase blood pressure, decrease sleep quality, increase risk of injury and overall decrease performance. Energy drinks are not a good hydration or rehydration fluid.
Be on the look-out for signs and symptoms of dehydration throughout the day and during training. These include:
- Poor concentration
- Early tiredness during training
- Feeling like the workout is harder than it really is
- Poor heat tolerance
- Poor recovery
- Frequent muscle cramps
- Nausea or vomiting
- Severe dehydration: elevated heart rate
Hot Topic! Chocolate milk or sports drink? How do they stack up?
Sports drinks are a great choice for hydration, but only when your body is physically active to the intensity that you are sweating for a long period of time (over 45-60 minutes). If that doesn’t apply, water is sufficient. Sports drinks consist of fluid, sugar and electrolytes – three things your body needs immediately before, during and/or after training. Do not drink sports drinks at meals or snacks. Sports drinks are not a great recovery drink because they don’t contain what is really needed for recovery – protein!
Due to its protein content, chocolate milk would not be a great choice for hydration during activity. However, chocolate milk provides the perfect amount of carbohydrate and protein to refuel and rebuild exhausted muscles after a workout! It also contains fluid to rehydrate and electrolytes to replenish what is lost in sweat. Chocolate milk contains nine essential nutrients that an athlete needs, including some not typically found in other recovery drinks, along with eight grams of protein per cup. It also is a great source of calcium and vitamin D to help support strong bones and prevent bone-related injuries (Abrams et al). Because chocolate milk is a liquid, it is quickly digested and delivered to muscles for fast recovery. Plus, it tastes great, is extremely affordable and is easy to find! Can’t tolerate lactose? Try lactose-free milk!
So how do sports drinks and chocolate milk stack up? They were designed and are intended for two different nutritional purposes – sports drinks for during activity and chocolate milk for after activity. So, choose and use intelligently to achieve your best performance and recovery.
Abrams GD, Feldman D and Safran MR. Effects of vitamin D on skeletal muscle and athletic performance. J Am Acad Orthop Surg 2018;0:1-8
Davey T, Lanham-New SA, Shaw AM, et al: Low serum 25-hydroxyvitamin D is associated with increased risk of stress fracture during Royal Marine recruit training. Osteoporos Int 2016;27(1):171-179.
DeLuca HF: Overview of general physiologic features and functions of vitamin D. Am J Clin Nutr 2004;80(6 suppl):1689S-1696S.