“Without proper hydration, everything else in the training of my athletes will fail.” - Jeff Waters, head strength and conditioning coach for pro fighters at Kronk Gym in Detroit and the boxing coach with the Detroit Red Wings.
Optimal hydration is critical to optimizing performance during training and an event, as well as for preventing injuries and aiding in post-game recovery. And a good method of hydration tracking can help you monitor your fluid and electrolyte needs.
“One thing I always stress to my clients is the importance of water and why it is vital for the human body. Whether you are losing weight, building muscle, preparing for a marathon or simply living your day-to-day life, water is essential,” says Dominic Kennedy, certified National Academy of Sports Medicine Personal Trainer, NASM weight loss specialist, NASM corrective exercise specialist, and NASM nutritionist.
“Being involved in ultra running, a mega endurance sport, hydration is absolutely key for me. It’s the difference between success and failure.” - Jenkins, founder of Pegasus Ultra Running and world record holder for the 870 mile Wales Coast path.
A majority (more than 50%) of athletes in professional sports, collegiate athletics, and high school and youth sports arrive at workouts dehydrated. Deviations on either end of the physiological range (being dehydrated or overly hydrated) can compromise both health and organ function.
Sara Callahan, fitness and nutrition coach with the Nutrition For Life Project, reminds us that “adequate water intake also helps protect our body temperature as we workout and compete; that’s why we sweat!” Furthermore, Nikki Walker-Nemickas, marathoner, 7-time champion bodybuilder and fitness instructor, adds, “for our athletes, we know water deficit can reduce blood volume, sweat rate, increase core and rate of glycogen use, causing fatigue, plateauing, and risk of injury.”
Beyond the risk of injury, poor hydration is felt immediately.
Hannah Daugherty, CPT-NASM, ACE, who serves on the advisory board for Fitter Living, adds, “a loss of water, or being dehydrated, can lead to an increase in fatigue and make it harder for your body to adequately control temperature, which can make your overall workout feel much harder than it already is.”
The Science: Hydration is normally maintained within a relatively narrow range (1% hyperhydration to 3% hypohydration). In addition to maintaining cardiovascular function, one of the primary purposes of proper hydration and sweating is core body temperature regulation. Therefore, dehydration can contribute to an increased risk of heat stroke, especially as temperatures increase.
Sara adds, “I have had athletes faint after workouts due to improper food and hydration levels coming into the workout; this most likely could have been prevented with a proper pre-workout snack and a glass of water 30-60 minutes before their workout.”
And this isn’t rare. Even top athletes can be caught off their guard.
Von Collins and his team at Complete Tri see this frequently as well. “When people say they “bonk”, they are usually suffering from a lack of electrolytes or hydration. We see it in every race, or long workout, and more often when it is sunny and warm.”
“Timing is also key - too much fluid in too short a period of time can actually do the opposite and cause something called hyponatremia. This is when the amount of salt and other electrolytes can become too diluted, and it can actually be life threatening,” says Jeff.
The Science: It’s possible to consume too much fluid during extensive physical activity. The condition typically associated with over hydration and electrolyte imbalance during extensive physical activity is called Exercise Associated Hyponatremia (EAH).
Athletes may present with symptoms such as confusion, seizures, and altered mental status in association with serum sodium levels <135 mmol/L in some cases, but in others there may be no symptoms present at all.
Though relatively rare, the incidence is rising alongside popularity in endurance events. For example, roughly 13% of 488 runners studied from the 2002 Boston Marathon had hyponatremia, and 18% of the 330 athletes who had just finished an ultramarathon were found to be hyponatremic. While the condition can be fatal, proper hydration before and during intense physical activity can significantly reduce the risk of hyponatremia.
Generally, hyponatremia becomes a greater risk for those involved in high intensity, high duration activities that last for several hours or more. In these situations, sodium, as well as water, becomes an important consideration.
Hannah says, “Since sodium is lost when we sweat (and will be different amounts for each person), monitoring is key, especially for high intensity activities that last more than 2 hours.”
As the level of intensity increases, so too does the importance of considering electrolyte balance.
Competing at the elite level means optimizing performance is critical during training and during competitions. And hydration is a necessary component for that optimization.
“Studies have shown that a simple 3-4% level of dehydration can impact your muscular endurance by up to 10%,” notes Jeff.
The Science: Suboptimal hydration strategies during training and competition are well known to reduce athletic performance through increased physiological stress, through an increase in heart rate, core temperature, and muscle glycogen use alongside a decrease in cardiac output, cognitive awareness, anaerobic power, and time to exhaustion. A study of collegiate athletes using personalized hydration and sodium replacement plans demonstrated improved anaerobic power, attention and awareness, and heart rate recovery time.
Rhys’s ultra-running team tracks his hydration during runs to ensure proper hydration and optimize mid-event. “Before we used to do this my energy levels would fluctuate, but now we are able to keep my levels more consistent and balanced.”
“The most important step of hydration happens before you even begin your workout,” says Jack Anderson, the founder of Sport Fitness Advisor. “You should begin drinking about an hour before you begin.”
The Science: The National Athletic Trainers’ Association Position Statement suggests using first morning urine voids to assess hydration and indicates that to optimize safety and performance, “it is important to begin an exercise bout euhydrated. To ensure euhydration before activity, an athlete should be mindful of individual cues, such as thirst, body weight, urine color, and voiding frequency.” Some studies specify keeping thirst low and urine color pale for at least 2 hours before an event.
Depending on the intensity of the upcoming event, some go even further. Von suggests “when we know we have a big exertion coming, we try to hydrate really well for a good 24 hours leading up to it.”
But it’s also important to hydrate during training or during the event, especially if the intensity is high, the duration is long, and the conditions are hot and humid.
Von adds, “On a bike, the rule of thumb is to take a good drink every 20 minutes or so. You can do it while you are moving, but you need to do it. Some long-distance riders actually set the alarm on their watch to remind them.”
Jeff suggests a similar strategy for ultra runners. “With an ultra run, it’s just you. You need to be conscious of your own hydration. The best way of doing this is to have some sort of stopwatch or reminder set for every 20 minutes.”
Hydration continues to play a role after an event, and is important to consider for a quick and healthy recovery.
Joanna K. Chodorowska, former triathlon coach and a current swim and nutrition therapy coach says, “I recommend that hydration be considered throughout the whole day, not just before, during and after training sessions. But often rehydration is key to be able to recover quicker after training.”
“The goal is clear pee by noon!” - Sara Callahan, Nutrition For Life Project.
Urine output is one of the best and most widely used indicators for tracking hydration.
The Science: Urine color is the most widely used method of hydration assessment due to the ease of analysis. And indeed, urine color does correlate to hydration status. As water volume decreases in a dehydrated state, the concentration of urine increases, causing the color to darken and the density of urine to increase. This is a rough estimate to measure dehydration. Other, more precise methods of urine hydration assessment include the measurement of urine specific gravity and urine osmolality, both of which can be used interchangeably to determine hydration status.
Hannah says, “Keeping track of how often you go to the bathroom (and subsequently, how light or dark your urine is) is a good way to monitor your hydration levels.”
In fact, top athletes know to keep an eye on urine color early, and often. And as the level of performance and intensity increases, it’s important to use objective measurements of hydration over subjective methods such as fatigue or thirst.
“The best way to monitor it is through looking at urine color (it should be clear or slightly yellow tinged) rather than thirst, as that is a sign that you are already dehydrated,” says Robert Herbst, World Champion powerlifter and wellness expert (19 time World Champion, 38 time National Champion, member of the AAU Strength Sports Hall of Fame). “World class athletes are very into urine.”
This is echoed by Von at Complete Tri. “The best time to hydrate is before you are thirsty. If you wait until you are parched, you are likely in the process of the dreaded bonk.”
The Science: Thirst is not generally stimulated until total body water loss reaches 1-2% of body mass. By this point of mild dehydration, performance capacity, cognitive function, and alertness are already in decline while physiological strain increases. Drinking fluids according to thirst alone does not maximize performance.
Urine analysis is not just a useful way to monitor hydration during training or recovery. For endurance athletes, ongoing monitoring is critical.
“For toilet breaks on my runs, I pee into a container, where my team checks the color of my urine to ensure I am above a certain hydration level,” says Rhys.
In addition to urine testing, comparing weight loss during intense physical activity can incorporate sweating rates into your hydration monitoring practice.
Jaonna says to “weigh yourself before and after an hour of exercise, and based on the weight lost, you drink a certain amount of fluids in ounces to replenish.”
Melissa Morris, an ISSN certified sports nutritionist and ACSM certified exercise physiologist, adds some details. “The other way is to weigh yourself before and after your sport evening or training session. Try not to use the bathroom between the before and after weighing sessions. For every pound that you lost during the training session or sports event, you need to drink at least two to three cups of water to make up for that fluid loss. Once you monitor this and there is consistency, you will know how much water to consume during your sports and exercise.”
Dominic and Sara both suggest dividing your weight (in pounds) in half to yield the number of ounces of water to drink in a day. For example, “at 150 pounds you will drink around 75 ounces per day.”
And for those who don’t like the taste of water, the pros have tips for that, too.
Nikki says, “If you struggle with water like I do, I encourage you to replenish your water in the evening with hot water, and drink two cups of hot water in the morning prior to your coffee.” And Dominic says, “A great alternative is to add lemon to your water (which is great for the digestive system) or even zero calorie flavored drops, most local stores sell, to make it more interesting.”
Sara gives a twist to these suggestions. “Something I recommend to my clients to help promote adequate hydration is a daily “Morning Margarita”! This is 12 oz of water + juice from 1/4 of a lemon or lime, and 3-7 shakes of Sea Salt. Mix and enjoy, ideally first thing in the morning before your coffee! This helps to replace hydration, sodium, and electrolytes.”
The National Athletic Trainers’ Association Position Statement highlights that “personal cues are important for individuals to gauge their hydration status. Thirst sensation, void frequency, and urine color are valuable indicators over the course of a day or between days for obtaining a relative hydration assessment.”
And studies have demonstrated personalized hydration plans (PHPs) outperform general and ad libitum approaches to proper hydration.
But there are good, general rules around hydration needs and replenishment during training and competitions.
Jack suggests, “you’ll want 16 fluid ounces per hour at least, taking sips every 20 minutes or so.”
Jeff reiterates the importance of drinking throughout an event, and specifics by the kind of activity. “With boxing and hockey, as well as other short burst activities, there’s always a stop point where you’ll have a chance to take a quick drink. It might be in between shifts or in between rounds but either way, you’ll have someone there putting a drink in your face. With an ultra run, it’s just you. You need to be conscious of your own hydration. The best way of doing this is to have some sort of stopwatch or reminder set for every 20 minutes - you MUST follow it or risk getting to the point of no return.”
If you’re interested to learn more about a new hydration measurement device, and how you can track your hydration status with ease, stay informed about Intake Health!