It's HOT! Tricks to staying hydrated for optimal performance and recovery

Feeling the heat this summer?! It’s hot AND humid in the South. If you are out in the heat, whether it’s 1-3+ hour bike rides or runs, walking the dog, or gardening, it is important to stay hydrated to make sure you are equipped to deal with the heat and humidity.

Your everyday beverage consumption sets the tone.

First, drink water. There are several guidelines and opinions about how much water you should drink per day. When in doubt, drink when thirsty. Thirst is the body’s way of letting you know it needs water (duh).

Second, also, drink water. Water is the best form of hydration throughout the day. If you have coffee, soda, and energy drink or other caffeinated beverage, be aware that caffeine is a diuretic and might contribute to dehydration. Alcohol is also a diuretic, so be aware if you have a few drinks at night or after a run or bike ride, remember to also drink water. A friend once told me a trick, if you are going out with friends and will indulge in a couple adult beverages, have 1 glass of water between alcoholic beverages. This will help with hydration and slow down your alcohol consumption (they are just empty calories anyways!). As far as beverage consumption throughout the day, water is best. If that is a challenge for you, try naturally flavored or sparkling water.

Staying hydrated before, during, and after exercise

Hydration is a key factor in performance and recovery. Improper hydration can lead to cramping during a workout, fluid imbalances, and have lasting effects after a workout. Intensity, duration, and location can help you determine what to drink during and after a workout for optimal performance and recovery.

Water consumption may suffice short workouts lasting less than an hour. If the workout is outdoors and you are a heavy sweater, consider a sports drink during and/or after to replenish electrolyte (sodium and potassium) loss. During prolonged, intense exercise, it becomes more important to replace the fluid and minerals lost in sweat. The appropriate amount for rehydration will depend on factors such as the level and duration of exertion.

Before Exercise:


Here are the guidelines: In the 2-3 hours before your workout or event, drink 16 oz of water, that is just 2 cups. 1 hour prior to exercise, drink 8 oz, or 1 cup of water. Consider these guidelines a starting point for your pre-workout hydration. There are several opinions about sports nutrition, but you have to find what works best for you. Keep that in mind as you continue reading.

During exercise:

Why does hydration matter? Water and fluid plays a role in plasma volume. Plasma is a component of blood and actually makes up about 55% of our blood volume. When water is lost during exercise (sweating), plasma volume is also reduced. A reduction in plasma volume is related to decreased performance. For instance, reduced plasma volume compromises the body’s maximal oxygen uptake (VO2max), or the ability of oxygen to be taken from lungs and transported to muscles to produce energy. Reduced plasma volume also contributes to body temperature as well as cardiac drift, or the increase in HR during prolonged exercise without an increase in intensity. Just a liter of water loss contributes to decreases in performance. Therefore, hydration can make or break a workout or event, particularly in high heat and humidity.

The following are guidelines to experiment with. Let these serve as a starting point as everyone is different. Your habitual diet, hydration status, fitness level, previous week of workouts, sweat rate, water and sport nutrition likes/dislikes, and digestion, among others are factors that contribute to nutrition intake during a workout.

  • Drink a few big gulps (or approx. 200ml) every 10-15 min which is about 1-16 oz bottle, or 1/2 L/hr

  • Start drinking early in the activity

  • Avoid drinking large doses of caffeine

  • Practice drinking during training

  • Spread fluid and carbohydrate intake during ride

Post exercise fluid intake:

Dehydration is much more than being thirsty or needing water. It happens at the cellular level. In fact, a dehydrated cell is catabolic – favors breakdown of glycogen and protein. A hydrated cell is anabolic and well suited for glycogen restoration and protein synthesis and repair. (Glycogen is the storage form of energy. It is important to replenish after a tough and/or long workout). Therefore, a hydrated cell promotes recovery while a dehydrated cell will prolong recovery and may hinder your next workout.  Begin rehydrating immediately and spread fluid intake over time. Add sodium to increase fluid retention by kidneys. For example, consume electrolyte drink. If you don’t want the added sugar after a workout, try Power Aid Zero or a low sugar drink.

To avoid lasting dehydration, here are guidelines to experiment with. Tweak to see what works for you:

  • Consume 1.5L for every kg body weight lost

  • Fluid should contain 400-1000 mg sodium and 120-225 mg potassium per Liter lost

  • Drinking water with a meal will replenish lost fluid and electrolytes

  • Replace carbohydrate 1g/kg body weight – a recovery drink or bar with 6-7% (14-15g CHO/8oz) is ideal for replacing carbohydrate during exercise. Higher carbohydrate concentration can be used after.

  • Electrolytes: sodium and potassium are the main 2

What about sports drinks?

Sports drinks such as Gatorade, Powerade, Heed, and Skratch to name a few are specifically engineered for pre-, during-, and post-exercise consumption. They are designed to rehydrate, provide energy and replenish the body’s electrolytes, especially sodium, which is lost through sweating. Sports drinks will reduce the risk of fluid-electrolyte imbalances that can occur after a long workout or race with a high level of sweating. If you are exercising for 1 hour or longer, particularly at moderate- to high intensities, you will benefit from a sports drink. Many sports drinks also contain carbohydrates – the body’s main source of energy for higher-intensity activities.

If exercising less than 1 hour, especially indoors with air conditioning, water will likely suffice. If your workout is longer than 1 hour, consuming a few gulps of a sports drink every 15-20 minutes can help maintain energy and electrolyte levels, and sustain performance. This translates to approximately 1 bottle per hour. Again, think of this information as a starting point or guide. If that does not work for you (for example, the sugar content causes GI distress), try diluting or dialing up the concentration of your drink.

I don't sweat, I glisten. Like a pig!

Are you a heavy or salty sweater? If you struggle with cramping during exercise, consider determining your water loss during exercise. Simply weigh yourself before and after your workout (in the nude if possible) and subtract your post-ride weight from your pre-ride weight. If you lose more than 2 pounds, try a post-ride recovery drink with electrolytes along with water every hour to replenish what you have lost. Get in the habit of “weighing in” and “weighing out” before and after a workout to keep an eye on your fluid loss.

You can take it a step further and calculate your sweat rate. To do this, weight before and after your workout and keep track of how many bottles you drink during your workout. Then follow these simple steps. You might need a calculator.

  1. Convert your pre- and post-workout weight to kilograms: ___ lbs X 0.454 = ____ kg

    • For example: Pre-ride weight = 120lbs X 0.454=­54.48kg Post ride weight= 117lbs X 0.454= 53.12kg

  2. Subtract the post-ride weight (in kg) from the pre-ride weight in (kg)

    • Pre-ride weight (kg) – post-rid weight (kg) = weight lost during ride

    • For example: 54.48-53.12 = 1.36kg

  3. Add the amount of water (in liters).

    • Weight lost during ride + fluid intake (L) = gross water loss

    • For example: 2 Liters of water were consumed. 1.36kg+2L = 3.26L

  4. Determine your Sweat Rate: Divide the gross water loss by time.

    • For example: duration of activity was 3 hours. 3.26L/3 hours = 1.12L/hour

In Short:

        Pre-race weight (kg) = 54.48

        Post-race weight (kg) = 53.12

        Fluid intake (L) = 2

        Time (hours) = 3

        Sweat rate (L/hr) = [(54.48-53.12)+2]/3=~1.12 L/hr

If you track sweat rate with the weather conditions, you can estimate how much fluid you need to consume based on conditions such as temperature, duration, and intensity.

Another method (albeit not as scientific) to assess if you are consuming enough fluid is the color and frequency of urination.  If your urine is clear and you are urinating frequently, you should be close to maintaining adequate hydration levels.  However, be aware that although you are drinking a lot of water and your urine is clear or light in color, water retention may not be adequate. 

Need more help with hydration or nutrition?

If you struggle with cramping or just want to really dial in your pre-, during-, and post-workout hydration, I suggest you try a sweat test (Fagan Sports Medicine is great if you are in the Birmingham, AL area). A sweat test will inform you of electrolyte and water loss in units per hour to know what and how much to take in per hour.

If you have a performance or weight loss goal, want to really dial in your pre-, during-, and post-workout nutrition, or become more healthy and consistent with your eating habits, schedule a consult! With a nutrition consult, we will break down your day-to-day diet, your pre-, during-, and post-workout nutrition, set goals, and make a plan to meet your goals.