Emily Shields Warner, nutritionist and professional cross racer is back with her nutritional tips to help you excel in training and racing. It’s August, which means that if you are out riding, you are most likely in a significant amount of heat. Hydration is key to performance!

Consuming adequate amounts of fluid and electrolytes before, during, and after physical activity is critical for good performance. Not only is proper hydration important for physical activity but it has a great impact on almost every physiological function. On a daily basis, we require water more than any other nutrient. From an athletic perspective, proper hydration helps decrease the risk of dehydration and heat illness, maintains cardiovascular and thermoregulatory function, and improves performance during physical activity. This blog will discuss how to properly hydrate pre, during, and post physical activity.

Pre Exercise
If heavy sweating is expected, try to drink 2-3 cups of fluid 4 hours before exercise. Consume part of that fluid as a carbohydrate and electrolyte sports drink. If your urine output is still low 2 hours before exercise drink 5-12 ounces more. There is no need to over hydrate, drinking excessively does not improve performance.

During Exercise
The best way to determine if you are hydrating adequately is to periodically record your body
weight before and after activity. If you record weight loss you are not drinking enough, and if you record weight gain you may be overhydrating. Minimal weight loss (less than 1 lb or 0.5 kg) is fine. You want to avoid weighing more after exercise because drinking excess water is not beneficial. During activity, especially on a hot day, try to take sips from your water bottle at 10 to 30 minute intervals. If you are prone to dehydration, drinking on a schedule is very important. Furthermore, if you sweat profusely, drink more, if you are going on an easy spin on a cool day, drink less. If it is hot, or you are riding longer than an hour and a half, or you sweat a lot, I recommend drinking a carbohydrate and electrolyte drink mix; not just plain water. On some hard and hot training days, weighing less after you train will be inevitable. Just make sure to adequately hydrate afterwards.

Post Exercise
To rehydrate effectively post exercise try to consume 125 to 150% greater than fluid losses to compensate for sweat and urine losses.
1 kilogram of fluid = 1 liter of fluid
Consume 1.25L to 1.5L for every 1 kg body weight loss
1 kg = 2.2 pounds
Example: Pre workout weight: 61.7 kg
Post workout weight: 60.3 kg
Change in body weight: 1.4kg (multiply by 1.25 and 1.5)
Amount of fluid needed to consume: 1.75 liters to 2.1 liters

To rehydrate you must consume water in combination with foods that contain sodium, chloride and other minerals. Water turns off the thirst mechanism and turns on urine production. There are other options to drinking carbohydrate and electrolyte sports drinks. Water is fine  as long as it is consumed with food. Good examples are baked potato chips, pretzels, pickles and crackers. It is also a good idea to add extra salt to your food. Other ways to rehydrate are to consume foods with a high water content such as watermelon (great with salt on a hot day), strawberries, cantaloupe, oranges, tomatoes, and zucchini. Liquids such as milk and juice are good options as well. Try to avoid alcohol as it leads to dehydration due to its diuretic effects. Caffeine has a much milder diuretic effect and is okay to drink in moderation.

Monitoring urine output is another way to assess hydration before and after exercise. If your urine is dark colored you need to drink more, if it is light you are hydrated. However, it is important to keep in mind that some supplements, particularly vitamin B, can cause urine to be brightly colored even when adequately hydrated.

How to Determine if you are a Salty Sweater 
Electrolytes such as sodium, potassium, calcium, and magnesium are lost in urine and sweat. You lose large amounts of sodium chloride when you sweat. You may be more prone to large sodium losses than your fellow cyclists. If you can see dry, white residue on your skin or clothing after your sweat dries then you are a salty sweater and may be more likely to experience heat-related problems. So make sure to adequately hydrate before exercise, drink a carbohydrate electrolyte sports drink every 10 to 30 minutes, and properly rehydrate post exercise.

Emily received her Master’s in Nutrition from University of North Carolina at Greensboro. She is a Registered Dietitian and specializes in Sports Nutrition. She is a professional cyclist and when not racing enjoys helping people improve their athletic performance and overall health through nutrition. Emily is accepting new clients and can be reached at emily.c.shields5@gmail.com

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