1. How much water should I drink while exercising vs not exercising?

When not exercising: 

•  About 2 liters (8 cups) per day +  water that comes from eating fruits and vegetables (usually about 1L)

When exercising:

• 0.5-1 liter (1-4 cups) of water per hour of physical activity
• 0.5-1 liter (1-4 cups) of water in the hour afterwards
• If exercising hard, aim for about 6L total for the day.

•  For every kilogram of bodyweight, drink 30-40mL of water
•  Ex: If you weigh 200 lbs (90 kg), you would need 2.7-3.6L ( 90-120 oz)

Consider that you will need more water if you:

• Are in warmer temperatures
• In higher altitudes
• In drier climates
• Have recently drank alcohol
• Have recently eaten salty foods

2. Should I add electrolytes to my water?

If you are sweating a significant amount while working out, you should most likely be adding electrolytes to your water. This especially goes for those of you who could basically wring out your shirt with sweat when you’re done working out! This is an important part of hydration and performance. 

When we sweat,  we lose electrolytes. Maintaining the balance between water and electrolytes in our bodies is super important. So if you are replenishing lost water but not electrolytes, this balance will be disrupted.

We use electrolytes for every process taking place inside our bodies, so it is important that we replace what is lost.

My favorite electrolyte powder is Wave by HidrateSpark in the strawberry flavor.

DripDrop is also a great option if you want something with carbs in it as well.

Whichever electrolyte supplement you use, make sure you always dilute the solution to <10% concentration to avoid GI upset.

3. How do I know if I am drinking enough water?

If you are exercising and not replacing the water you are losing through sweat you may experience any of the following symptoms from least to most severe, as you become more dehydrated:

• reduced aerobic endurance
• reduced muscular endurance
• reduced muscle strength
• reduced motor skills
• heat cramps
• heat exhaustion
• fatigue
• reduced mental capacity
• heatstroke
• coma
• death

As an endurance athlete, you should be most concerned about how dehydration has a direct effect on the efficiency of your heart rate.

Losing water through sweating means a lower blood volume since blood plasma is mostly made up of water. This means the heart needs to work harder to pump blood throughout the body. Heart rate must increase in order to deliver the same cardiac output. In case you were wondering…this is called “cardiovascular drift”.

For endurance athletes, efficiency in heart rate has a big impact on performance.

STAYING HYDRATED= OPTIMAL PERFORMANCE

In general though, urine color is a standard indicator of how well hydrated you are. Aim for light-colored and clear.

Check out this infographic:

Infographic courtesy of Healthdirect Australia.

4. What should I know about the effects of alcohol and caffeine on hydration and performance?

Since caffeine is a diuretic, you may be wondering if taking it before exercise would cause dehydration. Research shows that this only occurs if taken in high amounts.

Drinking a cup of coffee or taking the appropriate amount of caffeine before activity can actually improve performance.

You can read more about what the appropriate amount of caffeine is, and how it affects performance in my blog article, Caffeine and Athletic Performance.

Alcohol on the other hand, has no positive effect on performance and definitely contributes to more rapid dehydration.

Alcohol suppresses the release of anti-diuretic hormone (ADH), which means you will produce more urine.

One drink can increase urine output by 150mL! 

…… Ergo, DEHYDRATION.

These effects of dehydration go well into the next day, hence, a hangover. I doubt anyone can say they perform better with a hangover.

Also, you may notice you are moving slower and have less energy, since your liver is too busy breaking down the alcohol instead of producing glucose. Less glucose = lower blood sugar and less energy.