You’ve been told throughout your life how important it is to drink enough water and stay properly hydrated, but have you ever stopped and really considered how much water you actually drink on a daily basis or why you need to drink so much water each day?
We’ve all been told at one time or another to drink at least eight 8 oz. glasses of water per day, but is this number backed by any science or is it just an old wives’ tale? What if you’re consuming water-rich foods like fruits and vegetables? Do those count towards your daily water intake totals?
Chances are you’ve pondered these questions and several others in regards to drinking water and maintaining your hydration levels. Ahead, we’ve got the basics on hydration and how (and why!) proper hydration is essential for optimal performance.
Grab your favorite sipping glass and let’s get going!
Before covering why hydration is important to performance, we first need to answer the question of how much water you need on a daily basis.
The answer isn’t eight, 8 oz. glasses of water (if things were only that simple). The truth is, every individual is different. An ultra-marathoner’s water needs are very different from the sedentary grandma knitting in her cottage. Moreover, each individual’s water needs are impacted by their age, gender, environment, activity level, and any previous/current health issues.
The human body is composed of approximately 60% water.<1> So, you know that water is pretty crucial based off that alone. The human body can survive for a few of days without water, but not much beyond that. Simply put, without water your body shuts down -- metabolic processes cease, core temperature increases, cognitive function decline, muscles don’t fire as they should, and that’s not even the worst of it!
Here’s all the different ways your body uses (and loses) water each day:
- Urination / excretion
- Evaporation from the lungs and skin and lungs (respiration and perspiration)
- Beverages (water, coffee, tea, milk, etc.)
- Food (vegetables, fruit, etc.)
- Metabolic processes (oxidation of carbohydrates, protein, and fats)
Water’s Roles in the Body
Water is absolutely essential, if you haven’t figured that out by now, here’s a list of several different bodily processes requiring water:
- Regulation of core temperature
- Production of neurotransmitters
- Oxygen delivery for the body
- Shock absorber for brain and spinal cord
- Joint lubrication
The list is much more extensive than this, but the previous topics serve to highly just how crucial water is for just about everything that goes on in your body.
Now, let’s see water’s role on performance!
Hydration and Performance
Water is critical to overall health, but it’s even more important to your performance as an athlete. In fact, even as little as a 2% drop in hydration can severely hinder performance.<2> Your performance isn’t all that suffers when running low on water, being dehydrated also reduces your focus, concentration, strength, and power!<3,4> Some research even shows that losing larger amounts of water (~ 5% of body weight) can decrease work capacity by as much as 30%!
There’s several reasons dehydration adversely affects performance:
- Elevated core temperature.<5,6>
- Decreased blood flow to skin (reducing sweating and heat dissipation)
- Reduced plasma blood volume (leading to lower stroke volume and increased heart rate)
There’s more though -- dehydration also hinders cognitive function by decreasing focus, coordination, memory, attention and response time. You’ll also become fatigued that much faster and more sensitive to pain.<6>
In other words, dehydration is the last thing a high-performing athlete wants while training or in the midst of competition.
Proper Hydration for Athletes
We still haven’t answered the question of how much water you need on a daily basis, and that’s because there is no “set in stone”, one size fits all answer for every individual. However, the American College of Sports Medicine’s has created a set of Fluid Replacement Guidelines for those involved in intense training:
- Pre Workout = 14 - 22oz of water 2 hours prior to exercise
- Intra Workout = 6 - 12oz every 15 - 20 mins of exercise
- Post Workout = 16 - 24oz of water / sports drink for every pound of weight lost during exercise
The last factor to account for when assessing hydration needs is what climate you’re training in. Water needs are very different for an athlete training in an air-conditioned environment versus one training in the mid-July heat.
Exercising outdoors in the heat increases sweat production and evaporation, which means you’ll need even more water (as well as some electrolytes) to replace what was lost via sweating. The same holds true for training outdoor in very cold environments.
Even though you’re not sweating as much as when in the heat, your body is still going through its water reserves like crazy trying to maintain your core temperature and power your mind and muscles through training. Plus, training in the cold might increase urine output and increase the respiratory loss of fluids.
Bottom line, even if you’re not that thirsty, make sure you’re getting enough water if you want to perform at your best!
Water is absolutely essential to all areas of daily life, including your performance. Make sure to drink enough pre, during, and post workout so that you’re not bonking during your workouts or dehydrated for the next day’s intense bout of exercise. Use the guidelines here as a starting point to assessing your hydration needs and feel free to increase based on your training volume and conditions!
Have a hard time drinking all that water? Put some Steel Fuel™ All-In-One BCAA + Hydration Formula in your water to sip on throughout the day as a fantastic alternative to sugary sports drinks or juices. Steel Fuel™ also features a Hydration Matrix to keep you preforming your best! This matrix includes: Taurine, Magnesium Glycinate Glutamine Chelate, Raw Coconut Water Powder, Sodium Chloride and potassium Citrate.
- Barr SI. Effects of dehydration on exercise performance. Can J Appl Physiol. 1999;24(2):164-172.
- Judelson DA, Maresh CM, Farrell MJ, et al. Effect of hydration state on strength, power, and resistance exercise performance. Med Sci Sports Exerc. 2007;39(10):1817-1824. doi:10.1249/mss.0b013e3180de5f22.
- Judelson DA, Maresh CM, Anderson JM, et al. Hydration and muscular performance: does fluid balance affect strength, power and high-intensity endurance? Sports Med. 2007;37(10):907-921.
- José G-A, Mora-Rodríguez R, Below PR, Coyle EF. Dehydration markedly impairs cardiovascular function in hyperthermic endurance athletes during exercise. J Appl Physiol. 1997;82(4):1229 LP-1236.
- Ogino Y, Kakeda T, Nakamura K, Saito S. Dehydration Enhances Pain-Evoked Activation in the Human Brain Compared with Rehydration. Anesth Analg. 2014;118(6).