Why Hydration Is Key to Maintain Your Muscle Mass

While lifting weights and consuming enough protein is key to growing and maintaining muscle mass, there’s more to this equation. We also need to ensure we eat enough calories, consume all macronutrients, and get enough hours of sleep. In addition, there’s one surprising habit everyone, from elite athletes to active individuals, may be neglecting when it comes to maintaining muscle mass. The good news is that it’s pretty simple to implement once you know what it is. Below, we reveal the No. 1 habit you need to start doing to maintain your muscle mass.

The #1 Habit for Muscle Maintenance

The No. 1 surprising habit you should start prioritizing to maintain muscle is staying properly hydrated. Yes, that means drinking enough water each day. (Not only reaching for your water cup when thirsty or before hitting the gym.)

Believe it or not, most Americans—approximately 75%—are chronically dehydrated each day. And hydration matters for many bodily processes. To understand why hydration is crucial to maintaining muscle mass, we spoke with two sports dietitians, Amy Goodson, M.S., RD, CSSD, LD, and Kelly Jones, MS, RD, CSSD. They explain how proper hydration is crucial for optimal body function and muscle health. 

How Does Being Hydrated Help Maintain Muscle Mass?

Water works behind the scenes in countless ways, keeping our bodies functioning optimally. “Water is essential for cellular processes, including protein synthesis, which is vital for muscle repair and growth,” says Goodson. She explains, “When you’re dehydrated, these processes can be impaired, hindering muscle recovery and growth.” 

So, even that killer workout you did yesterday won’t translate to muscle gains if you haven’t properly hydrated afterward. Goodson also highlights water’s role as a nutrient transporter, shuttling essential nutrients throughout the body, which also impacts our muscles. She says, “Water facilitates the transport of nutrients, such as amino acids and glucose, to muscle cells. Without adequate hydration, nutrient delivery to muscles can be compromised, affecting their growth and repair.” 

Dehydration not only impacts muscle repair and rebuilding but also hinders the delivery of recovery nutrients (like protein and carbs) to get to your muscles and jump-start muscle recovery. 

Water also influences how your muscles move and contract. Goodson says, “Water plays a key role in maintaining electrolyte balance, which is necessary for proper muscle contractions during exercise. Dehydration can lead to muscle cramps and decreased performance.” And no athlete wants to experience muscle cramps or a decline in performance, especially during their big game or race. 

Jones explains, “Just a 2% body fluid loss can reduce endurance capacity and energy metabolism.” For example, a 2% loss translates to roughly 3 pounds of fluid for someone who weighs 150 pounds. That may not seem like a big deal, but it can hamper how long you can ultimately run, swim or cycle. This is because dehydration disrupts the delivery of nutrients to muscles, which is crucial for sustained activity. Jones also says that slightly higher losses in fluid can also impact your strength, intensity and even mental acuity. This can translate to lifting lighter weights, finishing fewer reps or cutting workouts short, which can obstruct your ability to build and maintain muscle mass. 

Tips for Staying Properly Hydrated

Jones and Goodson recommend following these steps to stay hydrated and help you maintain your muscle mass as you age:

• Hydrate all day long: Start your day hydrated by drinking a glass of water as soon as you wake up, to rehydrate after sleep.
• Set water break reminders: “Having fluid goals or setting reminders with fluid apps may be helpful for some people who are easily distracted by work or their to-do list, and therefore wind up in a fluid deficit by the time they realize they are thirsty,” says Jones.
• Carry a water bottle with you wherever you go: Make it a habit to take a water bottle with you wherever you go to stay on top of your hydration goals. 
• Find out how much water you need: A quick and easy way Goodson recommends is taking your body weight in pounds and dividing it in half. “Then drink that many ounces of fluid for overall hydration.” On days you are physically active, make sure you replace the fluid you’ve lost as well. Replace every pound lost during physical activity with 16 to 24 ounces of fluid.
• Hydrate before, during and after exercise: Goodson recommends hydrating with at least 16 to 20 ounces of fluid before your workout, 5 to 10 ounces every 20 minutes during activity, and at least 16 ounces for every pound lost during exercise post-workout. 
• Water is best, but don’t forget about other options too: “Water is important, but flavored waters, milk, smoothies, sports drinks all contribute to overall hydration,” says Goodson. Foods high in water, such as watermelon, oranges, cucumbers and celery, can also count toward your total fluid intake and help keep muscles well hydrated.
• Your urine can tell you a lot about how hydrated you are: Goodson explains, “Clear to pale yellow urine generally indicates adequate hydration, while darker urine may signal dehydration.” Poor output or not peeing every 3 to 4 hours are two other signals it’s time to rehydrate.

The Bottom Line

Staying adequately hydrated is a crucial component of maintaining muscle mass. Get in the habit of carrying a water bottle with you, setting water reminders and incorporating water-rich foods and other beverages like milk, electrolyte drinks and juices into your diet. Additionally, focusing on eating enough calories, consuming all macronutrients, getting enough sleep and engaging in regular exercise are all crucial for maintaining and building muscle mass.