4 min read
Ninety miles into a planned 200-mile ride to Philadelphia and back, the heat started to break us. It was the hottest day of the year, with temperatures pushing past 100 degrees. We stopped at nearly every gas station for cold water and ice, but what we needed most were electrolytes. We were sweating them out faster than we could replace them, and that imbalance slowly caught up with us. Staying well-hydrated is essential for strong performance on the bike—and it’s about much more than simply avoiding dehydration. Still, plenty of myths and misunderstandings persist.
Under-hydrating does more than leave you thirsty. It has severe performance effects. “Rehydration during Endurance Exercise: Challenges, Research, Options, Methods” published in the peer-reviewed journal Nutrients in 2021 found, “virtually all researchers agree that moderate-to-severe dehydration results in greater physiologic strain and decreased aerobic exercise performance.”
But staying hydrated (or even understanding what proper hydration looks like) is not always straightforward. Myths and mistakes still abound. And they can be affecting your performance. Here are some of the most common and persistent hydration myths, how to avoid them, with tips and advice from a registered dietitian.
Myth 1: I Only Need to Focus on Hydration During a Ride
The reality: The best way to be hydrated during your ride is to start hydrated. The National Athletic Trainers’ Association suggests drinking approximately 500 to 600 ml of water or sports drink two to three hours before exercise and an additional 200 to 300 ml of water or sports drink 10 to 20 min before exercise. Taylor Brower, RD, who works with hydration supplement company Skratch Labs, stresses that your prehydrating should also include electrolytes, so you can pull from those stores as you ride. “That can look like sipping on some electrolytes beforehand or maybe not even needing to add true electrolytes, but just well salting your food,” she says.
Myth 2: What Worked for One Ride Will Work for Another
The reality: “Sweat rate is extremely variable,” Brower says. “It is going to differ depending on where you are, what altitude you’re in, what environment you’re in, how intense the activity that you’re doing is, and the duration of that activity.” Brower suggests one low-tech strategy that can help you understand your sweat rate during an activity. “Weigh yourself before and after you head out on the bike and measure what that difference is. So typically for every one pound you lose we recommend replacing that with about 16 ounces of fluid.” This simple method will help you create a tailored hydration plan as you learn how your body responds to different conditions.
Myth 3: Only Drinking Water Is Enough
The reality: As we exercise, especially on days where we sweat more, it is important to replenish the body with what your body is using and losing. “We don’t just sweat out sodium. We also are going to be losing smaller amounts of electrolytes like potassium, magnesium, and calcium. But the one that is the most detrimental to performance and is lost in the highest concentrations in our sweat is sodium,” Brower says. Brower also mentions the importance of bringing in more than just water to prevent hyponatremia. Exercise-associated hyponatremia is defined as a serum sodium level below 135 mmol/L that develops during or up to 24 hours after physical activity. Brower sums this up with, “when we are constantly sweating out water and sodium, but we’re only bringing back in water that sets us up for a situation called hyponatremia.” I typically go with about 600mg of sodium per hour on longer rides, but this is adjusted based on the effort, distance, and conditions of the ride. Everyone has different sweat rates, so play around with what will work for you. Just remember that bringing hydration fuel to replenish electrolytes on a ride is key to feeling strong through the end.
Myth 4: I Only Need to Drink When I Feel Thirst
Recently I was on a ride with someone and I mentioned I was planning to drink one of my bottles per hour. This was based on the amount of water I was planning to intake as well as electrolytes and carbohydrates in each bottle. The rider I was with said, “I’ve never thought about it that much—I just drink when I’m thirsty.” This can be problematic because it can be easy to get distracted with your cadence, effort, or even the views on a ride. Once you get dehydrated, it is hard to get out of that hole. I like to set an alarm that reminds me to drink on rides that are over three hours. My alarm is set to every 15 minutes and I drink around six to eight ounces. Try this—do the sweat rate test above from Taylor and do the math. If you did a two-hour ride and lost two pounds, that means you need to replace it with roughly 32 ounces of fluid. On a ride with similar conditions and effort you could pace your fluid intake at about four ounces every 15 minutes to make up for that loss.
For many of us, proper hydration is a small lever to pull for big improvements on a ride. Hydrating properly before, during, and after a ride will have meaningful impacts on how you feel getting up the first climb of your ride to hanging onto the group at the end. If you like to mix things up at home, or the cost of drink mixes feels cost-prohibitive, check out this story for some homemade drink mix tips!