Fluid Intake While Cycling

During the summer, I got in the habit of weighing myself before and after training to monitor my fluid losses.  When it was hot, I lost 35-40 oz. per hour – this seems like too much to try to drink while riding.  What are your thoughts? 

Great job with weighing yourself to monitor fluid losses – this is a great practice to determine individual fluid needs!  That said, it doesn’t mean that you need to recover all these fluids while riding, but a combo of during and after riding.  While riding, do aim for ~16-24 oz. per hour with average conditions, and up to 32 oz. per hour when it’s really hot or humid (depending also on how much you can carry comfortably).  Always try to drink at least 16 oz. per hour.  The amount of fluid that keeps you feeling hydrated, without going overboard with intake or the weight of carrying it can be trial and error, so start experimenting.  Then, make up the rest of your fluid needs immediate after your ride.

Along with fluid, try to get adequate electrolytes as well (~400-700 mg sodium, 100-300 mg potassium, 80-120 mg calcium, and 40-60 mg magnesium per hour).  The calcium and magnesium become more important with longer rides, >3 hours.

Please send us your questions for our Expert Sports Nutritionist, Kelli Jennings to “Ask the Sports Nutritionist“. Kelli Jennings is a Registered Dietitian with a passion for healthy eating, wellness, & sports nutrition. For more information go to www.apexnutritionllc.com.

  • troglobiker

    I have found this to be the hardest part of cycling to master. In 2010, I sagged out of the local century due to dehydration. In 2011, I trained very hard and my legs were in great shape for the event. Felt great through about 70-80 miles and then started feeling the nausea. That’s when it snowballs; once I feel nauseous, I no longer feel like drinking. I rode the remainder of the 109 mile route fighting the nausea and trying to take on water. I weighed 182 before the ride and 173 after!!!!

    • http://twitter.com/fuelright Kelli Jennings

      Hi troglobiker,
      Thanks for your comment.  Yes, this is much easier said than done.  With my clients, I insist that they practice good hydration in training rides so that it’s habit in a long tour or race.  So many times it seems easier to just tough it out when training, but the habits need to be formed before it really counts.  Also, I’m always surprised when athletes are advised to drink just to thirst in a long or intense ride…in my experience professional and personally, it’s too easy to forget to drink or delay it until it just becomes too late.  And then you’re draggin and/or nauseous, as you said.  Once nauseous, it’s hard to convince yourself to drink fluids, especially ones with carbs and lytes.  If you actually get sick and vomit, dehydration becomes even more of a problem.  My advise?  Drink to a schedule…no matter if your thirsty or not.  Pack the amount based on the time anticipated for the ride, and drink it up.  Over-hydration is a much less common issue than dehydration.  And, as I’m sure you realize, an 11 lb fluid loss is serious stuff!  Keep working on the good habits!  I hope this helps!  Kelli, RD