How to Nail Down a Fueling Strategy

The summer race season is upon us, which usually means plenty of heat and loss of fluids!  Whether you are running a marathon, riding in a charity century ride, racing in a criterium, or even a triathlon, it is critical to have a solid fueling and hydration plan that will work in your race or event. Nothing is worse than wanting to make that final attack or make a final push to finish strong and find that you have nothing left in the tank!

Finding the right mix of fluids and fuel can be challenging for several reasons. For one, there are tons of sports nutrition products on the market so it can be a bit overwhelming trying to find the “right one.” (We’ll save that topic for another day.) Another is that it takes some trial and error to find the right amount of fluid and calories that work for you. But with a little planning and practice, you can nail that fueling strategy for your event.

Here are some tips to get you there:

1) Know your fluid loss rate. To estimate this, weigh yourself (no clothes) right before your workout. Then weigh yourself immediately after (no clothes). Subtract the before from after and then add in one pound for every 16oz of fluid consumed. The number you end up with is how many pounds of fluid you lost. Multiply that by 16oz (approximate volume of 1 pound of fluid) and then divide that by the duration of your workout (in hours). Now you know approximately how much fluid you lose per hour. Your loss rate will change depending on weather conditions, as we tend to sweat more when it is warmer out, so make sure you log the temperature when you do this test, and if possible, mimic race conditions. During your workouts and races, aim to replace at least 80% of your fluid loss.

For the formula types:
Estimated fluid loss rate = [(wt. after(lbs) - wt. before(lbs) + (oz consumed/16oz)) * 16oz ]/workout duration (hr)


2) Dial in the calories. Trial and error will get you to your number. Start on the the low end, say 100-150 calories an hour, and see how you do. If you bonk, eat more (bring extra with you!) Try adding another 50 calories per hour if you feel you need more. Keep the calorie intake steady to help keep the blood sugar more stable. Keep in mind that the fewer calories you consume, the less chance for GI distress. (See my previous post on metabolic efficiency.)  That’s also why we start at the low end - it’s easier to eat a little more, but if you eat too much, it can be quite uncomfortable. And remember you can get calories from both solid, gel, and liquid sources.

3) Practice your fueling/hydration plans at race efforts and conditions. That energy bar might sit well when you are cruising at a moderate aerobic pace, but once you dial up the intensity, it might not be as pleasant. Also, make sure you finish these key workouts strong! You should feel fatigued from the effort, but not depleted from dehydration and low blood sugar!

Experiment in your training, keep a log of what you do in TrainingPeaks, and practice in your less important races and race-simulation training sessions. Do this and you will have everything dialed in for the most important races!

Here’s an example of how you can track these details in TrainingPeaks:
 

1) You can use daily metrics to record your weight and fluid intake at different times:

 

2) Calories consumed can be tracked using nutrition

And all this data can be viewed on one screen if you select ‘View Day’ in the calendar mode:

 

Simply expand each section to view the full report.

Happy training, tracking, and racing!

Nicole Drummer is a USA Cycling and USA Triathlon Certified Coach. She is the author of The Triathlete’s Guide to Race Week and coaches endurance sport athletes through her coaching company, NEO Endurance Sports & Fitness. Learn how Nicole can help you achieve your endurance sport goals at http://neoendurancesports.com and http://neoendurance.blogspot.com. You can also find Coach Nicole on facebook, twitter or contact her via email at nicole@neoendurancesports.com.

Comments

[KenZ]

Good, important post, but I think some of these answers should be qualified. For instance on fluid, the recommendation is to "replace at least 80% of your fluid loss." That's a fine strategy without qualification if you're doing, say, up to 4-5 hours of exercise. But if you're doing an ultramarathon of 9+ hours, you try to replace 100% of your loss, don't add electrolytes (which aren't mentioned in this article), you're well on your way to a DNF and, while unlikely in something only 9-12 hours, possibly kidney failure.

My qualification of the article would be: This is great advice for nutrition newbies up to 4 hours. Over 4 hours, you need to do in depth research, NOT over hydrate, and absolutely ensure you're taking electrolyte balancing into consideration. "Replace at least 80% of your fluid loss" seems to be an invitation to hyponutremia for those who don't understand the balance.

[I-Run-42.2K]

I agree with this comment; not only do you have to be careful with hydration and fuel; you have to also be careful of
over-hydration which can actually be lethal. It's about balance. It's better to hit the wall and "stop" than passing out when your body fluids and electolytes are too much out of balance!