Ultramarathon Nutrition and Hydration

Note to the reader: I added and updated version of this post here.

When I get asked about training for an ultramarathon, nutrition is almost always the first thing I mention. The longer the race (in distance and time), and the more extreme the conditions, the more important this topic becomes. It is hard for me to imagine someone moving to the ultra distance -- particularly in any race lasting more than 5 or 6 hours -- without having at least a rudimentary plan. Ultramarathons are sometimes described as eating contests with a little running mixed in! And if you plan to do more than "just finish" at the ultra distance, then nutrition is a key success factor. Here is a step-by-step plan to get you started on deciding how to approach a nutrition plan.

Step 1: Determine what your needs are

The starting point for this process is to determine how many calories you need to consume. From this chart, you can estimate the number of calories you'll need to consume based on the distance you are running. This is obviously just a starting point from which to experiment. In general, the faster you run and the shorter the race, the more you'll need to replace lost carbohydrates. While there is no absolute rule, I recommend considering fat and protein as part of your macro nutrients by the 50 mile distance, and definitely by the 100 mile distance.

Once you have an idea how much you need to consume, the tricky part is deciding on a plan to get to that number and later learning how to improvise when things change. Calories will come from primarily two sources: what you eat and what you drink.  

Step 2: Drinking

There are a variety of beverages out there and which one you pick is all about personal preference. Some runners prefer only to drink water, in which case you can skip to step 3 because all your calories come from sources other than drink. If you chose to use an electrolyte beverage/sports drink, you can choose to pick one that you love or you can just figure out what the race is serving and attempt to train with that. Figure out how many calories come from your selected beverage per serving and per hour.  For example, I prefer GU Roctane Drink, which I know is about 250 calories (59 gm of carbs) per handheld. And, through experimentation, I know that I can consume roughly one handheld per hour under average weather conditions. What's more, I know that a 70 oz hydration pack is roughly 750 calories and a little more than 3 hours of fluid under normal conditions.

Step 3: Eating

Once you have decided on a fluid plan, you should have rough idea of the calorie deficit you need to make up. The common source of carb food is a gel. The trick is that not all gels are created equal. There are three types of sugar and your body handles each one differently. I am currently experimenting with Vi Endurance Energy Gels, GU Roctane Gels, and Vitalyte Chia Gels. All but the Vitalytes give you 100 calories per gel. Each has a different mixture of sugar sources (and a little fat and electrolytes).

There is one primary drawback to gels: you have to chase them with 6 - 8 ounces of water! Gels are dehydrated sugar and are hard on your stomach. Your body needs fluids or it will have to send additional blood flow to your stomach which can lead to GI issues and/or dehydration. If you are not a runner that likes to drink a ton, it can be difficult to find the trade-off between drinking fluids for calories and drinking fluids to chase gels. In other words, if you don't drink more than 20 ounces per hour, then you have to decide how many of those ounces are calorie providing beverage and how many are pure water chasing down gels. Try different things out because you are an experiment of one.

Of course you can try other sources of carbs as well. There are many products on the market that I have tried. Perpetuem is marketed as an ultra endurance product. It is a soy-based drink, so it is kind of grainy when consumed, but it is calories dense with mostly non-sugar carbs and some protein and fat. Perpetuem is what I nursed through a major bonk at San Juan Solstice 50. Another option that I have tried is hammer bars. Like Perpetum, they have some additional sources of food like fat and protein.

Keeping track, I determined in step 1 that I need about 360 calories (90 gm of carbs) per hour to support my 190 lb body during an ultramarathon. (Note that this is just carbs, I try for closer to 400 calories per hour to incorporate a little fat and protein in longer races). In step 2, I figured that my favorite drink will give me roughly 250 calories (59 gms of carbs) per hour. That leaves me roughly a 110 calorie deficit per hour. If I am successful in consuming at least one gel an hour, that should put me pretty close my desired carbs per hour.

Other Considerations

I recommend starting the race with at least 300 - 500 calories of breakfast an hour or so before the race. A couple of good options are a packet of Perpetuem and/or a packet of PocketFuel. If you can get a good breakfast in you, then you can probably go light on the nutrition for the first hour of the run.

I recommend eating some real food near lunch and/or the halfway point of the race. This should help satiate hunger (carbs don't serve that function) and may even settle your stomach a bit. A good option would once again be PocketFuel. They are calorie dense with fat and protein and will "sit" in your stomach to satiate hunger and provide long-lasting energy. You can also eat sandwiches or other race provided options for this.

Post race I recommend following a nutrient timing approach where you replenish carbs immediately following a race or workout and then eat protein and fat as you get further from the workout.

Electrolytes

I highly recommend S!Caps. While both are possible, there is generally a more pressing issue with hyponatremia than dehydration at the ultra distance. All things being equal, the slower pace allows you to drink more. But without enough electrolytes, you cannot properly process all those fluids. Even the best products don't usually have enough sodium in them to sustain you in an ultra. Electrolyte calculations can get a little complicated because everything you consume (drinks, gels, bars, etc..) have some electrolytes in them. And that can be a lot to think about on race day. The good news is that it is hard to overdo electrolytes. The safest place to start on this journey is to drink to thirst and use one S!Cap per hour in moderate conditions and two S!Caps per hour in hot conditions. But, beware of any products you eat or drink that provide substantial sources of electrolytes.

Putting it all together

In the past I have tried to stay away from gels, primarily because they don't have fat and protein. I think I was overestimating the value of fat and protein in a 10 hour race. The other reason I have tended to avoid gels is that they are hard on my stomach, probably due to a lack of water. My LT100 plan was for lots of fat and protein from PocketFuel and most of my carbs from GU Roctane Drink. And while I think that worked well, if I could do it gain today, then I would likely try to increase my carb intake even more (and decrease my fat and protein).

All of this planning is just a guiding post to keep me on target. On race day lots of things change. I could alternate back and forth between the several of my favorite products. And some decisions will depend on crew and drop bag scenarios. I will be more likely drink a product like Perpetuem early in the day or late at night when it is cool because I find that the soy-based fluid is easier to drink in cool conditions. As it warms up, I prefer to drink a more traditional electrolyte beverage. And once in awhile I may have a hammer bar instead of a gel. But the one thing I have to keep in mind is that I am always striving for the combination of products that gets me to 360 calories. And I train for several scenarios so that I am prepared on race day.

A couple of disclosures in closing: the first is that I am not a nutritionist. If you have real concerns about specific products and your individual needs, I suggest you consult someone who is a nutritionist. Second, you are an experiment of one. All of this information is just a starting point for you to begin as you train. I recommend trying several scenarios before race day to get a mix that works for you. I don't think I have quite achieved that optimal level of nutrition yet. And I have done about half a dozen different plans so far!