A friend asked me yesterday about what I bring with me on a long run in terms of food and drink. I’m in my third go round of marathon training and have learned quite a lot over the years about what works for me and my body. There are general rules that apply to everyone when it comes to refueling needs over longer runs, but the specifics definitely vary from person to person and should be experimented with over time.

First off, most anyone in decent shape can perform an endurance activity for an hour to around an hour and fifteen minutes without needing to refuel. Our body’s glycogen reserves, if sufficiently topped off pre-exercise, provide enough fuel for that period of time. However, factors such as intensity, heat, and fitness level affect how much liquid and fuel each of us needs for any given workout. On a hot day, for instance, our sweat rate is much higher and then our needs for fluid are greater as we dehydrate more quickly. Also, if we want to finish the workout or race strong, we should certainly take in fluids and fuel before we begin to approach dehydration and glycogen depletion. Recovery will also come quicker if we don’t nearly empty our glycogen reserves every time we head out on a tough long run.

The challenge is to assess environmental conditions, know what we plan to do in the particular workout, and know the current requirements of our bodies. For instance, if I were about to head out for a long tempo run that was going to take me more than an hour when it’s 80° outside, I’d be sure to have a bottle of sports drink with me and maybe even a few shot blocks or an energy gel. I’ve taken a liking to Clif Shot Bloks for my longer workouts and races. They’re fun to eat— sort of like gummy bears, they taste pretty good, and they can be eaten in smaller increments unlike energy gels.

I need to have a sports drink instead of only water on the longer workouts as they provide needed sugars and electrolytes. Water alone will stave off dehydration, but it won’t prevent someone from hitting the wall when their glycogen is used up. We also have to watch out for hyponatremia, a potentially life-threatening condition caused by drinking too much, even when drinking during exercise. Just because we’re running and burning calories doesn’t mean we can drink non-stop. For me, drinking a couple swallows every 10 to 20 minutes seems to work well during my long runs and races.

All that said, it’s never easy to pin down exactly what I’ll need on a sustained long run, especially for something over 15 miles. Some days no matter how prepared I feel, I still might struggle for one reason or another and that reason may not be hydration or nutrition related at all. In the end I like to head into a long run prepared. I like having a little more than I will need with me, or at least a way to get to what I’ll need if something goes wrong. I’ve taken to doing my long runs with a hip pack that holds two bottles. In one bottle I usually have full-strength Gatorade, in the other I have water or diluted Gatorade. In the pocket I’ll have a package of shot bloks and often some real food as well. The 2-bottle hip pack is a bit cumbersome sometimes, so if running a loop is an option for my long run I will sometimes stash extra supplies in a central location, like my car, where I can make a pit stop to refuel after completing a loop if I need to. That way I can get by with a lighter pack that holds only one bottle.

I find that after being out on a long run for more than a couple hours I start to crave real food. Drinking the same sugary Gatorade and eating the same shot bloks for hours on end gets old and is sometimes nauseating. What has worked for me to tackle that real food craving are fig bars, raisins, granola bars, clif bars and even candy bars— all carbs that are quickly and rather easily converted to glucose. Carbohydrates are what our bodies need the most to keep going during an endurance activity as they’re easily broken down into fuel.

One more note about the shot bloks: I exclusively use the margarita flavor as they have 3 times the sodium of the others. For me, this is a necessity as I’m an above-average salty sweater and I need to replenish that sodium, a necessary electrolyte, in order to ward off muscle cramps. This is something I learned during the second half of my first marathon as the temps had warmed up and I had been out there sweating and pushing myself hard for over 2 hours and suddenly my leg muscles began to cramp…OUCH!

Saturday I have a 22-miler planned. High temperature for the day is predicted to be 73, which is much warmer than it’s been here all spring. Also, I am not adapted to running in any kind of heat as it’s been mostly in the 40′s and 50′s lately. So, I’ll be sure to head out early enough to hopefully enjoy some 50′s and 60′s, which shouldn’t melt me into a gooey mess along the way somewhere. I’m thinking I might try doing 3 loops of approximately 7-miles and that way I will be able to get by with my one-bottle pack. In the bottle I’ll have half-strength Gatorade and I’ll have a package of shot bloks in the pocket. I don’t want to lug my big pack with me for 22 miles. I’ll stop back at the car after each loop and perhaps have a little snack, maybe have a couple swigs of the chia fresca (delicious conconction of chia seeds, water, fruit juice, and lime) I’ll have waiting for me there.

There’s some more helpful info about hydrating and refueling in these articles:

• Runner’s World, Carbs on the Run: http://www.runnersworld.com/article/0,7120,s6-242-301–12826-0,00.html
• Running Times’ Guide to Sports Drinks and Gels: http://runningtimes.com/Article.aspx?ArticleID=6677
• How Much Should You Drink During a Marathon (good info about hyponatremia): http://www.runnersworld.com/article/0,7120,s6-242-302–8785-1-3-2,00.html