How to Fuel for Your First Marathon

Q I’m training for my first marathon, and I’m struggling to get my 32- to 35-kilometre training runs completed. I run for 24 kilometres and have to make myself keep going. I haven’t done more than 30 kilometres on the training runs. I ran 2486 kilometres last year, have done four half-marathons, and ran 65+ kilometres a week – just not 32+ kilometres in a day.

My fuelling strategy is this: On the 25-kilometre and less runs, I drink water and that’s it. During longer runs, I eat energy chews. I take about four with me and eat them while I run. On half-marathon race days I’ve taken GUs, and they seem to work for me. During last week’s training run, I was supposed to cover 34 kilometres, but I was so tired I stopped at a store and ate a banana and granola bar and some Powerade. I felt better, but that was about 18.5 kilometres in, and I had to call for a ride home at kilometre 24. In the past I’ve avoided eating too much because it makes me feel slow and sluggish or causes emergency bathroom breaks. Please help!


A Many first-time marathoners – and even seasoned marathoners – struggle with nailing down what to eat to make it through long training runs. Some runners skip long run fuel altogether and don’t even give it a thought until race day.

You’re smart to be thinking about it now and realising that hitting the wall during your long runs is probably a result of not enough energy in the tank. It’s important to nail down nutrition during training runs because whatever works for you during these runs is what should work for you on race day. Determining your best strategy can take some trial and error. You may need to try out different forms of fuel – gels, blocks, beans, chews, bars, and even real food – are options. You may need to try different brands, various flavours, and various amounts before you hone in on your perfect fuelling plan (so it’s best to start experimentation early), and once you find something that works for you, stick with it. It’s easy to forget what exactly worked for you out on the road so remember to write down your fuelling regimen in your training journal. That way, the next time a long run is scheduled, there will be no question of what did or didn’t work for you.

To make it through a long run or a marathon, what you eat before and during the run is crucial. Your meals in the hours before the run will supply your muscles with glycogen and will essentially top your your fuel tank. During the run, this tank will be depleted, and that’s why it’s necessary to add in fuel as you go along. Most experts recommend consuming between 30-60 grams of carbohydrate an hour. Personally, I aim for 45 grams of carb each hour, and I recommend that the athletes I work with do the same. Right now, it looks like you are consuming well below this target, and I suspect that’s why you are hitting the wall early in your runs. Once you hit the wall, it’s difficult – both physically and mentally – to recover, so you’ll want to start adding more fuel more often to your runs. You mentioned that the GUs worked for you during the half-marathon, so I would recommend you start fuelling with these during your long runs. You can continue to add in some chews too (more fuel won’t hurt, and the combination of a few chews and a few gels shouldn’t make you feel too weighed down or sluggish).

You’ll want to aim for a goal of 45 grams of carb an hour, but try to avoid taking this all at the same time. Your system can only handle so many grams of carb at once, which is why I recommend taking in a bit of fuel every few kilometres. Be sure to chase each gel or chew or block with water, or else it’s likely to sit like a rock in your gut.

Below is a sample plan that may work for you. If the plan looks like it has way too much fuel, it might at this point in time. But don’t worry because you can train your gut to work up to this level of intake. So you might try to consume half the fuel during this weekend’s long run and then steadily increase until you get to a point where you are consuming enough fuel that you feel energised but not so much that you have GI distress or feel bogged down. Like I said before, long-run and race-day fueling takes a bit of trial and error. With trial and error, attention to detail, and good record-keeping, you can hammer out a plan that works for you. Best of luck in your training and fuelling!


Sample plan resulting in an intake of 45 grams of carb for each hour of a four-hour marathon

Keep the following in mind:

Most gels provide approximately 25 grams of carb. Gels should be chased with water (check the back of the package to determine how much). While your hands might get a bit sticky, it’s okay to consume part of a gel at one time and the rest a few minutes or kilometres later.

Most chews provide somewhere between 4 to 8 grams of carb per chew. Check the nutrition facts panel to determine how many carbs your brand provides. For the example below, I assumed that each chew provides 5 grams of carb.

Most sports drinks provide approximately 15 grams of carb per 235mL of fluid. Don’t chase your high-octane fuel (gels or chews or bars) with sports drink. Instead, alternate water and sports drink, always drinking to meet your thirst. The below plan lists carbohydrate-containing fuel only because it’s difficult to generalise a plan to meet every runner’s water and electrolyte needs. You’ll want to add in water according to the conditions and to meet your body’s needs.

  • 15 minutes – 2 energy chews
  • 30 minutes – 1 energy gel
  • 45 minutes – 1 energy chew
  • 1 hour – 1 energy chew (hourly total: 45 grams of carb)
  • 1 hour, 15 minutes – 1 energy gel
  • 1 hour, 30 minutes – 1 energy chew
  • 1 hour, 45 minutes – 120mL sports drink
  • 2 hours – 120mL sports drink (hourly total: 45 grams of carb)
  • 2 hours, 15 minutes – 1 energy gel
  • 2 hours, 30 minutes – 1 energy chew
  • 2 hours, 45 minutes – 1 energy chew
  • 3 hours – 2 energy chews (hourly total: 45 grams of carb)
  • 3 hours, 15 minutes – 120mL sports drink
  • 3 hours, 30 minutes – 1 energy gel
  • 3 hours, 45 minutes – 120mL sports drink
  • 4 hours – finished!

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