The 2024 NYC marathon was my fourth marathon, where I effectively dropped ten minutes off my personal best. And the reason is simple – I finally realized I needed electrolytes! I’m writing this to share what I’ve learned to help anyone else in the same situation.
Quick background
In my previous three marathons, I ran into the same problem – around mile 20/21, I hit the wall and had to start walking periodically for the rest of the race. It just felt like my body fell apart, and I always chalked it up to “that’s what hitting the wall feels like.” This got increasingly frustrating – even when I really controlled my pace in the first part of the race on a particularly easy (downhill!) course, this still happened.
Luckily, I’d been working online with a coach (HUGE shout out to Matt Day from McMillan) and he pointed out that I needed to think about electrolytes!
(This is where I should point out that I’d only ever drunk water on long runs & races – I avoided any electrolytes because I never wanted to drink something that I hadn’t used in training. Nothing new on race day!)
Fueling with carbs – what I was already doing
In the course of training for previous races, I’d already figured out how to get the carbs I needed. I learned to properly eat / carb load in the day or two before long runs (say over ten miles). I also learned about running gels and got into the habit of ingesting a gel about every 30 minutes in a long run or race (starting about an hour in). This approach worked. [Runner’s World article detailing this]
Fueling with electrolytes – the missing piece of the puzzle
My coach Matt pointed me in the direction of a free online calculator to help me understand what I needed – check it out here. My results:
With my existing gels, I was 44g of carbs per hour already – a good chunk of what I needed. And I had been fine with overall fluid intake – that 15 oz/hour was probably what I was getting at the water stations.
HOWEVER! The gels I had been were only giving me ~100 mg of sodium per hour – just 20% of what I needed. (1000mg/32oz = 500mg/16oz, so ~500mg/hour)
The NYC Marathon offers Gatorade Endurance Formula Lemon Lime drinks at aid stations. When I looked up the key stats, I saw that this provides (per 12 oz):
- 300mg of sodium
- 22g of carbs
Additionally, I found alternate gels – Gu Roctane Energy gels – that would provide 250 mg/hour of sodium (versus the 100 mg/hour from my previous gets).
Putting this together, if I drank about the same amount (roughly 12-15 oz of fluids per hour spread across various aid stations) and used the Roctane Energy gels, I would be taking in:
- 66 g of carbs per hour (44 from gels, 22 from Gatorade)
- 550 mg of sodium per hour (250 from gels, 300 from Gatorade)
Results – the 2024 NYC Marathon
For the first time ever, I ran an entire marathon without needing to walk a step!
I’ll confess as I got to miles 20 and 21 in the Bronx, I was pretty anxious – this was the point in my previous marathons (and training runs!) where I had previously hit that wall. But as I got through those miles and crossed into Manhattan I got increasingly confident that I’d solved this problem and was ready to go. (Seeing my family cheer me on around mile 22 was also a huge mood lift!)
Instead of falling apart on Fifth Avenue as the hill rises along Central Park, I felt strong! I was energized as I passed loads of people, including those other runners that were forced to walk. Those final miles in Central Park to the finish were electric – I felt strong and the race photos with some of my biggest smiles are along this stretch of the course.
Instead of my body feeling like I was on the ragged edge (despite my legs feeling fine), I ended the race feeling strong… but with very tired legs!
Going forward from here
I’m honestly much more excited to run more marathons in the future – being able to crack this bonking problem is incredibly motivating! Now that I know I can finish strong, I can train with a new purpose. And I know I’m absolutely capable of dropping a lot more time off my new marathon PB/PR.
I’m definitely going to tinker with the specific gels and electrolytes I use, when I take them, etc. Toward the end of the race I was getting annoyed by always taking electrolyte, and could/should have taken water once or twice instead. But I’ve found a solid platform of an approach that will serve me well.
I’m writing this because there are a bunch of resources about getting carbs during the race, I haven’t seen the same about electrolytes. If you feel like you’re fit enough to run a full marathon but have had problems “hitting the wall” harder than you like, I strongly encourage you to use a calculator like I did and figure out if you need to change your approach to electrolytes in your racing.
Jed Christiansen 