How to Fuel and Hydrate Long Runs in Indiana Summer Heat
If your long run has felt harder the last few weeks and your pace looks slower than it should for the effort, you're not losing fitness. You're running in July in Indiana, and the heat is doing exactly what heat does.
I coach a lot of adult marathoners building their base right now for fall races like the Indianapolis Monumental Marathon, and this time of year I get the same question on repeat: why does my easy pace feel so hard? Here's what I tell every one of them.
Your pace should slow down in the heat, and that's correct, not a failure. Heart rate climbs faster in the heat because your body is working to cool itself on top of the work of running. I'd rather see you run 30 to 45 seconds per mile slower on a long run in July than grind to hit a pace that was set for cooler weather. Chasing that number right now is how people end up hurt or gassed for August.
Start drinking before you're thirsty. By the time you feel thirsty on a long run, you're already behind. For anything over 75 minutes in the heat, I want my athletes drinking on a schedule, not waiting for a signal from their body that shows up too late. A good starting point is 16 to 20 ounces per hour, adjusted for how much you sweat and how hot it actually is that day.
Electrolytes matter more in summer than any other season. Plain water on a long, hot run can actually work against you if you're sweating out sodium faster than you replace it. I have my athletes add an electrolyte mix or tablet to at least one bottle on any run over 90 minutes in the heat. This isn't optional for serious summer training, it's part of the plan.
Move your long run earlier, or accept the trade-off. I know not everyone can run at 6 a.m. If you can, do it, the difference in temperature and effort is significant. If you can't, that's fine too, just know you're running in tougher conditions and adjust your expectations for pace and how you'll feel afterward.
Practice your race-day fueling now, not in October. Summer long runs are the best time to test the exact gels, chews, or drink mix you plan to use on race day. Your gut handles fuel differently under heat stress than it will on a cool November morning, so dial it in now while the stakes are low.
Here's the bigger picture. The runners who show up to their fall marathon fit and healthy aren't the ones who fought the heat all summer to hit arbitrary paces. They're the ones who respected it, adjusted, and let their fitness carry over quietly while everyone else was overheating and breaking down. If you're building toward a fall goal race and want a plan that actually accounts for where you're training and what the next few months look like, that's exactly what I build for the runners I coach.
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