Upset stomach?

I'm starting to adopt more running into my weekly duties. Whereas it was cyling 6 days a week, it's now running 2 or 3 days a week on top of riding the other days, with varying distances of 3-5 or 6 miles. I'm a 5 small meals a day eater, and generally on my way home from work, I'll have an apple and some water because I go right out and either ride or run when I get home. I've noticed that lately, I've gotten stomach aches. I'm well aware that this isn't something out of the ordinary, but what causes it? And how can I stop it? My legs have more miles in them but my stomach doesn't and it's bumming me out.

My whole digestive system is much more sensitive running than it is on the bike. It's been a matter of trial and error, figuring out what I can tolerate (fruit is right out, for one thing - as is anything with much fructose in it at all). Unfortunately, you're probably just going to have to experiment and learn what works for you.

Also make sure that you're getting enough sodium. Electrolyte imbalances are a big cause of nausea and diarrhea.

I have a similiar problem. I used to love yogurt with homemade granola as my afternoon snack, but now I know I can't eat that on run days (I run after work). It actually gives me horrible heartburn, of all things.

Lately, I've been happy with an apple and 1-2 oz of low fat cheddar. Just a plain apple would probably leave me with stomach distress, too. For whatever reason, the addition of the cheddar keeps things on an even keel (protien? fat? who knows...)

I agree with Oak - the best way to figure it out is to experiment.

The apple and cheese balance does make sense. I read somewhere that sometimes dairy causes it, alone. I also read dehydration causes it, your breathing, etc...

Maybe I'm just not lucky enough to have a strong stomach when running.

As you run more, your body may adapt to having food in your tummy, too. After running a lot, I can eat different foods before running than I can when I spend weeks not running at all, and closer to the time when I start running. So, don't despair too much that it's a permanent or difficult affliction. ;)

It may be the amount of time between when you eat and when you run, it might be the high fiber/sugar foods. Maybe switch to a banana instead of an apple, or try adding the protein (I usually try to pair a little protein with carbs in a snack anyway).

Running is definitely harder on the tummy than riding - though if I go out and do hard intervals, hills, or sustained higher intensity in any way on the bike, it feels a lot more like running than a nice smooth commute or afternoon ride.

I like apples but I can NOT eat them on long bike rides, they give me an upset stomach. Bananas, oranges, tomatoes, strawberries are all fine. It's only apples and apple juice that do it.

I like toast and peanut butter with an orange before a morning run. But before I moved to Colorado (the land of little air), I used to be able to eat anything before/during a run (except pizza or almonds, for some reason).

For super-long marathon training runs or trail runs that might take way longer than their mileage would suggest, I like to bring ginger candies along. Sometimes, if I'm not cramping because I ate something obviously stupid (like pizza) a kids-size soda will help me, too.

One other random hint - I believe gulping your drink of choice instead of sipping is supposed to help, also. I'm not positive about the science behind this but it seems to work for me. (I don't suggest this if the beverage of choice is the soda).

A full stomach stimulates emptying. So it might depend on whether the distress is in the upper or lower GI. You'll stay better hydrated if you gulp, and have less stomach sloshing, but it's possible it might cause more lower GI issues?

Thanks for these suggestions thus far. I may need to reconsider the apple on my car ride home from work if I'm running that night. My goal is 10 miles by the spring, so I better start experimenting now to make my life less miserable as the miles increase.

Thanks! :)