I agree with whoever said it could be from running then stopping quickly. I live in Texas. It is VERY hot and humid here all the time, so I have experienced light-headedness after exercise before. I've passed out once at a football game while climbing the stairs up into the stadium as well. After you run, especially in the heat, it is important to walk for 5-10 minutes instead of suddenly stopping. I also think Gatorade is better than water when it is extremely hot and humid. I always take Gatorade on the bike, and I eat a Clif bar before all my runs and drink Gatorade afterward. You sweat so much more, so you need all the extra stuff in Gatorade. You could have passed out from low blood sugar, dehydration, stopping too fast, anemia, or any number of things. You might just get a blood test done to check your iron and blood sugar. A friend of mine recently discovered she is anemic, though she has never had symptoms. Taking a multivitamin can help as well as just getting enough leafy greens. I am terrible about eating those good things AND about getting enough to drink, but I'm really trying harder in both areas. You may have just not had enough to drink before you started your run since you didn't necessarily "plan" for it. You also need to listen to your body while running. I'm sure you had signs earlier in the run. Take walk breaks often. I have to take them when it is really hot. Jeff Galloway talks a lot about walk breaks in his book, and he says you should take more in hot weather. If you normally take none on a 3 mile run (like me), then you may have to take one every mile when it is really hot. You don't lose anything taking walk breaks. I've begun doing them, and it is great because I feel like I can run forever!
Kelli
