January 27th, 2009
03:05 PM ET

Tips to keep you on your feet

By Cristina Hernandez
CNN Medical Producer

I was in church with a friend on Sunday night. The weather outside was chilly, but the air inside the church felt, hot, thick, and many people were clustered together. It was stifling. As we both kneeled, I looked to the left and noticed that my friend had slumped down, with his eyes open and his arms were flopping loosely. At first, I didn't know what was happening, and I was terrified. My first thought was, "Did he faint or have a stroke? What's happening?" I called his name, too loudly for inside a church, and he didn't seem to hear me, even though his eyes were open. A few minutes passed and he seemed to regain his consciousness. I realized that he had fainted.

He didn’t give me the chance to help him sit down. I think he was embarrassed, and he went outside to breathe the cold, fresh air. I found him pacing in the chill. Thank goodness, he was OK. We went to my house, and I offered him a snack and gave him something to drink, which he said made him feel better. He explained that he had jogged seven miles earlier in the day, and he had eaten only two pieces of toast - clearly not enough food to replenish his energy after a long run. He also may have become dehydrated after he ran.

According to the Mayo Clinic, fainting occurs when the blood supply to your brain is disrupted, causing loss of consciousness. It usually lasts for just a few seconds or minutes. Fainting can occur for many reasons, and it becomes more common with advancing age. While my friend’s fainting incident was caused by skipping meals and possibly being dehydrated after his vigorous workout, it’s important to note that fainting after exercise can also signal a hidden health problem, and it’s a good idea to consult your health professional to rule out any serious medical issues.

It's important to fuel your body properly, before and after working out. According to Dr. Melina Jampolis, a physician nutrition specialist, if you have not eaten within three hours before a workout, it's a good idea to have a small, carbohydrate-rich snack, such as whole grain crackers, cereal, fruit, or half a peanut butter sandwich. Eat the snack 30 to 45 minutes before your workout to give you energy. If you plan to eat a meal within two hours after your workout, you probably don't need a post-workout snack unless you have exercised for longer than 90 minutes. In that case, a snack containing protein and carbohydrates - a fruit smoothie, yogurt, or cottage cheese and fruit - can help your body to rebuild or protect muscle, especially if the workout includes weight training. If you ate a meal within the last three hours, and are planning a short 30-minute cardiovascular workout, Jampolis says, you probably don't need any extra calories before or after you exercise. Avoid eating too much fiber before you work out. Fiber slows down digestion and can cause gas and cramping.

Don't forget the importance of keeping your body properly hydrated. Water is the best way to replace lost fluids. According to the American College of Sports Medicine, physical activity causes the body to lose water primarily through sweat, urination and breathing, even in cold weather. If you exercise during hot weather, dehydration can occur more quickly and impair both physical and mental performance. Symptoms of dehydration include thirst, rapid heartbeat, dark colored urine and dizziness, which can lead to fainting. The key to a successful and comfortable workout is to replace lost fluids by drinking plenty of water or other liquids before, during and after you exercise.

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