Article: Whether you're participating in an Olympic sport or trying to improve your diet and exercise regimen, you'll want to consult with your doctor first. A doctor will be able to advise you on whether your diet or exercise plan will meet your nutritional needs, as well as whether your body can handle the physical stress of such a regimen. Staying hydrated is crucial for your day-to-day survival, and it's particularly important when you exercise. To properly monitor your hydration levels, you should weigh yourself before and after every workout so you know how much water you lost through sweat. It's imperative that you stay hydrated before, during, and after training to prevent dehydration.  Prior to your training session, drink at least 16 ounces of fluids two to three hours before exercising, then another 8 ounces of fluids about 15 minutes before your workout. You should also weigh yourself before exercising. During your training session, drink just enough water to prevent dehydration. Sip on water periodically whenever you feel thirsty. If you are able to closely monitor your body weight before and after training, you'll know approximately how much of your body weight is lost through sweat. Aim to keep that figure below two percent of your total body weight loss. Weigh yourself after training and drink 16 to 24 ounces of fluids for every pound of body weight you lost through sweat. If you're out of shape or working in intense environmental conditions like heat and high altitude, you'll need to drink more water than someone who has a more developed level of fitness. If you do not drink enough fluids before, during, and after exercising, your body will become susceptible to dehydration. Some common symptoms of dehydration include:  darker urine color muscle cramps headache nausea and/or vomiting elevated heart rate difficulty concentrating fatigue early in your training sessions and/or difficulty recovering after training Alcohol generally impairs your body's ability to perform by over 11 percent the day after drinking. There are no benefits to drinking alcohol during training periods. For this reason, it's generally recommended that athletes avoid drinking alcohol within 48 hours of training or competition. Some caffeine can improve your performance by increasing your endurance while improving your concentration and reaction time. However, too much caffeine can leave you feeling jittery, sick, and unfocused. For this reason, it's best to use caffeine strategically and in limited doses.  Everyone's tolerance varies, but it's generally recommended that you limit yourself to one to three milligrams of caffeine per kilogram of body weight. If you weigh 150 pounds (68 kilograms), that works out to 68 to 204 milligrams of caffeine. There are approximately 95 milligrams of caffeine in one 8-ounce cup of coffee. By comparison, there are approximately 26 milligrams of caffeine in one 9-ounce cup of green tea and 47 milligrams of caffeine in the same size serving of black tea. Drink caffeine approximately one hour before training or competing. If you will be training for over two hours, you may consume low doses of caffeine (80 to 120 milligrams) during your workout. Avoid caffeinated energy drinks. These have very high concentrations of caffeine and may contain derivatives of banned substances like geranium or ma huang, which could disqualify you from the competition. Vitamins and minerals are an important component of your diet. When you're training and competing, you'll need iron to help produce red blood cells and oxygenate your muscles. You'll also want to get enough vitamin D, which helps foster healthy bones, well-functioning muscles, and strong cell regrowth.  Athletes under 50 years of age need approximately 600 International Units (IU) of vitamin D each day and between 8 and 18 milligrams of iron. Vegetarians and vegans need almost twice as much iron (1.8 times the daily recommended intake). Good sources of vitamin D include fish, mushrooms, and fortified milk, soy milk, or juice. You can also get most of the vitamin D you need by spending at least 30 minutes in the sun each day. You can get rapidly-absorbed heme iron from animal products, while non-heme iron (which is not very well-absorbed) can be found in fruits, vegetables, legumes, and enriched grains. Some foods and beverages inhibit your body's ability to absorb iron, and should therefore be limited in your diet. These include coffee, tea, cocoa, and foods rich in calcium. You can increase your body's absorption of non-heme iron by pairing fruits and vegetables with foods rich in vitamin C. This includes citrus fruits and juices, strawberries, kiwis, tomatoes, broccoli, and peppers.

What is a summary?
Talk to your doctor. Drink enough fluids. Recognize the signs of dehydration. Avoid alcohol. Use caffeine wisely. Monitor your vitamin and mineral intake.