Exercise & NutritionPeople believe that if they exercise or play a sport, that they need extra supplements for their diet in order to maximise their metabolism. It is true that the more you get active the more calories you need. A balanced diet with proteins( including dairy products) cereals, fresh fruit and vegetables, should be more than enough for people who exercise. Supplements and vitamines are not essential in order to stay healthy.
Sources of Energy
During exercise, your cells obtain energy from glucose primarily through a process known as glycolysis. In a series of energy-releasing reactions, cells break down glucose in several steps to an intermediate called pyruvate. Additional glycogen is stored in the liver for use when your body needs it. When a muscle cell needs energy, it obtains it from molecules of adenosine triphosphate, or ATP. Although muscle cells have stores of ATP as well as stores of another molecule called creatine-phosphate that can regenerate ATP, these resources last for only 10 seconds at best. Glycogen stores must supply energy once the cell depletes ATP, and the energy from these stores lasts for up to 1.6 minutes. Once the body exhausts these stores, additional energy pathways become involved to supply more glucose and other energy sources to meet continuing demand. By continious exercising, the body uses glycogen sources and fat. Therefore, if you want to lose weight, the total energy you exhaust during exercise should be more that the amount of calories of food and drink you have taken.
Carbohydrates are one of three classes of food called macronutrients (the other two are fats and protein). The term “carbohydrate” is a big umbrella, including everything from table sugar to cauliflower. The basic unit of a carbohydrate is a monosaccharide or simple sugar (such as glucose or fructose), but these simple sugars can be linked together in infinite ways, and will have very different effects on the body depending on their arrangement.The body can obtain everything it needs to survive from protein, fats and the right kind of dietary carbohydrates (or good carbs), like vegetables, which offer many valuable components such as antioxidants, fiber, vitamins and minerals.Good carbs are carbs that don’t raise blood sugar too high or too quickly. The best carbohydrates (like vegetables) are found in unprocessed whole foods that are rich sources of phytochemicals - plant compounds, which protect against cancer, heart disease and other illnesses. Many phytochemicals are natural antioxidants and many are anti-inflammatory. Carbohydrates like vegetables and fruits also contain tons of important vitamins and minerals.
Protein recommendations for endurance and strength-trained athletes range from 1.2 to 1.7 grams/kg body weight. This protein intake can generally be met through diet alone, without the use of protein or amino acid supplements.
Adequate fluid intake before, during, and after exercise is important for health and optimal performance. Two to three hours before exercise, drink 15-20 ounces or water, and then another 8-10 ounces ten to fifteen minutes before exercise. During exercise, drink 8-10 ounces every ten to fifteen minutes.
For intense endurance exercise lasting more than 90 minutes or when you are exercising in an extreme environment (heat, cold, or high altitude), the goal is to drink to stay hydrated and to provide carbohydrate so that blood glucose levels are maintained.
Before you exercise
Food eaten before exercise should be relatively low in fat and fiber, moderate in protein and relatively high in carbohydrate to maximize maintenance of blood glucose.
Within 30 minutes after exercise, dietary goals are to provide adequate fluids, electrolytes, calories, protein and carbohydrates to replace muscle glycogen and promote recovery. A carbohydrate intake of approximately 0.5-0.7 grams per pound during the first thirty minutes and again every two hours for four to six hours will be sufficient to replace glycogen stores. Protein consumed after exercise will provide amino acids for building and repair of muscle tissue. So adding protein 0.2 g - 0.5 g/kg/day to carbohydrate at a ratio of 3 - 4:1 (Carbohydrate: Protein) may further improve glycogen re-synthesis so properly refuel for future exercise.