Nutrition

 

Overview on Nutrition from Nutrition for Swimmers by Ernie Maglischo

  1. Good nutrition supersedes training because it is essential for proper training to take place (p4)
  2. The energy required for swim training has been calculated at between 6 and 10 calories per minute or 360 to 600 calories in one hour. (p 6)
  3. At one time starches constituted nearly 80% of our carb intake but over the years there has been a steady increase in consumption of sugar intake from 20% as they were in the past to over 50%. Sugars contain no vitamins, minerals and fiber that are found in complex carbs. Foods such as honey, sugar, syrup, and candy are almost entirely composed of simple sugar (p 9)
  4. Need to maintain a “normal” blood glucose level during training as it not only supplies glucose to muscles it supplies energy to the brain for proper functioning. Blood glucose levels that are too low may result in the swimmer can become disoriented, dizzy and if severe enough become unconscious. (p 10)
  5. Replenish glycogen can take 24 to 48 hour and depends on total caloric intake and carbohydrate make up of the diet. Fatty diets will not give enough carbs to replenish glycogen stores. (p 10)
  6. Daily diet of 500 to 800 grams of carbohydrate or more will replenish muscle and liver glycogen stores in approximately 24 hours. Need 2000 to 3200 calories from carbohydrates – pasta, grains, breads, potatoes, and beets. (p 12)
  7. Our fast food diets are based on more fat and not enough complex carbohydrates — 40 to 50% of the calories are from fat and only 40 to 50% of the daily caloric needs come from carbohydrates. In addition, much of the carbohydrates come from sugars in the form of baked goods, candy, and carbonated drinks. (p 13)
  8. Simple sugars will raise the blood glucose levels and within 2 hours the decrease in blood glucose will leave the person lethargic. By contrast starch forms of carbs produce a smaller but longer lasting blood glucose increase that maintains a high level of glucose in the blood for a much longer period (p 13)
  9. Many swimmers need to cut their fat consumption intake in half to meet the recommended range of 15% to 20% of their calories from fat. (p 18)
  10. Athletes should not eat doughnuts, Danish, cookies and other bakery products to their hearts delight in the mistaken belief they are good sources of carbohydrates. Croissant calories are 38% from carbs and 60% from fat. (p 19)
  11. Protein (amino acids) is the building block of body tissue – muscle tissue, mitochondria, myoglobin, and hemoglobin. (p 20)
  12. Protein is the energy source for muscle contraction. (p 20 Fig 6)
  13. Protein in the diet should be between 10% and 15% of the calories. – 1.5 to 2.0 grams per kilogram body weight (p 21)
  14. Preferred to increase protein by eating more fish, chicken and turkey not increasing red meats as they have 25% saturated fats. (p 22)
  15. The body stores 3 grams of water for each gram of glycogen so when training and glycogen is used up the body looses water. Athletes should drink 6 to 10 8 Oz glasses of water per day to replace the water used during training.
  16. Vitamins are catalysts for the metabolic process that furnishes energy and build tissue. (p 25)
  17. B-complex vitamin role is instrumental in the metabolic processes that release energy for muscle contraction. (p 26)
  18. B1 deficiencies may slow the metabolic rate, reduce energy, cause the myelin sheaths around nerve fibers to degenerate weaken cardiac muscle tissue. B1 can be safely supplemented. (p 26)
  19. Athletes should view vitamin-mineral supplements as safeguards, not quick energy foods that improve performance (p 42)

Dietary Practices to Improve Training

  1. Blood glucose falls within 2 to 3 hours of eating, so eating more frequently than once every 5 to 6 hours should maintain it at a higher level so more glucose can enter the muscles for storage. (p 64)
  2. Eating high-carb meal within 1 to 2 hours after training increases the rate of liver and muscle glucose replacement. ( p 64)
  3. Between Meal Snacks for swimmers – fruits, fruit juices, vegetables, grains, and cereals. High Carb products sold in liquid, powder, and bar forms are also good. Snacks; should be high in cabs 60% or more and low in fat. Protein content is not important. (p 64)
  4. Athletes doing two a days frequently train when their muscle glycogen supplies are low. At these times, they run the rise of combusting muscle proteins for energy. (p 65)
  5. Use carbohydrate drinks and snacks before and during training. (p 65)
  6. Before training -low to medium glycemic index carbs to maintain blood glucose at a higher level during training– want diet to be 60-75% carb and 10-15% fat (p 66 and 67)
  7. During training consume high carb drinks to maintain high blood glucose levels– 50 to 70 grams per hour [ Gatorade – need 64 to 72 oz per hour]. (p 70)
  8. Four rules to govern choice of fluid to use during training: 1) enough carbs to maintain blood glucose levels 2) pass thru digestive system quickly to reach the muscles 3) contain some salt to stimulate glucose absorption from the stomach to the blood stream and 4) palatable (p 68)
  9. Shortly After training – – high glycemic index carbs to be absorbed into the blood stream faster (p 72)- want some protein to help with uptake of carbs and muscle repair (p72); consume 150 to 300 grams of easily digested carbs immediately after training – 40 to 80 grams of carbs in small snacks eaten each hour for the next 4 hours (p 71)
  10. High Carb Energy Bars – PowerBar Performance little over $1.00 per bar with 46 grams of carb and 9 g of protein; also PowerBar makes a product called Energy Blast which are bite size (note: Orange favor has no caffeine) for a total of 49 g of carbs.
  11. Glycemic index is a measure of how quickly insulin spikes and sends glucose into the blood stream. So High Glycemic foods will cause rapid release of insulin and glucose into the blood stream while Low Glycemic food leave the stomach slower and cause a lower but longer lasting insulin increase and glucose increase.

Dietary Practices that can improve Performances in Competition

  1. The Pre-Meet Meal has little to do with improving performance; rather the athlete should begin two to three days before competition increasing carb content of their meals, and at the same time a reduction in the quantity and intensity of training so muscle glycogen will not be depleted prior to competition. (p 74)
  2. A sensible pre-meet meal should be small and easily digestible – 600 to 800 calories most of the calories from starchy carbs (100 to 150 grams); avoid red meat, spicy and fried foods – and eaten 3 hours before competition. Toast, muffins, cereal, pancakes, waffles, and noodles are good choices. In the past pizza, spaghetti, tacos and burritos have been recommended but they are not good choices. (p 75 & 76)
  3. If the swimmer is swimming multiple events with 1 to 2 hours between events the snack should be something that does not lay on the stomach, undigested by race time and without causing nausea. These should be high glycemic foods eaten as soon after the first competition as possible. (p 76)
  4. If the events are swum within an hour of each other, the best strategy is to drink a high carbohydrate drink immediately after the first event and then every 15 or 30 minutes until within 15 to 30 minutes of the next event. These can be commercially prepared liquid, fruit juice, or a commercial powder or gel. Soft drinks are not recommended as they are carbonated. Let your thirst be your guide. (p 76 & 77)
  5. Some of the “quick energy” foods, candy, honey, and syrups that are mostly sugar will not hinder performance but they ae not the best choice for pre-training or post competition snacks. Complex carbs are the better choice. (p 77)
  6. Carbohydrate Loading can be accomplished by simply reducing the volume and intensity of training and eating high carb diet – 300 to 500 grams per day — three days before competition works just as well as the more complicated carb loading procedures. The enzymes in muscles will store extra amounts of glycogen just like they do following the longer loading procedures. (p 80)

Other Information

  1. Increasing muscle tissue is the key to improved swimming. The stimulation of heavy resistance training and sprinting along with caloric intake all play a role in encouraging muscle growth. Additional caloric intake of 2500 calories is needed for maintenance and training to gain 1 lb of muscle tissue. The intake should be spread over 1 to 2 weeks with 100 to 300 added calories per day. (p 86)
  2. Swimmers who feel they need to lose weight should not diet but simply reduce the amount of fat in their diet and increase the carb and protein intake. (p 87)
  3. Creatine may be less than adequate in vegetarian diets. Athletes can supplement their diets by taking 2 to 3 grams per day to help with muscle building and recovery. (page 98)